ACCE Bulletin Apr-Jun 09

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Vol. No. 8 No. 4 QUARTERLY

ofAssociation of Consulting Civil Engineers (India)

BULLETINAPRIL - JUNE 2009

Silv

er

JubileeY

ear

198420

09

Winner of the ACCE SARVAMANGALA AWARD 2009 for Excellence in Construction of Civil Engineering Projects

Bulletin of ACCE (I) 3 April - June 2009

ACCE (I) Office BearersChairman : Dr. M. N. Hegde

National Advisors :D. Ranganth, Nirmal Prasad A, Dr. R. Jagadish, Dr. Manamohan R. Kalgal,Dr. V. Ramachandra, B.S.C. Rao, Ajit Sabnis, Avinash Shirode, Srinivasan S.P.,Moorthy K.G.K., S.N. Karnik, Jain L.K, N.R. Ashok, Ratnavel S.

Technical Editors : IndustryProf. T. Senthilnayagam, R. Srinivasan, S. K. Jain, V. P. Ponnuswami, Tigadi N. S,H. V. Manjunathaswamy, Mukund Kamath, R. K. Desai

Technical Editors : Academic InstitutionsDr. Sharada Bai, Dr. R. V. Ranganath, Dr. M. C. Nataraja, Dr. D. S. Prakash,Dr. M. U. Aswath, Dr. R. N. Pranesh Secretaries of all Centres (Ex-Officio Members)

Bulletin Committee

ACCE BULLETINVol. 8 April - June 2009 No. 4

Umesh B. Rao PresidentA. M. Shingarey Vice-President (West)Dr. A. R. Santhakumar Vice President (South)B. V. Ravindranath Secretary GeneralB. N. Raghunath Treasurer

S. Pichaiya Imm. Past PresidentDr. Manamohan R. Kalgal Imm. Past Secretary General

Printed and published by Dr. M.N. Hegde on behalf of the Association of Consulting Civil Engineers (India) and printed at Vijayanataraj Printart Industries, S.C. Road, Basavanagudi,Bangalore – 560 004 and published at 2, UVCE Alumni Association Building, K R Circle, Bangalore – 560 001. Editor: Dr. M.N. HegdeMAG(3)/NPP/166/2003-04, CMM/BNG/DELL/PP/156/21-2002

C O N T E N T SABOUT COVER PAGEWinner of the ACCE SARVAMANGALA AWARD 2009 forExcellence in Construction of Civil Engineering Projects

awarded to B.G. Shirke Construction Technology Pvt. Ltd.,Bangalore for Excellence in Construction of

VIDHANA SOUDHA SOUTH BLOCK (Vikasa Soudha)The magnificent Vidhana Soudha is the largest legislature cum secretariatbuilding in the countr with around 6.4 lakh sq. ft. of area. This buildingcould not house all the elected MLA’s in this one building. It was Shri S.M.Krishna, Ex-Chief Minister, who decided and finalized the Vidhana SoudhaSouth Block to be constructed with a built up area of around 6.00 lakhsq.ft. VSSB was later rechristened as ‘Vikasa Soudha’. The ‘VikasaSoudha’ was planned and executed by the Karnataka Public WorksDepartment. The building was planned to match the existing building intotal. The ‘Vikasa Soudha’ is situated just adjacent to the Vidhana Soudhain the heart of the city; the state secretariat building is essentially Indianin style. It is built mainly ont he union of Dravidian, Rajasthani, Chola andKannada Style of architecture, which evolved in India. The ornamentalmotifs, floral patterns and chiselled geometric designs are all distinct andnot a single design has been repeated. All the door and windows are withteak wood. The floral motifs of the stone-carvings are Dravidian in styleand are drawn entirel from the temple - craft of Karnataka and Tamil Nadu.Thus the Vidhana soudha and Vikasa soudha showcase the best of SouthIndia’s Indegeneous architectural styles.

The stone structure is built entirely with the granite executed from thevicinity of Hesaraghatta, Mallasandra, Avalahalli, Koira Quarries. The grandentrance of the Vikasa Soudha faces the Attara Kacheri (now called theHigh Court) another imposing structure and the cubbon park.

Around 3000 labourers and 1,500 sculptors were deployed for the proejctunder a team of dynamic engineers from B.G. Shirke ConstructionTechnology Pvt. Ltd. and the Karnataka Government PWD. The Total soneused for this project is about 4.00 lakhs c.ft.

The entire building of Vikasa Soudha covers an area of 638068.00 sq. ft.of built up area. The building consists of three basements for car parking(each of 7958 sq. mt.) a around floor and 4 floors above with 6880 sq.mt.in each floor. On the eastern side a porch with 8 tall decorated cylindricalgranite columns of 40 ft. in height.

Granite stones of different colours found in and around Bangalore wereused for the building. The building’s four corners have four towers, supportingdomes topped by metallic Kalashas.

This is the only Government building having the following features :• Sub surface drainage system. The excess water from the sub

surface flows to the Cubbon park.

President’s Message ...................................... 4

From Secretary General’s Desk ........................ 5

From the Editorial Desk .................................... 5

Slurry Infiltrated Fibrous Concrete (SIFCON)-an Experimental Study ..................................... 6

Rethinking Sustainability .................................11

The New Lightweight Structure Tensairity ........ 13

Review and Design of Flat Plate/Slabs Construction in India ............................. 17

Tall Sustainability—An Urban Imperative ......... 21

Events at Glance ............................................ 29

Infrastructure Health Monitoringfor Management .............................................. 37

Role of Admixtures role Admixtures. ............... 44

When Structures Move .................................... 48

News From ACCE (I) Headquarters ................ 54

News From ACCE (I) Centres .......................... 54

Forthcoming Events ........................................ 56

ACCE (I) Membership Additions ...................... 56

Professional Directory ................................... 57

Thanks to Patrons ....................................... 58

• Solar power of 100 KW.• Fire fighting system• Air Conditioning• Two nos Capsule Lifts along with six passenger lifts.• Pedestrian subway connecting south side of ‘Vidhana Soudha’ and

North side of ‘Vikasa Soudha’.• Trenchless excavation to drain out excess water fromthe sub surface

to Cubbon Park


PRESIDENT’s MESSAGE

Dear Members,

It has been pleasure being President of ACCE for the tenure year 2007-2009.It gave averygood opportunity of meeting members at various centers during Govrnning Council meetings,seminars, technical meets or associated functions. It was always very warm welcome,greathospitality and very homely but very meticulously planned and executed programmes along withappropriate topics and technical contents. I enjoyed this term and will be cherished all along. I amthankfull to all of you for the cortsey extended to me.

Ensuing year is our silver jubilee year and we need to celebrate it in befitting manner.May beby holding technical meets,workshops,seminars,round table conference even places we do nothave centers. These location can be in the proximity of existing centers or in that region. The topicscan be of interest to suit considering requirments locally, regionally, nationally. I am of the opinionthat one issue which is of national importance is trainnig of personal involved such asdesigners,software for analysis,engineering,design,detailing,quantity survey etc. We also need tointeract, collabrate, cooperate with educational institutes, NGO, youngsters to upgrade knowledgeas well generate interest to learn and train to perform better.

Engineer Avinash Shirode, Nashik, is the President elect for the next term. He is a versitleperson and has been very actively involved not just on engineering proffession but on matter ofengineering societies. I am sure he will take ACCE (I) to much higher heights.

This will be the last bulletin in which I will be addressing as President. Hope to see all of you atDavangere for the AGM and installation of New Team.

Wishing you good bye and all the best in your profession.

UMESH B RAOPresident- ACCE(I)


Dr. M. N. HEGDEChairman, Bulletin Committee

Email: [email protected]

From the Editorial Desk

From Secretary General’s Desk

B. V. RAVINDRANATHSecretary General

Dear Members,

It is to inform you all that my term as Secretary General for last two years has come to an endmaking way for the new team and new Secretary General to take over for 2009-2011.

It is time to pay my tributes with thanks to the President, Governing Council Members and Staffat Head Quarters for extending their fullest support in conducting my term smoothly andsuccessfully. I wish to express my sincere thanks to all members for extending their supportduring my term. It was indeed a great time of my career to meet many senior members ofACCE(I), get their advice and guidance apart from visiting various places to further the activitiesof association. It was indeed an eye opener for me to know about the excellent brotherhoodexisting among our fraternity members. The opportunity to meet and hear lectures from doyensin our field and share platform with them was unforgettable one. The term also showed how anindividual can be part of an association for the greater causes of both.

With the new team set to take over at the AGM at Davangere, I wish them success in theirendeavors. I am hopeful to interact with you all in a different capacity under new team.

Looking forward to meet you all to thank you in person at AGM at Davangere.

Dear fellow members,

I tried my best to retain the standards of the bulletin. Unfortunately, I could not fulfilmy own expectations for the bulletin. I wish that the bulletin will soon be convertedinto a Journal.

I thank all members for their criticism, suggestions and support / encouragementduring last two years of publication of the bulletin. I also thank the members ofAdvisory and Editorial Committee for their valuable contribution and involvement. Ithank Mr. S. D. Anne Gowda, who always takes personal interest in the publicationof the bulletin. I take this opportunity to thank Mr. Ekambaram and Mr. Harish fortheir co-operation and assistance. I sincerely thank Mr. Sathishchandra for wonderfulDTP work and timely completion of the work.

I am grateful to President and Secretary General for their constant support &encouragement.

I wish next team all the success and wish that the bulletin will be taken to a newheight. I congratulate the new team under the leadership of Mr. Avinash Shirodeand Dr. M. U. Aswath, and wish them all the best.

With warm regards,


SLURRY INFILTRATED FIBROUS CONCRETE (SIFCON)-An Experimental Study

Dr. Aswath M.U., Professor in Civil Engineering, BIT, Bangalore-4 Sreenivas S.R., Consulting Engineer (Former PG Student BIT)

ABSTRACTSlurry infiltrated fibrous concrete SIFCON is a relativelynew high-performance and advanced material and canbe considered as a special type of steel fibre reinforcedconcrete (SFRC). SIFCON is a unique constructionmaterial possessing high strength as well as large ductilityand far excellent potential for structural applications,when accidental or abnormal loads are encounteredduring service. SIFCON also exhibit a new behavioralphenomenon, that of ‘fibre interlock’ which is believed tobe responsible for its outstanding stress-strain properties.

In this view an attempt has been made to study thebehavior of SIFCON in compression and tension. Total87 specimens were cast and tested. 57 cylinders and30 cubes with fibre length of 40mm, 50mm and60mmand with fibre percentages of 6, 8, and 12 wereinvestigated using super plasticizer to improve watercement ratio. In the present investigation the study oftensile and compressive behavior of SIFCON is done fordifferent variation in fibre percentage and fibre length.

Keywords: SIFCON, steel fibre, cylinders, cubes,compression testing, tensile strength, water cement ratio.

1.0 INTRODUCTIONThe technique of infiltrating layers of steel fibres withPortland cement based materials was first reported byHaynes [1968]. Lankard [1979] modified the methodused by Haynes and proved that if the percentage ofsteel fibres in a cement matrix could be increased, onecould get a material with very high strength propertieswhich he named as SIFCON. Later he extended theapplication of SIFCON to refractories [1982]. Theengineering properties of SIFCON along with a numberof successful applications were again investigated byLankard and Newell [1984]. Homrich and Naaman [1987]studied its stress strain properties in compression.Naaman [1987] also investigated the use of SIFCON inconnection with seismic resistance frames.Parameswaran et al [1990] investigated the behaviour ofSIFCON under impact, abrasion on flexural loads. Theyalso studied the feasibility of different ways of makingSIFCON and measured their relative toughnesscharacteristics [1991].

SIFCON has already been successfully used abroad forthe construction of structures subjected to impact, blast& dynamic loading and also for refractive applications,overlays and repairs of structural components because

of its high tensile strength and ductility. In the presentinvestigation compressive strength, Young’s modulus andPoisson’s ratio of SIFCON are studied. The tests wereconducted on specimen caste by SIFCON matrix withdifferent fibre volume contents.

2.0 OBJECTIVE AND SCOPE OFINVESTIGATIONFrom the literature study conducted, it appears that anumber of researchers were concentrated their attentionon the study of various strength properties with constantl/d ratio and varying percentage of volume of fibre. In thepresent investigation an effort has been made to studythe properties of SIFCON keeping both 1/d ratio andpercentage of volume of fibre as variables. Theexperimental investigation is related to compression splittensile and modulus of elasticity of slurry infiltrated fibrousconcrete. The cubes and cylinders of standarddimensions were cast and tested as per I.S.specifications after curing 7 & 28 days. In thisinvestigation the parameters adopted as constants arethe water cement ratio, diameter of steel fibre andcompaction (table compaction) period. The variedparameters are: 1.The aspect ratio (1/d) of the fibres(40, 50 and 60) 2.Percentage of fibre (6, 8 and 12)

3.0 TEST PROGRAMMEThe present experimental investigation focuses attentionon the compression and split behavior of slurry infiltratedfibrous concrete. Coarse aggregate has been replacedby the fibre in percentage of 6, 8 and 12 by total volumeof specimen. In all the mixes the water cement ratiowas kept constant (0.5) using super plasticizer (SP 337)at 7 ml/kg. The aspect ratios of fibre are 40, 50 and 60.Ordinary Portland cement is used in the experimentalwork.

The test program consists of carrying out compressivetests on cubes and cylinders, split tensile tests andmodulus of elasticity tests on cylinder. The total numberof specimens for all mix proportions is 87, which consistsof 30 cubes, and 57 cylinders. Each cube of size 150 x150 x 150 mm, cylinder of diameter 150 mm and length300 mm.

Each mix consists of 3 cubes and 6 cylinders for eachpercentage of fibre and for each aspect ratio of fibres.Thedetails of constant, variable parameters and specimendetails are as shown in below table.


Varied parameters Type of specimens

Constant parameters Length of fibre % ge of Cubes Cylindersvolume of fibre 15x15x15 cm 15x30 cm

W/c ratio = 0.5 40 mm 6 3 68 3 612 3 6

Compaction period 2 minutes 50 mm 6 3 6(Table Vibrator) 8 3 6

12 3 6

Dia. of fibre = 1 mm 60 mm 6 3 68 3 612 3 6

Plain mix (1:1.5:3) 0 3 3

4.0 EXPERIMENTAL INVESTIGATION ANDPRESENTATION OF TEST RESULTS4.1. GeneralAn experimental study is conducted on slurry infiltratedfibrous concrete (SIFCON). The design mix consists ofhigh strength slurry with various percentage of fibre byreplacing coarse aggregate. Cubes and cylindricalspecimens cast and tested for compressive strength,split tensile strength. Experimental study is carried outto investigate the strength variation in concrete byreplacing coarse aggregate by fibre and to find out thestrength properties of SIFCON.

4.2 Materials:Cement: Ordinary Portland cement of 43 gradeconforming to ISI standards. The cement is tested forits various properties as per IS 8112-1989. The resultsare Normal consistency is 30%, Initial setting time is45 minutes, Final setting time is 7 hours and Specificgravity is 3.08.

Fine Aggregate (Sand): River sand from the localsource. The specific gravity of the sand is 2.65 whereas its fineness modulus is found to be 2.99 confirmingto zone – II.

Water: The potable fresh water, which is free fromconcentration of acid and organic substances, is usedfor mixing the slurry.

Super Plasticizer: SP 337 super plasticizer at 7 ml/kgis used to improve water cement ratio.

Fibres: Black wire fibre of 1.0 mm diameter with ultimatetensile strength of 390 N/mm2 is used. The fibres arecut to required lengths using shear cutter. The fibre lengthof 40, 50 and 60 mm are used.

4.3. Fabrication and CastingThe cylinders were cast in steel moulds of diameter 150

mm and 300 height and the cubes are cast in steelmoulds of inner dimensions of 150 x 150 x 150 mm.

For all test specimen moulds are kept on table vibratorthe moulds are filled with fibre in random manner ofcalculated volume. For each percentage of fibre and foreach aspect ratio of fibres 3 cubes and 3 cylinders werecast. After placing the fibres in the moulds the slurrywas poured into the fibre bed and vibrations were effectedby table vibrator. The vibration was effected for 2 minutes,for each mould and it is maintained constant for all thespecimens.

4.4 Testing of specimensAfter curing the specimens in water for a period of 7 and28 days they were allowed to dry under shade and thenwhite washed. The specimens were tested forcompression and split tensile strength.

Compression Test: The test results are tabulated for 7and 28 days in table 4.2.and 4.3. The variations of thecube compressive strength for the three types of aspectratios versus volume percentage of fibres are shown infigures 4.2.and 4.3.

Split tensile strength test: The tensile strength ofconcrete is calculated using the formula 2P/ (3.14 D xL) where P=maximum load, L=length of cylinder and =diameter of cylinder.

Split tensile strengths for all cylinders tested werefurnished in the table no: 4.4. The variations of the splittensile strengths for the aspect ratio of fibres (40, 50,and 60) versus volume percentage of fibres are shown infig.4.4

Modulus of elasticity test: The typical stress stainrelations are shown in figures: 4.5 to 5.3. The modulusof elasticity was determined at 30% of ultimate strengthof cylindrical specimen. It was observed that the linearitybetween stress and strain exhibits up to 30% ultimate


strength. The modulus of elasticity values determined inthis investigation is furnished in table no: 4.5. The failureload was taken as cylindrical strength of the specimen.The modulus of elasticity is determined by taking initialtangent modulus for each percentage of fibre and for eachaspect ratio of the fibre.

4.5. General observations:It was observed in compression tests that the plainconcrete cubes failed suddenly in a brittle manner whereas the SIFCON cubes produced significant cracks withincrease in the post cracking strength.

In the case of cylinders it was observed the top andbottom surfaces of plain concrete cylinders were crushedwhere as in the SIFCON no such crushing was observedwhich is an indication of the ductility of slurry infiltratedfibrous concrete.

5.0 DISCUSSION OF TEST RESULTS5.1. Compression TestCylinders: Typical stress strain curves in compressionare presented in table 4.4. The SIFCON specimensbehave in a very ductile manner compared with planeconcrete (1:1.5:3) specimens. It may be observed thatthe energy absorption is more in SIFCON specimens.

The energy absorption effect can be achieved in twoways. One is increasing the fibre length by keepingvolume of fibre constant. The other one is by keepingthe fibre length constant and varying the percentage offibre.

From table 4.4 it may be observed that as the percentageof fibre increases the E value increases. The E value forSIFCON specimens is more compared with plain concretespecimens. This may be due to difference in matrix.The stress distribution is more effective in SIFCONspecimens.

Cubes: It was observed that the compressive strengtheffect is more with increasing the percentage of fibre forparticular l/d ratio. The compressive strength was isincreases by increasing the length of fibre by keepingvolume of fibre constant.

5.2. Split Tensile Test:From table 4.4 and figs4.4, it is evident that higher valueof tensile strength is obtained by increasing the fibrevolume with 1/d ratio as constant variable.

The higher split tensile strength may also be obtainedby increasing the fibre length with constant percentageof volume of fibre. But the increment rate is less in latercase.

6.0 CONCLUSIONSConclusions: From the limited tests conducted, thefollowing tentative conclusions can be drawn based onthe results presented. It should be noted that the results

pertain to the use of straight steel fibres.

• The higher compressive strength may be obtainedusing higher volume of fibre and 1/d ratio, providedwith good bond between matrixes.

• SIFCON exhibits extremely high ductility• An increase in fibre length leads to an increase in

both compressive strength and tensile strength.• At constant fibre length compressive strength is

directly proportional to the volume fraction of fibres.It may be noted that after a certain fibre loading thebond strength goes down because of lack of matrixpresence in between the fibres.

• The relation between compressive strength andtensile strength for different aspect ratios is linear.

Table 4.2 Cube compressive strength of testedspecimens: 7 DaysFor plain concrete (1:1.5:3) mix Compressive strength =46.67 N/mm2

Sy Percentage Fibre Length Fibre Length Fibre LengthsNo of Fibre 40mm 50mm 60mm

Average Ultimate Compressive

Load Stress Load Stress Load StressTonnes N/mm2 Tonnes N/mm2 Tonnes N/mm2

1 6 92.5 40.5 100 44.3 111 49.82 8 95 42 102 45 113 50.33 12 99 43.5 111 48.3 119 54

Table 4.3 Cube compressive strength of testedspecimens: 28 DaysFor plain concrete (1:1.5:3) mix Compressive strength= 46.67 N/mm2




1. 6 104 46 108.5 48.5 116 51.52. 8 106 47 110 49 118 52.53. 12 112 49.5 114.5 51.5 125.5 55.5

Chart Compressive strength v/s % Fibre

30

34

38

42

46

50

54

2 4 6 8 10 12 14

% Fibre

Com

pres

sive

stre

ss N

/mm

² 40 mm50 mm60 mm

Fig: 4.2 Cube compressive strength of tested specimens: 7 Days


PRESIDENT’s MESSAGE

Dear Members,

It has been pleasure being President of ACCE for the tenure year 2007-2009.It gave averygood opportunity of meeting members at various centers during Govrnning Council meetings,seminars, technical meets or associated functions. It was always very warm welcome,greathospitality and very homely but very meticulously planned and executed programmes along withappropriate topics and technical contents. I enjoyed this term and will be cherished all along. I amthankfull to all of you for the cortsey extended to me.

Ensuing year is our silver jubilee year and we need to celebrate it in befitting manner.May beby holding technical meets,workshops,seminars,round table conference even places we do nothave centers. These location can be in the proximity of existing centers or in that region. The topicscan be of interest to suit considering requirments locally, regionally, nationally. I am of the opinionthat one issue which is of national importance is trainnig of personal involved such asdesigners,software for analysis,engineering,design,detailing,quantity survey etc. We also need tointeract, collabrate, cooperate with educational institutes, NGO, youngsters to upgrade knowledgeas well generate interest to learn and train to perform better.

Engineer Avinash Shirode, Nashik, is the President elect for the next term. He is a versitleperson and has been very actively involved not just on engineering proffession but on matter ofengineering societies. I am sure he will take ACCE (I) to much higher heights.

This will be the last bulletin in which I will be addressing as President. Hope to see all of you atDavangere for the AGM and installation of New Team.

Wishing you good bye and all the best in your profession.

UMESH B RAOPresident- ACCE(I)


Dr. M. N. HEGDEChairman, Bulletin Committee

Email: [email protected]

From the Editorial Desk

From Secretary General’s Desk

B. V. RAVINDRANATHSecretary General

Dear Members,

It is to inform you all that my term as Secretary General for last two years has come to an endmaking way for the new team and new Secretary General to take over for 2009-2011.

It is time to pay my tributes with thanks to the President, Governing Council Members and Staffat Head Quarters for extending their fullest support in conducting my term smoothly andsuccessfully. I wish to express my sincere thanks to all members for extending their supportduring my term. It was indeed a great time of my career to meet many senior members ofACCE(I), get their advice and guidance apart from visiting various places to further the activitiesof association. It was indeed an eye opener for me to know about the excellent brotherhoodexisting among our fraternity members. The opportunity to meet and hear lectures from doyensin our field and share platform with them was unforgettable one. The term also showed how anindividual can be part of an association for the greater causes of both.

With the new team set to take over at the AGM at Davangere, I wish them success in theirendeavors. I am hopeful to interact with you all in a different capacity under new team.

Looking forward to meet you all to thank you in person at AGM at Davangere.

Dear fellow members,

I tried my best to retain the standards of the bulletin. Unfortunately, I could not fulfilmy own expectations for the bulletin. I wish that the bulletin will soon be convertedinto a Journal.

I thank all members for their criticism, suggestions and support / encouragementduring last two years of publication of the bulletin. I also thank the members ofAdvisory and Editorial Committee for their valuable contribution and involvement. Ithank Mr. S. D. Anne Gowda, who always takes personal interest in the publicationof the bulletin. I take this opportunity to thank Mr. Ekambaram and Mr. Harish fortheir co-operation and assistance. I sincerely thank Mr. Sathishchandra for wonderfulDTP work and timely completion of the work.

I am grateful to President and Secretary General for their constant support &encouragement.

I wish next team all the success and wish that the bulletin will be taken to a newheight. I congratulate the new team under the leadership of Mr. Avinash Shirodeand Dr. M. U. Aswath, and wish them all the best.

With warm regards,


SLURRY INFILTRATED FIBROUS CONCRETE (SIFCON)-An Experimental Study

Dr. Aswath M.U., Professor in Civil Engineering, BIT, Bangalore-4 Sreenivas S.R., Consulting Engineer (Former PG Student BIT)

ABSTRACTSlurry infiltrated fibrous concrete SIFCON is a relativelynew high-performance and advanced material and canbe considered as a special type of steel fibre reinforcedconcrete (SFRC). SIFCON is a unique constructionmaterial possessing high strength as well as large ductilityand far excellent potential for structural applications,when accidental or abnormal loads are encounteredduring service. SIFCON also exhibit a new behavioralphenomenon, that of ‘fibre interlock’ which is believed tobe responsible for its outstanding stress-strain properties.

In this view an attempt has been made to study thebehavior of SIFCON in compression and tension. Total87 specimens were cast and tested. 57 cylinders and30 cubes with fibre length of 40mm, 50mm and60mmand with fibre percentages of 6, 8, and 12 wereinvestigated using super plasticizer to improve watercement ratio. In the present investigation the study oftensile and compressive behavior of SIFCON is done fordifferent variation in fibre percentage and fibre length.

Keywords: SIFCON, steel fibre, cylinders, cubes,compression testing, tensile strength, water cement ratio.

1.0 INTRODUCTIONThe technique of infiltrating layers of steel fibres withPortland cement based materials was first reported byHaynes [1968]. Lankard [1979] modified the methodused by Haynes and proved that if the percentage ofsteel fibres in a cement matrix could be increased, onecould get a material with very high strength propertieswhich he named as SIFCON. Later he extended theapplication of SIFCON to refractories [1982]. Theengineering properties of SIFCON along with a numberof successful applications were again investigated byLankard and Newell [1984]. Homrich and Naaman [1987]studied its stress strain properties in compression.Naaman [1987] also investigated the use of SIFCON inconnection with seismic resistance frames.Parameswaran et al [1990] investigated the behaviour ofSIFCON under impact, abrasion on flexural loads. Theyalso studied the feasibility of different ways of makingSIFCON and measured their relative toughnesscharacteristics [1991].

SIFCON has already been successfully used abroad forthe construction of structures subjected to impact, blast& dynamic loading and also for refractive applications,overlays and repairs of structural components because

of its high tensile strength and ductility. In the presentinvestigation compressive strength, Young’s modulus andPoisson’s ratio of SIFCON are studied. The tests wereconducted on specimen caste by SIFCON matrix withdifferent fibre volume contents.

2.0 OBJECTIVE AND SCOPE OFINVESTIGATIONFrom the literature study conducted, it appears that anumber of researchers were concentrated their attentionon the study of various strength properties with constantl/d ratio and varying percentage of volume of fibre. In thepresent investigation an effort has been made to studythe properties of SIFCON keeping both 1/d ratio andpercentage of volume of fibre as variables. Theexperimental investigation is related to compression splittensile and modulus of elasticity of slurry infiltrated fibrousconcrete. The cubes and cylinders of standarddimensions were cast and tested as per I.S.specifications after curing 7 & 28 days. In thisinvestigation the parameters adopted as constants arethe water cement ratio, diameter of steel fibre andcompaction (table compaction) period. The variedparameters are: 1.The aspect ratio (1/d) of the fibres(40, 50 and 60) 2.Percentage of fibre (6, 8 and 12)

3.0 TEST PROGRAMMEThe present experimental investigation focuses attentionon the compression and split behavior of slurry infiltratedfibrous concrete. Coarse aggregate has been replacedby the fibre in percentage of 6, 8 and 12 by total volumeof specimen. In all the mixes the water cement ratiowas kept constant (0.5) using super plasticizer (SP 337)at 7 ml/kg. The aspect ratios of fibre are 40, 50 and 60.Ordinary Portland cement is used in the experimentalwork.

The test program consists of carrying out compressivetests on cubes and cylinders, split tensile tests andmodulus of elasticity tests on cylinder. The total numberof specimens for all mix proportions is 87, which consistsof 30 cubes, and 57 cylinders. Each cube of size 150 x150 x 150 mm, cylinder of diameter 150 mm and length300 mm.

Each mix consists of 3 cubes and 6 cylinders for eachpercentage of fibre and for each aspect ratio of fibres.Thedetails of constant, variable parameters and specimendetails are as shown in below table.


Varied parameters Type of specimens

Constant parameters Length of fibre % ge of Cubes Cylindersvolume of fibre 15x15x15 cm 15x30 cm

W/c ratio = 0.5 40 mm 6 3 68 3 612 3 6

Compaction period 2 minutes 50 mm 6 3 6(Table Vibrator) 8 3 6

12 3 6

Dia. of fibre = 1 mm 60 mm 6 3 68 3 612 3 6

Plain mix (1:1.5:3) 0 3 3

4.0 EXPERIMENTAL INVESTIGATION ANDPRESENTATION OF TEST RESULTS4.1. GeneralAn experimental study is conducted on slurry infiltratedfibrous concrete (SIFCON). The design mix consists ofhigh strength slurry with various percentage of fibre byreplacing coarse aggregate. Cubes and cylindricalspecimens cast and tested for compressive strength,split tensile strength. Experimental study is carried outto investigate the strength variation in concrete byreplacing coarse aggregate by fibre and to find out thestrength properties of SIFCON.

4.2 Materials:Cement: Ordinary Portland cement of 43 gradeconforming to ISI standards. The cement is tested forits various properties as per IS 8112-1989. The resultsare Normal consistency is 30%, Initial setting time is45 minutes, Final setting time is 7 hours and Specificgravity is 3.08.

Fine Aggregate (Sand): River sand from the localsource. The specific gravity of the sand is 2.65 whereas its fineness modulus is found to be 2.99 confirmingto zone – II.

Water: The potable fresh water, which is free fromconcentration of acid and organic substances, is usedfor mixing the slurry.

Super Plasticizer: SP 337 super plasticizer at 7 ml/kgis used to improve water cement ratio.

Fibres: Black wire fibre of 1.0 mm diameter with ultimatetensile strength of 390 N/mm2 is used. The fibres arecut to required lengths using shear cutter. The fibre lengthof 40, 50 and 60 mm are used.

4.3. Fabrication and CastingThe cylinders were cast in steel moulds of diameter 150

mm and 300 height and the cubes are cast in steelmoulds of inner dimensions of 150 x 150 x 150 mm.

For all test specimen moulds are kept on table vibratorthe moulds are filled with fibre in random manner ofcalculated volume. For each percentage of fibre and foreach aspect ratio of fibres 3 cubes and 3 cylinders werecast. After placing the fibres in the moulds the slurrywas poured into the fibre bed and vibrations were effectedby table vibrator. The vibration was effected for 2 minutes,for each mould and it is maintained constant for all thespecimens.

4.4 Testing of specimensAfter curing the specimens in water for a period of 7 and28 days they were allowed to dry under shade and thenwhite washed. The specimens were tested forcompression and split tensile strength.

Compression Test: The test results are tabulated for 7and 28 days in table 4.2.and 4.3. The variations of thecube compressive strength for the three types of aspectratios versus volume percentage of fibres are shown infigures 4.2.and 4.3.

Split tensile strength test: The tensile strength ofconcrete is calculated using the formula 2P/ (3.14 D xL) where P=maximum load, L=length of cylinder and =diameter of cylinder.

Split tensile strengths for all cylinders tested werefurnished in the table no: 4.4. The variations of the splittensile strengths for the aspect ratio of fibres (40, 50,and 60) versus volume percentage of fibres are shown infig.4.4

Modulus of elasticity test: The typical stress stainrelations are shown in figures: 4.5 to 5.3. The modulusof elasticity was determined at 30% of ultimate strengthof cylindrical specimen. It was observed that the linearitybetween stress and strain exhibits up to 30% ultimate


strength. The modulus of elasticity values determined inthis investigation is furnished in table no: 4.5. The failureload was taken as cylindrical strength of the specimen.The modulus of elasticity is determined by taking initialtangent modulus for each percentage of fibre and for eachaspect ratio of the fibre.

4.5. General observations:It was observed in compression tests that the plainconcrete cubes failed suddenly in a brittle manner whereas the SIFCON cubes produced significant cracks withincrease in the post cracking strength.

In the case of cylinders it was observed the top andbottom surfaces of plain concrete cylinders were crushedwhere as in the SIFCON no such crushing was observedwhich is an indication of the ductility of slurry infiltratedfibrous concrete.

5.0 DISCUSSION OF TEST RESULTS5.1. Compression TestCylinders: Typical stress strain curves in compressionare presented in table 4.4. The SIFCON specimensbehave in a very ductile manner compared with planeconcrete (1:1.5:3) specimens. It may be observed thatthe energy absorption is more in SIFCON specimens.

The energy absorption effect can be achieved in twoways. One is increasing the fibre length by keepingvolume of fibre constant. The other one is by keepingthe fibre length constant and varying the percentage offibre.

From table 4.4 it may be observed that as the percentageof fibre increases the E value increases. The E value forSIFCON specimens is more compared with plain concretespecimens. This may be due to difference in matrix.The stress distribution is more effective in SIFCONspecimens.

Cubes: It was observed that the compressive strengtheffect is more with increasing the percentage of fibre forparticular l/d ratio. The compressive strength was isincreases by increasing the length of fibre by keepingvolume of fibre constant.

5.2. Split Tensile Test:From table 4.4 and figs4.4, it is evident that higher valueof tensile strength is obtained by increasing the fibrevolume with 1/d ratio as constant variable.

The higher split tensile strength may also be obtainedby increasing the fibre length with constant percentageof volume of fibre. But the increment rate is less in latercase.

6.0 CONCLUSIONSConclusions: From the limited tests conducted, thefollowing tentative conclusions can be drawn based onthe results presented. It should be noted that the results

pertain to the use of straight steel fibres.

• The higher compressive strength may be obtainedusing higher volume of fibre and 1/d ratio, providedwith good bond between matrixes.

• SIFCON exhibits extremely high ductility• An increase in fibre length leads to an increase in

both compressive strength and tensile strength.• At constant fibre length compressive strength is

directly proportional to the volume fraction of fibres.It may be noted that after a certain fibre loading thebond strength goes down because of lack of matrixpresence in between the fibres.

• The relation between compressive strength andtensile strength for different aspect ratios is linear.

Table 4.2 Cube compressive strength of testedspecimens: 7 DaysFor plain concrete (1:1.5:3) mix Compressive strength =46.67 N/mm2




1 6 92.5 40.5 100 44.3 111 49.82 8 95 42 102 45 113 50.33 12 99 43.5 111 48.3 119 54

Table 4.3 Cube compressive strength of testedspecimens: 28 DaysFor plain concrete (1:1.5:3) mix Compressive strength= 46.67 N/mm2




1. 6 104 46 108.5 48.5 116 51.52. 8 106 47 110 49 118 52.53. 12 112 49.5 114.5 51.5 125.5 55.5

Chart Compressive strength v/s % Fibre

30

34

38

42

46

50

54

2 4 6 8 10 12 14

% Fibre

Com

pres

sive

stre

ss N

/mm

² 40 mm50 mm60 mm

Fig: 4.2 Cube compressive strength of tested specimens: 7 Days


RETHINKING SUSTAINABILITY

In our earlier articles we have made a brief review of theinstitutional and technological solutions to the presentecological crisis and also their limitations. We have alsoindicated a third, evolutionary remedy as a more lastingsolution to the problem. This article presents a perspective,which can lead humanity safely and surely towards itssustainable future.Rethinking Nature The evolutionary agenda we will be presenting hererequires two basic cultural changes: rethinking Nature andrethinking Development. The first step has to be a rethinkingof our cultural attitudes to Nature. Ecological awareness is an inherent and inbuilt instinctin the ancient mind. It is a religious instinct based onreverence and worship of the sustaining source of their life.In some of the more mentally and spiritually advancedcultures like India and China, this ecological instinctdeveloped further into an aspiration to understand and livein conscious attunement with the laws and rhythms ofuniversal Nature. Modern ecology is only a partial recoveryof this ancient wisdom at the physical level. Partial because,in the ancient Indian and Chinese thought, Nature is notonly physical, but also psychological and spiritual. Man is apart of Nature not only physically but also psychologicallyand spiritually. Nature is not only our material Mother fromwho we draw all the physical energies needed for ourmaterial and economic development but also our eternaldivine Mother of the world who is the source of all energiesin Man and Universe, in all levels of existence-physical,psychological and spiritual. Each part or level of our humanorganism-physical, vital, mental and spiritual-derives itsenergy from the corresponding levels or planes of theCosmic Nature and is governed by its own unique set oflaws. Thus, there is a greater and a more integral ecologybeyond the ecology of the physical Nature which remainsyet to be explored. The aim of this integral ecology is toarrive at a holistic understanding of the laws of human anduniversal Nature in all the dimensions-material,psychological and spiritual-and explore their mutualinteractions, similarities, differences and correspondencesand their practical implications for human wellbeing andprogress. This cannot be done entirely by the scientific and rationalmind. We must have the spiritual intuition of the seer, sageand the mystic. If we don’t have it, we must have to drawupon the spiritual wisdom of the past and present and basedon it, use our rational, scientific and pragmatic mind to arriveat a flexible framework of thought and practice, action andapplication. So neither a superstitious reverence and worship nor anarrogant and heartless exploitation can be the right attitudeto Nature. The divine Teacher in the Indian scripture BhagvatGita gives the highest value to the “Knowing Lover”. So inour attitude to Nature we have to combine knowledge anddevotion, which means a synthesis of an aesthetic,

emotional and spiritual devotion to the divinity and beauty inNature and an understanding attunement and obedienceto the laws and purpose of Nature. So the attitude of modernecology, which is that of understanding and attunement, ispart of the spiritual attitude to Nature. But this understandinghas to be widened and deepened to embrace all thedimensions of Nature and it has to be synthesized with theattitude of the deeper heart of the artist, lover and devotee.One of the main causes of the present environment crisisfacing our modern civilization is the loss or lack of the senseof reverence and sacredness of Nature: As the Brazilianenvironmentalist Josi A. Lutzenberger states: “Most important and certainly most difficult of all is thenecessary rethinking of our cosmology. Theanthropocentric world-view westerners inherited from ourremote Judeo-Christian past has allowed our technocratsand bureaucrats and most simple people, too, to look atPlanet Earth as if it were no more than a free storehouse ofunlimited resource to be used, consumed and wasted foreven our most absurd or stupid whims. We have no respectfor creation. Nothing in nature is, nothing except us,humans, has sufficient inherent value—. Mountains canbe razed, rivers turned around, forest flooded or annihilated,unique life forms or whole living systems eliminated withoutqualms or patented for personal or institutional power.”(1) But mere thinking, understanding or “love” withoutcorresponding actions is ineffective for sustainabledevelopment. One of the positive features of the modernenvironmental movement is that it not only insists onawareness and understanding of the laws of Nature butalso emphasies that this awareness has to be translatedinto appropriate decisions and actions which help inpreserving the purity of the environment or in other words, Imust do whatever I can within my capacity to preserve theenvironment. For example if I say I am a lover of Nature andtravel in a car which causes the highest pollution, then my“love” for nature is only an ignorant sentiment. If I am a truelover of Nature, I will buy a car only when it becomes a realneed. Before buying I will make an extensive research andenquiry to know which of the available car models or brandsare the most environment-friendly in terms of petrolconsumption and emission, and I will buy this model orbrand even if it costs a little more than other models. I willuse the car only for long-distance journey and for shortersojourns I will either walk or use a cycle. Similarly, as far aspossible, I will not use products which cause maximumdamage to the environment and I will not buy goods orservices of companies which are insensitive to theirecological responsibility. As the environmental activist AlanSasha Lithman points out: “What good is it, after all, to attend conferences orworkshops on global warming, the control of CO2 emissionson renewable energy systems, grasping the conceptuallevel of the problem, if we drive to those meetings in gas-guzzling dinosaurs?”(2)

M.S. Srinivasan, Research Associate at Sri Aurobindo Society, Puduchery.Email: [email protected]


Rethinking Development The second step is a rethinking of the aims and valuesof development. This rethinking is already happening ineconomics and in the environmental movement. One ofthe most forceful exponent of this new thinking ineconomics is the Swedish economists E. F.Schumacher. In his well-known and influential book“Small is Beautiful” Schumacher presents a powerfulcritique of the traditional paradigms of development basedon endless material growth and consumption. He callsmodern humanity to return to the eternal values of truth,beauty and goodness and to Buddhist economics whichaims at “maximum well-being with minimumconsumption” and a work-culture where there is less toilfor acquiring more and more material wealth and as aresult “more time and strength is left for artisticcreativity”.(3) Commenting on the biblical passage “seek first thekingdom of God, all else will be added on to you”,Schumacher argues that the modern humanity, afflictedwith maladies like “terrorism, genocide, breakdown,pollution, exhaustion”, is in such a condition that “unlessyou seek first the kingdom of God, these other thinkswhich you need will cease to be available to you”. In theconcluding para of his book, Schumacher delivers thefollowing message to modern humanity: “The type of realism which behaves as if the good,the true, beautiful were too vague and subjective to beadapted as the highest aims of social and individual lifeor the automatic spin-offs of the successful pursuit ofwealth and power, has been aptly called ‘crak-potrealism’—People ask ‘What can I actually do’. Theanswer is as simple as it is disconcerting; we can eachof us, work to put our own inner house in order. Theguidance we need for this work cannot be found inscience or technology—but it can be found in thetraditional wisdom of mankind”.(4) In the field of Environment also some thinkers havecome to a more or less same conclusion asSchumacher. One of them is Dr. Maurice Strong, aformer chief of the UN Environmental Agency, who states: “We desperately need a new body of ideas, a newsynthesis. This must centre on the need for a newattitude towards growth—. It will require a major transitionto a less physical kind of growth, relatively lessdemanding of energy and raw materials. It will be one,which is based on an increasing degree on thesatisfaction of people’s intellectual, moral and spiritualneeds and aspirations in such fields as culture, music,art, literature and other forms of individual self-development and fulfillment. These are the areas in whichman can achieve his highest level of growth in humanterms” (5) Interestingly Sri Aurobindo, looking at human evolutionfrom a deeper and broader spiritual perspective had cometo a similar conclusion when he wrote in one of his earlywritings: “In the next great stage of human progress, itis not a material, but a spiritual, moral and psychicadvance that has to be made” (6) or in other wordsDevelopment of Consciousness. If this view is accepted,

then the future of sustainable development lies not ineconomics, technology or even in ecology but in appliedpsychology and spirituality, which will lead to the moralpsychological and spiritual development of humanity.This means priorities of sustainable development has toshift from material, economic and ecological sustainabilityto psychological and spiritual sustainability. This willnot be difficult because there is a much greater affinitybetween ecology and spirituality than between ecologyand economics. Ecology and inner development can bea mutually reinforcing combination. Inner development in the psychological and spiritualdomain can lead to a deeper and inner communion withNature, which in turn can bring a deeper suprascientificinsight into the physical as well as the supraphysicaldimensions of Nature. Similarly, a disinterested pursuitof the study of ecology or the ecological paradigm inthought, feeling and action can lead to an inner contactwith the universal intelligence or consciousness behindphysical Nature, which can open the doors to spiritualconsciousness. And the modern science of ecologyhave discovered two great spiritual principles at thephysical level. First is the unity of Man and Nature, andsecond is the connectedness and the interdependenceof human life. If the outer life of humanity is organisedaccording to these principles, with a clear understandingof the moral and practical implications of these principles,then it will create a favourable outer environment for theinner, moral and spiritual development of humanity. Letus now briefly summarise the positive consequences ofthis inner development for arriving at an enduring solutionto the ecological and economic problems confrontingour planet.Benefits of the Evolutionary Paradigm: As the human consciousness grows inwardly andfeels more and more the deeper and purer joy of innerfulfillment it will act against the desire for a gross externalfulfillment through an increasing material consumption.When I am inwardly fulfilled I don’t buy whatever I canafford nor do I crave for what I don’t have. I buy only whatI need and the rest of my earning I spend either for myinner growth or give it for the realisation of a higher idealwhich I believe will lead to a greater well-being of thecommunity or humanity as a whole. Similarly as wegrow in our mental, moral, aesthetic consciousness wewill feel an enlightened and spontaneous sense ofecological and social responsibility based not only onthe scientific understanding of the ecology of Nature butflowing from an emotional empathy and aesthetic feelingfor Nature, life and people around us. As we grow into the deeper and inner layers of ourpsychological and spiritual being it will activate in usintuitive faculties of consciousness beyond the scientificand rational mind. This will reveal to us the deeper andhigher psychological and spiritual dimensions of Natureand their laws and process, which the scientific andrational mind cannot perceive. In fact, even in the domainof material nature, can the modern scientific mind say itknows fully the totality of physical Nature? For example

Continued on page 16


The New Lightweight Structure TensairityLuchsinger, Dr. Rolf H.; Crettol, René and Plagianakos Dr. Theofanis S.

INTRODUCTIONFabrics structures have gained a lot of interest inarchitecture during the last decades. This interest ismainly based on the consequent light-weight approachof these structures, where the loads are solely carriedby forces in the plane of the membrane. As aconsequence, form follows functions in fabric structuresand the typical anticlastic shape of tensioned membranestructures results. Typical applications of fabrics inarchitecture are roof structures ranging from smallcanopies to coverings of huge stadiums.

A special class of fabric structures are pneumaticstructures, where the fabric is pretensioned by aninternal overpressure of the air. Airhouses used e.g. asseasonal coverings of tennis courts are examples forthese synclastic structures. In airhouses, the wholecovered volume is under an air overpressure in the orderof a few millibar. While airhouses can hardly be beatenin terms of light-weight, the basically spherical

or cylindrical shape leads to huge covered volumes whichoften cannot be used in an efficient way. Specialentrances are a must in order to maintain the overpressure. The often tremendous power supply for aircirculation, pressure sustainability and heating andprobably also the psychological barrier of beingimprisoned in an airtight structure have limited theapplication of airhouses to niches.

However, pneumatic structures can also be used as beamelements. While such airbeams are applied in small tentse.g. for emergency situations, these interesting light-weight structures have with a few exceptions not beenused for larger structures in architecture and civilengineering. One of the main reasons is the very restrictedload bearing capacity of such airbeams. The newstructural concept Tensairity combines an airbeam withcables and struts to yield a girder with a load bearingcapacity comparable to conventional structures.

THE NEW LIGHTWEIGHT STRUCTURETENSAIRITYThe Tensairity technology was developed by the companyAirlight Ltd. in close collaboration with prospectiveconcepts ag (1-4). Recently, the Tensairity activities ofprospective concepts were transferred to the new Centerfor Synergetic Structures, a public private partnershipbetween Empa and Festo. Empa is a transdisciplinaryresearch institution within the ETH Domain with a majorfocus on materials science and technology development.Festo is a leading company in automation pneumatics.To strengthen the R&D of synergetic structuresespecially of Tensairity structures is the main objective

of this center.

The fundamental Tensairity beam consists of a cylindricalairbeam, a compression strut tightly connected with theairbeam and two cables spiraled around the airbeam andattached at each end with the compression strut (Fig.1). While the cables are pretensioned by the airbeam,the buckling problem in the compression strut is avoideddue to the stabilization by the airbeam. As for a beamon an elastic foundation, the buckling load in thecompression strut of the Tensairity girder is independentof its length but relies on the pressure in the airbeam(1,3). Since there is buckling free compression inTensairity, the cross section of the compression strutcan have minimal dimensions leading to the light weightproperty of the new structural concept. Furthermore, thepressure in the airbeam is solely determined by the loadper area on the structure and independent of the spanand slenderness of the beam (1). Therefore, thesynergetic combination of an airbeam with cables andstruts has a great potential for wide span structures.

APPLICATIONS OF TENSAIRITYIn recent years, various first applications of Tensairityhave been realized. Probably the most impressive oneis the roof for a parking garage in Montreux, Switzerland.While the cylindrical shape was the first Tensairity forminvestigated (Fig. 1), further studies have revealed, thatspindle shaped Tensairity girders are more efficient (2,3) and applications such as the roof over the parkinggarage in Montreux (Fig. 2) rely on the spindle shape.This membrane roof is supported by 12 Tensairity girderswith a span up to 28 m. Steel has been used for theupper and lower chord of the Tensairity girder. The samesilicon coated glass fiber fabric is used for the coveringas well as for the Tensairity girders. The air pressure inthe beams is about 100 mbar. Intensive

use of the intriguing lightning possibilities of Tensairitywas made by the architects in the roof in Montreux.Spotlights with color changing capabilities are mountedon each end of the Tensairity beams. The light shinesthrough glassy end plates into the pneumatic structureand illuminates the Tensairity girders from inside in asurprisingly homogeneous way. The color of eachTensairity beam can be dynamically changed andcontrolled by software enabling interesting light patternsover the whole roof structure.

Two years ago, a skier bridge in the French Alps with aspan of 52 m supported by two asymmetric spindleshaped Tensairity girders was completed (Fig. 3). Thecompression element of this structure is made of wood,while the tension element is made of steel. During the


winter season, a ski slope runs over the bridge. The deckis covered with a thick layer of snow leading to highloads. This bridge is an impressive demonstration of thepotential of Tensairity for wide span structures with heavyloads.

While the structures of the foregoing examples rely onTensairity-beams, the Tensairity concept can also beused for shell-like structures. An example for thisapproach is a canopy in Pieterlen, Switzerland (Fig. 4,left). Two grids of steel profiles form the upper and lowerlayer of the structure. The grids of the two layers areconnected by tension elements in order to preserve thethickness of the structure under inflation. An upper andlower fabric layer maintains the structure airtight. Theair-pressure pretensions the fabric and stabilizes the twometal grids. As there is essentially only air inside thestructure, light is used to enhance the optical appearanceof the canopy during night. It is possible to look througha glass window inside the structure from the stairs ofthe building. A special landscape showing the tensionconnections between the upper and lower layer as wellas the fabric bulging between the steel grid can be seen(Fig. 4, right).

Another realized application of Tensairity is anadvertisement pillar. Next to the load bearing capacity,the most important properties of this structural conceptare small transport and storage volume as well as fastset up and dismantling. Setting up a Tensairity beamcan be as simple as connecting the compression elementwith the fabric and cables followed by blowing up thestructure. This feature was used in a Tensairityadvertisement pillar prototype which had a height of 20m and could withstand wind speeds up to 100 km/hwithout any bracing. These advertisement pillars can beused for mobile marketing, e.g. at fairs, open-air festivalsor sport events. A further application of Tensairity is anexhibition stand for a Swiss watch manufacturer whichwas partly built by cylindrical Tensairity-girders. Thestructure supported a hanging platform for visitors wherea sports wagon was exhibited. The advertisement pillarand the exhibition stand show, that Tensairity is aninteresting concept for temporary structures.

These realized applications are the best demonstrationof the potential and reliability of Tensairity. Thetechnology can support heavy loads at wide span asshown with the skier bridge. Tensairity implies a newformal language. It has intriguing lighting options and iswell suited for temporary structures. On top of that,Tensairity structures float on water. Filled with heliumthey can under certain conditions be even lighter thanair. And Tensairity structures are adaptive (5). So themost outstanding feature of Tensairity is probably notany of this property but the sum of all: Tensairity is ahighly multifunctional structure. Thus for applicationswhere not only a single

aspect as e.g. the weight matters, but weight plus designplus being temporary, for these applications Tensairitycan offer a new and unique solution.

TENSAIRITY RESEARCHResearch and development of the Tensairity-concept isthe main task of the Center for Synergetic Structures.The interactions between the compressed air, the fabric,the tension element and the compression element needto be very well understood. At the moment, the focus ofthe research is on spindle shaped Tensairity-girders sincethey are stiffer compared to cylindrical girders (2). In arecent paper, the deformation behavior of Tensairity-girders under local bending load was investigatedexperimentally and compared to numerical studies (6).The qualitative behavior of the Tensairity spindle can bereproduced with FEM calculations, where the membraneis treated as a linear isotropic material. The forces atthe center of the tension and compression chord of theTensairity spindle are shown to be a linear function ofthe applied load. They are to a very good approximationindependent of the air pressure and reasonablyapproximated by the FEM calculations and by a simpleanalytical model. The work further reveals the interestingload-displacement response under a local centralbending load. However, while the comparison of the load-displacement response between FEM calculation andexperiment is good at the compression side, thenumerical study predicts a significantly lower deflectionat the tension side compared to the measurement. Thismight be addressed to the crude membrane materialmodel in the FEM calculation.

An important result of this work was that the behavior ofa Tensairity girder is much more complicated than e.g.the behavior of a truss. The deflection is not onlydetermined by the structural set-up and the load but alsoby the variable air pressure. The displacements of theupper and lower chord are considerably different.Therefore, one has to be specific when talking aboutdeformation of Tensairity girders. Due to the fabric part,the Tensairity girder shows an initial hysteretic behaviorwhich is different from later load cycles. The fabric is anon-linear, orthotropic material with history dependentproperties. These properties have an influence on thewhole Tensairity structure.

The in-depth investigation of the characteristics of thefabric including the shear modulus is one focus of thecurrent research of the Center for Synergetic Structures.For the study of the deformation behavior of Tensairitygirders, two test rigs have been set up at Empa. In onetest rig the deformation behavior of spindle shapedTensairity girders under homogeneously distributed loadis experimentally investigated in collaboration with ETHZürich. In this test rig, girders with up to 10 m span canbe investigated. In the second test rig, the first


experimental studies of the behavior of spindle shapedTensairity girders under axial compressive loads are inprogress. The test girder has a length of 5 m and amaximal diameter of 0.5m. It consists of an inflated textilemembrane hull and three struts placed at respectiveangles of .=120° along the section. The struts areconnected at both ends with cylindrical end fittings. Eachstrut is made of Aluminum, has a rectangular crosssection (30x10 mm2) and is placed in pockets sewedupon the hull. The material of the membrane is apolyamide based fabric (Dynatec/Schoeller) with anembedded PU foil to keep the structure air tight. Anexperimental load-displacement diagram at the point ofload application for air pressure values of 150 mbar and300 mbar is shown in

Figure 5 (7). A load up to 10 kN was applied. After aninitial deformation of about 1 mm, the deformationincreases as an almost linear function of the appliedload. Obviously, the structure with the higher pressureis stiffer, although the difference is only in the order of aquarter millimeter. This means that the three struts ofthe Tensairity spindle are very well stabilized andpositioned by the pretensioned fabric at these pressurevalues. For very low pressure values the structurebecomes very soft. The stabilization trough air pressureis therefore very important in these columns. Furtherinvestigations are in progress to scrutinize this promisingbehavior of Tensairity columns.

CONCLUSIONSThe new structural concept Tensairity is a synergeticcombination of an air beam with cables and struts. Theloads are carried by the cables and struts. The role ofthe air beam is to stabilize the structure. This light-weightstructure has a range of interesting properties and canbe ideally used for temporary structures. Firstapplications as roof structures, a bridge, anadvertisement pillar or an exhibition stand demonstratethe potential and reliability of the structural concept. Inparallel to these applications, the basic concepts ofTensairity need to be better understand. Experimentaland numerical studies of the Center for SynergeticStructures enlighten the role of the fabric in Tensairity-girders and reveal the potential for Tensairity columns.All these efforts will allow to develop the full potential ofthis interesting technology.

AFFILIATIONLuchsinger, Dr. R. H.: Empa, Center for SynergeticStructures, Ueberlandstrasse 129, CH-8600 Dübendorf,Switzerland, [email protected]

Crettol, R.: Empa, Center for Synergetic Structures,Ueberlandstrasse 129, CH-8600 Dübendorf, Switzerland,[email protected]

Plagianakos, Dr. T. S.: Empa, Center for Synergetic

Structures, Ueberlandstrasse 129, CH-8600 Dübendorf,Switzerland, [email protected]

REFERENCES1. Rolf H. Luchsinger, A. Pedretti, P. Steingruber and

M. Pedretti, “The new structural concept Tensairity:Basic Principles”, in: A. Zingoni, (ed.), Progress inStructural Engineering, Mechanics and Computation,A.A. Balkema Publishers, London, 2004, p. 65

2. Andrea Pedretti, P. Steingruber, M. Pedretti and R.H.Luchsinger, “The new structural concept Tensairity:FE-modeling and applications”, in: A. Zingoni, (ed.),Progress in Structural Engineering, Mechanics andComputation, A.A. Balkema Publishers, London,2004, p. 66

3. Rolf H. Luchsinger, A. Pedretti, P. Steingruber andM. Pedretti, “Light weight structures with Tensairity”,in: R. Motro, (ed.), Shell and Spacial Structures fromModels to Realization, Editions de l’Espérou,Montpellier, 2004, pp. 80-81

4. Rolf H. Luchsinger, R. Crettol, P. Steingruber, A.Pedretti and M. Pedretti, “Going strong: Frominflatable structures to Tensairity”, in: E. Onate andB. Kröplin, (eds.), Textile Composites and InflatableStructures II, CIMNE, Barcelona, 2005, pp. 414-420

5. Rolf H. Luchsinger and R. Crettol, “AdaptableTensairity”, in F. Scheublin, A. Pronk, A. Borgardand R. Houtman (eds.), Adaptables’06, Proceedingsof the joint CIB, Tensinet and AISS internationalconference on adaptability in design andconstruction, Eindhoven, 2006, pp. 5.3-5.7

6. Rolf H. Luchsinger and R. Crettol, “Experimentaland numerical study of spindle shaped Tensairitygirders”, International Journal of Space Structures,Vol. 21/3, 2006, pp. 119-130

7. Theofanis S. Plagianakos, R. H. Luchsinger and R.Crettol, “Deformation of spindle shaped Tensairitycolumns under compression”, Proceedings ofCOMP_07: 6th International Symposium on AdvancedComposite Technologies, Corfu, GR, 2007


does it know fully what are the ecological consequencesof splitting an atom or slicing or altering a gene? No truescientific mind will be so arrogant to make such astatement. As we ascend into the deeper and higherlevels and acquire new intuitive faculties we will get amore total and holistic insight into unity, harmony andinterdependence of life and Nature and as a result, betterunderstanding of the consequences of our decisions andaction. When the scientific, technological, professionaland managerial mind of humanity acquires these higherintuitive faculties beyond the scientific and the rationalmind, many of the problems related to environment,energy, economics or development, will find a quickerand better solution.

And finally when the human consciousness growsmore and more into the unity-consciousness of the spirit,in which we can feel our oneness with all existence, itwill lead to an unprecedented levels of cooperation andharmony among humanity. And no problem, in whateverdomain it may be, can stand against the harmoniousand focused assault of the creative energy of the humanspirit. The spiritual intuition will also reveal the deepestand highest spiritual truths of Man, Nature and God intheir perfect unity and harmony. This will lead to arediscovery of the ancient wisdom which saw and adoredNature as a living Goddess and the divine Mother of usall and an altogether new paradigm of spiritual ecology.

The Path to Sustainable Evolution This brings us to the pragmatic question: how toachieve this higher evolution? The path involves threesteps. First of all we have to evolve a synthesis of thespiritual wisdom of humanity with the modern secularvalues of liberal humanism, science, ecology andenvironmentalism. Second is to build an outer economic,social and political organisation based on this synthesis.Third, and the most important, is a system of education,which can internalise the values of this synthesis in theconsciousness of the people. This cannot be doneentirely by the present system of mental education. Wehave to evolve a new systems of education by whichhigher values like Unity of Man and Nature are not merelythought and felt as an idea or sentiment but becomeconcrete experiential realities of consciousness, felt asconcretely as we feel our body. There is a system ofknowledge or science, which can provide the basis forsuch an experiential education. It is the ancient Indianscience of Yoga.References:1. Josi A. Lutzenberg, NGO as a Driving Force, ed. Fritjof Capra

and Guntur Pauli, Steering Business Towards sustainability,p.32

2. Alan Sasha Lithman, Evolutionary Agenda for the ThirdMillenium, pp.125

3. E.F. Schumaker, Small is Beautiful, pp.44-524. ibid, pp.2505. Maurice Strong, New Growth Model, Future of a Troubled

World, Ed, Richie Caulder. pp.141

Continued from page 12

Courtesy : SEWC 2007


Review and Design of Flat Plate/Slabs Construction in IndiaGowda N Bharath; Gowda S. B. Ravishankar; A.V Chandrashekar

ABSTRACTThe objective of this paper is to present the use offlat plate/slab construction in India. The paper beginswith an introduction to flat plate/slab structures andtheir applications in buildings fol lowed by acomparative description of flat plate/slab structuredesigns based on Indian Standard IS 456:2000 andAmerican Concrete Institute ACI-318 codes. Thepaper also describes seismic design provisions perIndian Standard IS 1893 and Uniform Building CodeUBC 2000 for the lateral force design of flat plate/slabs. We conclude the paper by presenting two realworld construction projects designed by us inBangalore.

The discussion of the two construction projects willinclude a cost and structural efficiency review of theoriginal Post-Tensioned (PT) slab proposed for thoseprojects. Our review indicated a 15-20% higher costfor post-tensioned system when compared toconventional Reinforce Cement Concrete (RCC) andhence, conventional RCC structure was proposed forthose projects. Further, we have generally observedthat that there is no reduction in thickness of the slabwith post tensioned flat plate construction inBangalore (buil t by post tensioned concretecontractors) when compared to conventional RCC.Also, we have observed that many of the usualadvantages of using PT systems over conventionalRCC including a nearly crack free slab at service loadleading to smaller deflection and watertight structuresare absent.

INTRODUCTIONFlat plate/slabs are economical since they have nobeams and hence can reduce the floor height by 10-15%. Further the formwork is simpler and structureis elegant. Hence flat plate/slab construction hasbeen in practice in the west for a long time. However,the technology has seen large-scale use only in thelast decade and is one of the rapidly developingtechnologies in the Indian building industry today.Material advances in concrete quality available forconstruction, improvement in quality of construction;easier design and numerical techniques hascontributed to the rapid growth of the technology inIndia.

DESIGN OF THE FLAT SLABSTRUCTURESDespite the rapid growth of f lat plate/slabconstruction, literature and tools available fordesigners to design and engineer flat plate/slabs in

India, has been limited in terms of both Indianstandards and Indian research papers. Indianengineers often have to resort to other standards todesign flat plate/slab. The following is a discussionof the process of designing flat plate/slabs to meetIndian codes. Limitations in the Indian codes IS456:2000 are overcome by utilizing ACI-318.

The design of flat slab structures involves threesteps:1) Framing system2) Engineering analysis3) Reinforcement design and detailing

Framing System:Initial framing system formulation provides a detailedgeometric description of the column spacing andoverhang. Even though the architect provides this partof the design, the engineer should emphasize on thefollowing:

1) Three continuous spans in each direction or havean overhang at least one-forth times adjacentspan length in case of only two continuousspans.

2) Typical panel must be rectangular3) The spans must be similar in length i.e. adjacent

span in each direction must not differ in lengthby one-third.

Engineering Analysis:Flat plate/slab may be analyzed and designed by anymethod as long as they satisfy the strength, stiffnessand stability requirements of the IS 456:2000 or ACI-318 codes. A typical flat plate/slab can be analyzedby direct design method or equivalent frame methodas prescribed by the code. However, if the flat plate/slab is atypical with unusual geometry, with irregularcolumn spacing, or with big opening then the designermay have to use finite element method model analysisusing computers.

The design of flat plate/slabs irrespective of themethodology used must first assume a minimum slaband drop thickness and a minimum column dimensionto ensure adequate stiffness of the system to controldeflection. The IS 456:2000 code is not clear on theseminimums. However ACI specifies empirical formulasto arrive at these minimums. Refer to Table 1 forminimum slab thickness.

Once the slab thickness and column dimensions withboundary conditions are selected, the structure isloaded for different load cases and combinationsprescribed by the code. The computed forces and


moments in the members should be used forreinforcement design. Critical reactions for the loadcombinations are used for the design of the supportingcolumns and foundations.

ComputersDue to availability of software and high speed and costefficient computers, analysis-using computers is themost commonly used method to analyze flat plate/slab today. However the designer should be wellversed with all the theoretical methods to verifycomputer results.

To verify computer results like shear force and bendingmoment, the designer could compute shear at thevicinity of column by multiplying the total vertical weighttimes the tributary area supported by the column plusadditional vertical shear produced by unbalancedmoment at plane punching shear at column. Tocompute moments, the designer could use the directdesign method. Even though this method haslimitations, it is a reliable method to verify computerresults. Direct design method is essentially a threestep procedure: 1) determine the total moment for eachspan, 2) divide the total moment between negativeand positive moment within each span, and 3)distribute the negative and positive moment to thecolumn strip (half of span under consideration) andmiddle strip (half of the span under consideration)within each span. For convenience, the designer canuse moment coefficient in Table 2.

DeflectionComputing deflection of flat plate/slab is complicateddue to many parameters involved in the evaluation,such as aspect ratio of panels, stiffness effect of dropand column capital, lateral deflection of end columns,cracking and long term loading effects etc. IS456:2000 prescribes allowable deflection for slabs butis unclear about the actual computation of deflectionfor flat plate/slabs. Hence the designer has to refer tothe ACI-318 equivalent frame method to computedeflection or use computer analysis. The maximumelastic displacement of the structure results includingthe long-term effects due to creep and shrinkage isused to compare against the allowable deflection perthe appropriate code. Long-term deflection can becomputed per IS 456:2000 or ACI-319, but a simplerestimation is to use two times the elastic deflection.

Reinforcement Design and DetailingReinforcement design is one of the critical parts offlat plate/slab design; maximum forces from theanalysis shal l be used in the design of thereinforcement. Reinforcement required for flexure byusing minimum slab thickness per table 1 typicallywill not require compression reinforcement. Thetension steel area required and detailing for appropriate

strips can be per IS 456:2000 or ACI-318, both beingsimilar. However design for punching shear force(including additional shear due to unbalancedmoment) per IS 456:2000 is 32% conservativecompared to ACI-318, because Indian codeunderestimates the concrete two-way shear strengthby 32% compared to ACI.

Seismic Design of Flat plate/slabSeismic design lateral force is based on the provisionsof Indian Standard IS 1893 (Criteria for EarthquakeResistant Design of Structure), however due to non-clarity of IS1893 designer, in addition may have touse, other codes like UBC-2000 (Uniform BuildingCode) to design an effective lateral system. Basedon these codes a common practice is to determinelateral force by either using static or a dynamicprocedure.

Once the lateral forces are found, Flat plat/slabstructures in areas of low seismicity (Zone1& 2) canbe designed as permitted by code to resist bothvertical and lateral loads. However for areas of highseismicity (Zone3, 4 & 5) code does not permit flatslab construction to resist earthquake lateral load,hence lateral load resisting system has to de designedseparately in addition to flat plat/slab gravity system.The ability of flat plat/slab gravity system to supportvertical load when subjected to lateral load should bechecked (deformation compatibility check).

Flat Plate/slab floor slabs are typically consideredas a rigidity diaphragm to distribute in plane lateralloads to the lateral load resisting system. In case offlat plat/slab resisting lateral loads, floor slab willtransfer lateral loads at each column and thereforeall slab column connections should be checked foradditional force resulting from lateral loads. In addition,all columns should be checked for additional bendingresulting from lateral shear. When flat slab is used incombination with shear walls for lateral loadresistance, the columns can be designed for only 25%of the design force.

Post-Tensioned Flat Plate/slabPost-tensioned flat plat/slabs are a common variationof the conventional plate structure where most of thereinforcement is replaced by post-tensioned strandsof very high strength steel. The structural advantageof post tensioning over conventional RCC is that theslab is nearly crack-free at full service load. This leadsto a smaller deflection compared to conventional RCCbecause of the higher rigidity of the un-crackedsection. Hence reduction in thickness of the slabcompared to conventional RCC is the rationale forusing post-tensioning system for spans over 10m andabove. Further the lack of cracking leads to awatertight structure. Flat plat/slab design and build


contractors in India claim a 20% cost reductioncompared to conventional RCC.

However, our observation of post-tensioned flat plat/slab constructions used in two construction projects(see figure 1) in Bangalore built by post tensionedconcrete contractors utilizing PT system has beenthat there is no reduction in thickness of the slabcompared to conventional RCC and the slabs are notcrack free at service loads. Hence, the actualdeflection in these structures is similar to that oftheoretically computed RCC deflection. In addition,water tightness was not achieved in one of theprojects. And with respect to costs involved, there isan escalation in cost by 15-20% rather than reductionas claimed by PT design & build contractor.

And another disadvantage in using post tensionedsystem in commercial buildings in India, is its lack offlexibility to create openings or drill into slabs to anchorservices system when the slab is completed with posttensioning. Invariable the owner in India is not sure ofthe occupant when he starts the building and mayhave to change or create opening in slabs afterconstruction to satisfied occupants requirement, whichis not possible with a PT system.

PROJECT APPLICATIONWe have successfully used the above briefed methodin design of two projects namely Maas-3 and RPS.The Maas-3 project has been completed successfullyand is ready for occupation. The RPS project iscurrently under construction.

Project- Maas-3The building is a trapezoid in plan with an approximatedimension of 90 m length, 30M width and 15meterheight. The structure consists of basement car parkingfloor plus 4 upper office floors and terrace (figure 2).The structural system is a flat plate supported byregularly spaced vertical concrete columns, andfoundation for columns are typical concrete spreadfooting. Since the project is located in Bangalore(Zone-2), framing system would resist both lateral andvertical loads.

The design criteria are based on IS 456-2000 IS 1893Part 1 and IS 875 Part 3. The vertical loading iscomprised of the estimated self-weight, miscellaneousdead loads, and live load. The lateral loading iscomprised of wind and seismic loads. Due to irregularnature of the floor plan, the analysis of the structurewas carried out using computer and results wereverified by direct design methods and equivalent framemethod. Our hand calculations were very similar tothe computer-generated results. Originally we hadproposed post-tensioned PT slab for this project.However, due to observations of PT systems

mentioned above and our conventional RCC designyielding a cost reduction of 20%, prompted us todecide the use of conventional RCC flat slab as ourfinal design choice (figure 3).

Project- RPS commercialThe building is a rectangle in plan with approximatedimension of 50m length, 25m width, and with samefloors and height as the previous project, but the floorplan has only two bays hence appropriate 2.4moverhang was proposed on either side of the bay tomake it structurally efficient (figure 4&5).

FINAL REMARKSFlat plate/slab construction is a developing technologyin India. Flat plate/slab can be designed and builteither by conventional RCC or Post-tensioning.However, due to issues mentioned above with PTconstruction in India and its higher cost, conventionalRCC should be the preferred choice for spans up to10 meters. Design of conventional RCC flat plate/slabin India, ut i l iz ing Indian codes, has manyshortcomings, which have to be addressed andrevised soon. Until then Indian engineers will continueto use Indian codes in combination with otherstandards like the ACI, BS or Euro Code to designand analyze Flat slabs/plates.

Reference:1. Indian Standard IS 456:2000, Plain and Reinforced

Concrete Code of Practice.2. Purushothaman P., Reinforced Concrete Structural

Elements, Tata McGraw-Hill Publication CompanyLtd. New Delhi. 1984

3. Verghese P.C., Advanced Reinforced ConcreteDesign, Prentice-Hall of (India Private Ltd. NewDelhi. 2003

4. Notes on ACI 318-2000, Building Code RequirementFor Reinforced Concrete, Portland cementassociation. USA 2000

5. Structural Design Guide to the ACI Building code,Third edition, Van Nostrand Reinhold Company.New York. 1985

6. Kenneth Leet and Dionisio Bernal, ReinforcedConcrete Design, Third edition, McGraw-Hill, USA.1997

7. Structural Engineering Handbook, Forth Edition,McGraw-Hill, USA1997

8. Alaa G. S. and Walter H.D., Analysis and Deflectionof Reinforced Concrete Flat Slabs, CanadianJournal of Civil Engineering, Vol. 25. 1998

9. Branson, D.E, Deformation of Concrete Structures,McGraw-Hill Company, New York.1977

10. Nilson A.H. and Walter D.B., Deflection of Two-way Floor Systems by the Equivalent FrameMethod, ACI Journal, Vol. 72, No.5 1975


TALL SUSTAINABILITY—AN URBAN IMPERATIVEDr. M. N. Hegde, Faculty - Civil Engineering, Dr. AIT, Bangalore-560 056

Ancient tall buildings such as the Egyptian pyramidsand Mayan temples were primarily solid structuresserving as monuments rather than space enclosures.The modern tall buildings are conceived to serve as spaceenclosures providing required structural stability with achange in method of achieving the required structuralaction. They usually have freeform shape that fulfills thedual function of creating an exciting exterior and at thesame time provides interior spaces that are highlydesirable to lessees. The high rise building technologycan be thought of as a progressive reduction of materialsused within the space occupied by the building. For atall building to be successful, it has to satisfy concurrentlythe requirements of site, building program, and above allmake economic sense. From structural designconsiderations, a building can be considered tall whenthe effects of lateral loads are some way reflected in itsdesign. Lateral deflections of tall buildings due to windand earthquake loads should be limited to preventdamage to both structural and nonstructural elements.The accelerations at the top floors during frequent windstorms should be kept within acceptable limits tominimise discomfort to the building occupants.

Definition of Tall building: It is difficult to distinguishthe characteristics of a building which categorise it astall. The outward appearance of tallness is a relativematter. The definition of the world’s tallest building orthe world’s tallest tower is not very clear. The disputesgenerally centre on what should be counted as a buildingor a tower, and what is being measured. In a typicalsingle storey area, a five storey building will appear tall.Tall building can not be defined in specific terms relatedto height or number of floors. There is no consensus onwhat constitutes a tall building or at what magic height,number of stories, or proportion a building can be calledtall. The bottom line is where the design of the structuremoves from the field of statics into the field of structuraldynamics. The structure can be considered as tall whenthe sway or drift caused by lateral loads affects thestructural analysis and design. Here sway or drift is themagnitude of the lateral displacement at the top of thebuilding relative to its base (Ref: Taranath, 1988). As thebuilding heights increase, the forces of nature begin todominate the structural system and take on increasingimportance in the overall building system. Structuralsystems have to be developed around the conceptsassociated entirely with resistance to turbulent wind.

In contrast to vertical load, lateral load effects on buildingsare quite variable and increase rapidly with increase inheight. Other things being equal, overturning moment atthe base of a building varies in proportion to the square

of the height of the building under wind load, and lateraldeflection varies as the fourth power of the height of thebuilding. In the design of tall building, the structuralsystem must meet strength, rigidity and stability factors.In the design of low-height structures strength is theimportant criteria, whereas as for high-rise structuresrigidity and stability requirements become moreimportant and dominant factors in the design. Increasingthe size of the members above strength requirements,to meet these two requirements leads to uneconomicaldesign or may become impractical. The other importantapproach is to change in form of the structure into morerigid and stable to confine the deformation and increasestability. Under the action of wind, a tall building will reacha state of collapse by the so-called P-D effect, in whichthe eccentricity of the gravity load increases to such amagnitude that it brings about the collapse of the columnsas a result of axial loads. In tall, slender, and flexiblebuildings, dynamic loads are induced by the buffetingaction of atmospheric turbulence.

Important stability criteria:

• Assure that predicted wind loads will be below theload corresponding to the stability limit.

• Limit the lateral deflection to a level that will ensurethat architectural finishes and partitions are notdamaged.

• The interstorey drift (the floor-to-floor deflection) hasto be limited to minimise the damage.

• Slender high-rise buildings should be designed toresist the dynamic effects of vortex shedding byadjusting the stiffness and other properties of thestructure such that the frequency of vortex sheddingdoes not equal the natural frequency of the structure.

• Lateral deflections of the buildings should beconsidered from the stand points of serviceabilityand comfort.

• The peak accelaerations at the top floors of thebuilding resulting from frequent wind storms shouldbe limited to minimise possible perception of motionby the occupants.

• In earthquake resistant design, it is necessary toprevent outright collapse of buildings under severeearthquakes. Limit the nonstructural damage to aminimum.

• Designed to have a reserve ductility to undergo largedeformations during severe earthquakes.

• If the structure needs to be designed for gravity loadsonly, the stresses caused by lateral loads willautomatically be limited to the 33 percent overstressallowed in most codes.


The material quantities needed with reinforced concretebuildings also increase as the number of storiesincreases. The increase in material for gravity load ismore than for steel buildings, whereas the additionalmaterial required for lateral load is not high for steelbuildings, since weight of additional gravity loads helpsto resist the lateral deflection and overturning moment.The additional gravity load, on the other hand, canaggravate the problem of designing for earthquake forces.

The graph shown in Figure 1 illustrates how unit weightof a structural material such as steel increases as thenumber of floors increases.

Figure 1. Structural Steel quantities for Gravity Load andWind Load systems (Source: Taranath, 1988)

The unit weight of structural framing members may bereduced with the application of• Innovative and state-of-the-art design concepts• Use of high-strength low-alloy steels,• Use of welding instead of bolting,• Increased use of composite construction, and light

weight aggregates• Application of computers for analysis and design,• gradual increase in the allowable stresses in the

material based on the research and pastperformance

• Reduction in other construction materials andequipments

The cost of structure usually accounts for 20-30% of thecost of a tall building. The cost of wind bracing systemmay work out to one-third of the structural cost (or almost7-10% of total cost). Each building, of course, is aresponse to a unique set of circumstances brought aboutby the real estate market, zoning laws, client priorities,and architect’s tastes and fantasies. It is this singularityof tall buildings that has given impetus to the innovationsin the art of structural engineering.

In terms of absolute height, the tallest structure iscurrently the Burj Dubai, followed by dozens of radio

and television broadcasting towers which measure over600 metres (about 2,000 feet) in height. There is, however,some debate about:

• Whether structures under construction should beincluded in the list.

• Whether structures rising out of water should havetheir below-water height included.

For towers, there is debate over: whether guy-wire-supported structures should be counted?

For buildings, there is debate over:

• Whether communication towers with observationgalleries should be considered habitable buildings.

• Whether only habitable height is considered.• Whether roof-top antennas should be considered

towards height of buildings; with particular interestin whether components that look like spires can beeither classified as antennas or architectural detail.

The Council on Tall Buildings and Urban Habitat, theorganization that determines the title of the “World’sTallest Building,” recognizes a building only if at leastfifty percent of its height is made up of floor platescontaining habitable floor area. Structures that do notmeet this criterion, such as the CN Tower, are definedas “towers.”

The conservation and creation of energy in all buildings,not just in tall buildings, is accepted as a key tocounteracting the effects of climate change.

Structural schemes:• Braced tube scheme: Cross-bracing systems-

Exterior braced tube and Interior braced tube, bracedand framed tube combination- steel or composite

• Framed tube systems: single tube or twin tubes-steel or composite

• Nontubular schemes: Shear wall and frame, shearlinks, outrigger and belt truss, jumbo columnscheme- steel or composite.

Tallest structuresThe world’s tallest man-made structure is Burj Dubai, askyscraper under construction in Dubai that reached707 m (2,320 ft) in height on September 26, 2008. Whencompleted, it is expected to rise over 818 m (2,684 ft).

By 7 April 2008 it had been built higher than the KVLY-TV mast in North Dakota, USA, which is still the tallestcompleted structure at 628.8 m (2,063 ft). It officiallysurpassed Poland’s 646.38 m (2,121 ft) Warsaw radiomast, which stood from 1974 to 1991, to become thetallest structure ever built. Guyed lattice towers such asthese masts had held the world height record since 1954.

The CN Tower in Toronto, Ontario, Canada, standing at553.3 m (1,815 ft) is the world’s tallest completedfreestanding structure on land. Opened in 1976, it was


surpassed in height by the rising Burj Dubai onSeptember 12, 2007. It has the world’s second highestpublic observation deck at 446.5 m (1,465 ft).

The Petronius Platform stands 610 m (2,001 ft) off thesea floor leading some, including Guinness WorldRecords 2007, to claim it as the tallest freestandingstructure in the world. However, it is debated if below-water height should not be counted, in the same manneras underground “height” is not taken into account inbuildings. The Troll A platform is 472 m (1,549 ft), withoutany part of that height being supported by wires. Thetension-leg type of oil platform has even greater below-water heights with several examples more than1,000 metres (3,300 ft) deep. However, these platformsare not considered constant structures as the vastmajority of their height is made up of the length of thetendons attaching the floating platforms to the sea floor.

Taipei 101 in Taipei, Taiwan is currently the world’s tallestinhabited building in only one of the four main categoriesthat are commonly measured: at 509.2 m (1,671 ft) asmeasured to its architectural height (spire). Its roof height449.2 m (1,474 ft) and highest occupied floor 439.2 m(1,441 ft) have recently been overtaken by the ShanghaiWorld Financial Center (roof height 487 m (1,598 ft);highest occupied floor 474 m (1,555 ft)). The Sears Toweris highest in the final category: the greatest height totop of antenna of any building in the world at 527.3 m(1,730 ft).

CALL FOR NOMINATIONS FORICI (KBC) - UltraTech Endowment Award

for Outstanding Concrete Engineer of Karnataka - 2009ICI (KBC) - Birla Super Endowment Award

for Outstanding Concrete Structure of Karnataka 2009Indian Concrete Institute - Karnataka Bangalore Center, thought about the need to identify and honour an individualwho has worked for the cause of concrete and rendered significant contributions to the Research, Developmentand/or Application of Concrete and also about the need for recognising outstanding and innovative structures builtusing concrete. This idea has led to instituting of above two awards.

M/s. Grasim Industries Limited (Cement Division), Bangalore has instituted these awards. A committee ofexperts reviews the nominations received for the awards and selects the awardees for the year 2009. The decisionof the committee is final.

You/your organisation being one among those involved in the field of Concrete, ICI-KBC has decided to request youto nominate a person and a Concrete Structure, you think suitable for the awards.

The award giving ceremony is an important agenda in the ‘Concrete Day’ celebrations on 7th September everyyear. Every year nominations are invited for the awards. The information to be furnished in respect of thenominations can be obtained by email. We request you to kindly send your nominations on or before August10, 2009.

For details, please contact : Dr. M. N. HegdeSecretary, ICI - KBCMobile : 9741006095E-mail : [email protected]

On its completion, projected for 2009, Burj Dubai willbreak the height record in all four categories for completedbuildings by a wide margin. While the final height hasnot been released to the public, Greg Sang, theconstruction manager, says that the building will rise toa minimum of 700 m (2,297 ft). The developer, Emaar, iskeeping structural details secret due to competition forthe “world’s tallest” with other structures, including thenearby Al Burj. The Shanghai World Financial Centerhas the world’s highest roof, highest occupied floor, andthe world’s highest public observation deck at 474.2 m(1,556 ft). It will retain the latter record after thecompletion of Burj Dubai, as Burj Dubai’s observationdeck will be at 442 m (1,450 ft).

Tallest structure by categoryDue to the disagreements over how to measure heightand classify structures, engineers have created variousdefinitions for categories of buildings and other structures.One measure includes the absolute height of a building;another includes only spires and other permanentarchitectural features, but not antennas. The tradition ofincluding the spire on top of a building and not includingthe antenna dates back to the rivalry between theChrysler Building and 40 Wall Street. A modern-dayexample is that the antenna on top of the Sears tower isnot considered part of its architectural height, while thespires on top of the Petronas towers are counted.


Category Structure Country C i ty Height (m)

Skyscraper (under construction) -aall categories Burj Dubai United Arab Emirates Dubai 707

Guyed Mast KVLY-TV mast United States Blanchard, N.D. 628.8

Concrete Tower CN Tower Canada Toronto 553.3

Skyscraper - to top of antenna Sears Tower United States Chicago 527.3

Skyscraper - to top of spire Taipei 101 Taiwan Taipei 509.2

Skyscraper - to top of roof Shanghai World Financial Center People’s Republic of China Shanghai 492

Tower for scientific research BREN Tower United States Nevada Test Site 462

Mast radiator, insulated against ground VLF transmitter Lualualei United States Lualualei, Hawaii 458.11

Twin towers Petronas Twin Towers Malaysia Kuala Lumpur 452

Chimney GRES-2 Power Station Kazakhstan Ekibastusz 419.7

Radar Dimona Radar Facility Israel Dimona 400

Guyed tubular steel mast Belmont transmitting station United Kingdom Donington on Bain 387.7

Lattice tower Kiev TV Tower Ukraine Kiev 385

Partially guyed tower Gerbrandy Tower Netherlands IJsselstein 366.8

Electricity pylon Yangtze River Crossing, Jiangyin China Jiangyin 346.5

Bridge pillar Millau Viaduct France Millau 342

Iron tower Tokyo Tower Japan Tokyo 333

Five-sided building JPMorgan Chase Tower United States Houston 305

Dam Nurek Dam Tajikistan Nurek 300

Concrete dam Grande Dixence Dam Switzerland Val d’Hérens 285

Electricity pylon built of concrete Yangtze River Crossing, Nanjing China Nanjing 257

Clock tower NTT Docomo Yoyogi Building Japan Tokyo 240

Electricity pylon of HVDC-powerline Yangtze River Crossing, Wuhu China Wuhu 229

Minaret Hassan II Mosque Morocco Casablanca 210

Wind turbine Fuhrländer Wind Turbine Laasow Germany Laasow, Brandenburg 205

Cooling tower Niederaussem Power Station Germany Niederaussem 200

Monument Gateway Arch United States St. Louis, Missouri 192

90° twisted building Turning Torso Sweden Malmö 190

Masonry tower Anaconda Smelter Stack United States Anaconda, Montana 178.3

Inclined Structure, Stadium Le Stade Olympique Canada Montreal 175

Obelisk San Jacinto Monument United States Houston 173.7

Church building Chicago Temple Building United States Chicago 173

Masonry building Italy Torino 167

Masonry building Philadelphia City Hall United States Philadelphia 167

Ferris wheel Singapore Flyer Singapore Singapore 165

Church tower Ulm Minster Germany Ulm 162

Industrial hall Vehicle Assembly Building United States Kennedy Space Center 160

Memorial cross Santa Cruz del Valle de los Caídos Spain El Escorial 152.4

Table 1 shows the tallest structure by category


Roller coaster Kingda Ka United States Jackson, New Jersey 138.98

Tomb Great Pyramid of Giza Egypt Giza, Cairo 138.8

Dome St Peter’s Basilica dome Vatican City Vatican City, Rome 136.57

Air traffic control tower Suvarnabhumi Airport Thailand Bangkok 132.2

Flagpole, free-standing Ashgabat Flagpole Turkmenistan Ashgabat 133

Equilateral Pentagon Baltimore World Trade Center United States Baltimore 123.5

Statue (including pedestal) Ushiku Daibutsu BronzeBuddha Statue Japan Ushiku 120

Storage silo Henninger Turm Germany Frankfurt 120

Sculpture Spire of Dublin Ireland Dublin 120

Light advertisement Bayer Cross Leverkusen Germany Leverkusen 118

Wooden structure Gliwice Radio Tower Poland Gliwice 118

Aerial tramway support tower Pillar of third section ofGletscherbahn Kaprun Austria Kaprun 113.6

Electricity pylon of powerline for Bremen-Industriehafensingle phase AC Weser Powerline Crossing Germany Bremen 111

Lighthouse Yokohama Marine Tower Japan Yokohama 106

Sphere Stockholm Globe Arena Sweden Stockholm 85

Pre-modern Chinese pagoda Liaodi Pagoda China Ding County, Hebei 84

Lantern Tower Boston Stump United Kingdom Boston, Lincolnshire 83.05

Statue (not including pedestal) Mamayev Kurgan Russia Volgograd 82

Brick lighthouse Torre della Lanterna Italy Genoa 77

Brick minaret Qutub Minar India Delhi 72.5

Electricity pylon Pylon 310 of powerline(concrete, prefabricated) Innertkirchen-Littau-Mettlen Switzerland Littau 59.5

Monolithic obelisk Tuthmosis II Obelisk Italy San Giovanni in Laterano 36

Table 2. Tallest building by function

Category Structure Country C i ty Architectural top, m

Mixed Use* Burj Dubai** United Arab Emirates Dubai 707 (of est. 818)

Office Taipei 101 Taiwan Taipei 509

Mixed Use* (completed only) John Hancock Center United States Chicago 344

Hotel Rose Tower*** United Arab Emirates Dubai 333

Residential Q1 Australia Gold Coast, Queensland 322.5

Hotel (in use only) Burj Al Arab United Arab Emirates Dubai 321

Educational Moscow State University Russia Moscow 240

Hospital Guy’s Hospital United Kingdom London 143

Library W. E. B. DuBois Library United States Amherst, Massachusetts 116

* Mixed Use is defined as having both residential and office space.

** As Burj Dubai is still under construction and not yet inhabitable, it currently does not serve a specific function. Upon completion, it will serveas a mixed use building.

*** Although the Rose Tower is complete, it is not currently inhabited. Once the building’s hotel opens (target date of April 2008 was not met),the tower will become the world’s tallest building used exclusively as a hotel.


Up until 1998 the tallest building status was essentiallyuncontested. Counting buildings as structures with floorsthroughout, and with antenna masts excluded, the SearsTower in Chicago was considered the tallest. When thePetronas Twin Towers in Kuala Lumpur, Malaysia werebuilt, controversy arose because the spire extended ninemetres higher than the roof of the Sears Tower. Excludingthe spire, the Petronas Towers are not taller than theSears Tower.At their convention in Chicago, the Council on TallBuildings and Urban Habitat (CTBUH) reduced the SearsTower from world’s tallest and pronounced it not secondtallest, but third, and pronounced Petronas as world’stallest. This action caused a considerable amount ofcontroversy, so CTBUH defined four categories in whichthe world’s tallest building can be measured:1. Height to the architectural top (including spires and

pinnacles, but not antennas, masts or flagpoles).This measurement is the most widely utilized andis used to define the rankings of the 100 TallestBuildings in the World.

2. Highest Occupied Floor3. Height to Top of Roof4. Height to TipThe height is measured from the pavement level of themain entrance. At the time, the Sears Tower held firstplace in the second and third categories. Petronas heldthe first category, and the original World Trade Towersheld the fourth. Within months, however, a new antennamast was placed on the Sears Tower, giving it hold ofthe fourth category. On April 20, 2004, the Taipei 101 inTaipei, Taiwan, was completed. Its completion gave it

the world record for the first three categories. On July21, 2007 it was announced that Burj Dubai had surpassedTaipei 101 in height, reaching 512 m (1,680 feet) tall.However Burj Dubai is still under construction.Today, Taipei 101 leads in the first category with 509 m(1,671 feet), but has been surpassed in the second twocategories by the Shanghai World Financial Centerwhose roof height is 492 m (1,614 feet) and whose highestoccupied floor is at 474 m (1,555 feet). Before either ofthese buildings were completed, the first category washeld by the Petronas Twin Towers with 452 m (1,483feet), and before that by Sears Tower with 442 m (1,451feet). The second and third categories were held by theSears Tower, with 412 m (1,351 feet) and 442 m (1,451feet) respectively.The Sears Tower still leads in the fourth category with527 m (1,729 feet), previously held by the World TradeCenter until the extension of the Chicago tower’s westernbroadcast antenna in 2000, over a year prior to the TradeCenter’s destruction in 2001. Its antenna mast included,1 World Trade Center measured 526 m (1,727 feet). TheWorld Trade Center became the world’s tallest buildingsto be destroyed or demolished; indeed, its site enteredthe record books twice on September 11, 2001, in thatcategory, replacing the Singer Building, which once stooda block from the WTC site.Structures such as the CN Tower, the Ostankino Towerand the Oriental Pearl Tower are excluded from thesecategories because they are not “habitable buildings”,which are defined as frame structures made with floorsand walls throughout.

World’s tallest freestanding structure onlandFreestanding structures include observation towers,monuments and other structures not generally consideredto be “Habitable buildings”, but exclude supportedstructures such as guyed masts and ocean drillingplatforms.

The world’s tallest freestanding structure on land isdefined as the tallest self-supporting man-made structurethat stands above ground. This definition is different fromthat of world’s tallest building or world’s tallest structurebased on the percent of the structure that is occupiedand whether or not it is self-supporting or supported byexterior cables. Likewise, this definition does not count

structures that are built underground or on the seabed,such as the Petronius Platform in the Gulf of Mexico.

As of 12 May 2008, the tallest freestanding structure onland is the still under construction Burj Dubai in Dubai,United Arab Emirates. The building, which now standsat 636 m (2,090 ft), surpassed the height of the previousrecord holder, the 553.3 m (1,815 ft) CN Tower in Toronto,Ontario, on September 12, 2007. It is scheduled to becompleted in 2009, and is planned to rise to a height ofover 818 m (2,680 ft).

The following is a list of structures that have held thetitle as the tallest freestanding structure on land.

Table 3. History of record holders in each CTBUH category

Date (Event) Architectural top Highest occupied floor Rooftop Antenna

2008 Shanghai World Financial Taipei 101 Shanghai World Financial Shanghai WorldCenter completed Center Financial Center Sears Tower

2003: Taipei 101 completed Taipei 101 Taipei 101 Taipei 101 Sears Tower2000: Sears Tower antenna extension Petronas Towers Sears Tower Sears Tower Sears Tower1998 Petronas Towers completed Petronas Towers Sears Tower Sears Tower World Trade Center1996 CTBUH defines categories Sears Tower Sears Tower Sears Tower World Trade Center


Table 4 Tallest historical structuresRecord from Record to Name and Location Constructed Height (m) Notes

c. 2600 BC c. 2570 BC Red Pyramid of Sneferu, Egypt c. 2600 BC 105 c. 2570 BC c. AD 1311 Great Pyramid of Giza in Egypt c. 2570 BC 146 By AD 1439, the Great Pyramid

had eroded to a height ofapproximately 139 m (455 ft).

1311 1549 Lincoln Cathedral in England 1092–1311 160 The central spire was destroyedin a storm in 1549. While thereputed height of 525 ft isdoubted by A.F. Kendrick, othersources agree on this height.

1549 1625 St. Olaf’s Church in Tallinn, Estonia 1438–1519 159 The spire burnt down after alightning strike in 1625 and wasrebuilt several times. The currentheight is 123 m.

1625 1647 St. Mary’s Church in Stralsund, 1384–1478 151 The spire burnt down after aGermany lightning strike in 1647. The

current height is 104 m.1647 1874 Strasbourg Cathedral in France 1439 1421874 1876 St. Nikolai in Hamburg, Germany 1846–1874 1471876 1880 Cathédrale Notre Dame in Rouen,

France 1202–1876 151 1880 1884 Cologne Cathedral in Germany 1248–1880 1571884 1889 Washington Monument in

Washington D.C., United States 1884 169 1889 1930 Eiffel Tower in Paris, France 1889 300 First structure to exceed 300

metres in height. The addition ofa telecommunications tower inthe 1950s brought the overallheight to 324 m.

1930 1931 Chrysler Building New York, US 1928–1930 3191931 1967 Empire State Building, New York, US 1930–1931 381 First building with 100+ stories.

The addition of a pinnacle andantennas later increased itsoverall height to 1,472 ft/448.7 m.

1967 1975 Ostankino Tower in Moscow, Russia 1963–1967 537 Remains the tallest in Europe.Fire in 2000 led to extensiverenovation.

1975 2007 CN Tower in Toronto, Canada 1973–1976 553 Remains the tallest in the Americas2007 present Burj Dubai in Dubai, UAE 2004–2008 707.3 Current holder of world’s tallest

freestanding structure. Estimatedto rise higher than 2,625 ftwhen completed in 2009.

The CN Tower in Toronto, Ontario was the world’stallest freestanding structure on land from 1975

KVLY-TV mast, the height record holder from1963–1974 and 1991–2008

Burj Dubai in Dubai, United ArabEmirates is currently the world’s tallestman-made structure.

Figure 2 Tallest buildings and structures in the world


Figure 3. Diagram of the Principal High Buildings of the OldWorld, 1884

Notable mentions include the Pharos(lighthouse) of Alexandria, built in the thirdcentury BC, and estimated between 115 to 135m (383–440 ft). It was the world’s tallest non-pyramidal building for many centuries. Anothernotable mention includes the Jetavanaramayastupa in Anuradhapura, Sri Lanka, which wasbuilt in the third century, and was similarly tallat 122 m (400 ft). These were both the world’stallest or second tallest non-pyramidal buildingsfor over a thousand years.

The tallest secular building between the collapseof the Pharos and the erection of theWashington Monument may have been the Torredel Mangia in Siena, which is 102 m tall, andwas constructed in the first half of the fourteenthcentury, and the 97 m tall Torre degli Asinelli inBologna, also Italy, built between 1109 and 1119.

* This is the current height of Burj Dubai, as of26 September 2008. When completed, it isexpected to rise over 800 m (2,625 ft).

World’s highest observation deckTable 5. Timeline of development of world’s highest observation deck since inauguration of Eiffel Tower.

Held record Name and Location Constructed Height of highest Notes

From To observation deck (m)

1889 1931 Eiffel Tower, Paris, France 1889 275 Two further observation decks 57and 115 metres above ground.

1931 1973 Empire State Building, 1931 369 A second observation deck isNew York City, USA located on the 86th floor at

320 metres above ground.

1973 1976 World Trade Center, 1973 420 Destroyed during theNew York City, USA September 11, 2001 attacks

1976 2008 CN Tower, Toronto, Canada 1976 446.5 Two further observation decks342 and 346 metres above ground.

2008 present Shanghai World Financial 2008 474 Other observation decks are

Center, Shanghai, China 423 and 439 metres above ground.

Higher observation decks have existed on mountain peaks or cliffs, rather than on tall structures. For example, theRoyal Gorge Bridge in Cañon City, Colorado, USA, was constructed in 1929 spanning the Royal Gorge at a height of321 m (1095 ft.) above the Arkansas River.

Timeline of guyed structures on landAs most of the tallest structures are guyed masts and the absolute height record of architectural structures on landis since 1954 kept by them, here is a timeline of world’s tallest guyed masts, since the beginning of radio technology.

As many large guyed masts were destroyed at the end of World War II, the dates for the years between 1945 and1950 may be incorrect. If Wusung Radio Tower survived World War II, it was the tallest guyed structure shortly afterWorld War II.

ACCE (I) - Events at Glance

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Special Governing Council Meetingat Bangaloreheld on 20th June 2009

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7. World Financial Center, China8. Khalifa Sports City Tower, Qatar9. Burj Dubai, United Arab Emirates10. 30 St Mary Axe, United Kingdom11. Menara Telekom, Malaysia

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Table 6. Timeline of guyed structures on landHeld record Name and Location Constructed Height of highest Notes From To observation deck (m)

1913 1920 Central mast of Eilvese transmitter, 1913 250 Mast was divided in 145 m byEilvese, Germany an insulator, demolished in 1931

1920 1923 Central masts of Nauen TransmitterStation, Nauen, Germany 1920 260 2 masts, demolished in 1946

1923 1933 Masts of Ruiselede transmitter,Ruiselede, Belgium 1923 287 8 masts, destroyed in 1940

1933 1939 Lakihegy Tower, Lakihegy, Hungary 1933 314 Blaw-Knox Tower, insulated againstground, destroyed in 1945,afterwards rebuilt

1939 1945 Deutschlandsender Herzberg/Elster, 1939 335 Insulated against ground,Herzberg (Elster), Germany dismantled in 1945

1945 1946 Blaw-Knox Tower Liblice, Liblice, 1936 280.4 Demolished on October 17, 1972Czech Republic by explosives. Replaced in 1976

by 2 355 masts.

1946 1948 Lakihegy Tower, Lakihegy, Hungary 1946 314 Blaw-Knox Tower, Insulated againstground, rebuilt after destruction in 1945

1948 1949 WIVB-TV Tower, Colden,New York, USA 1948 321.9

1949 1950 Longwave transmitter Raszyn,Raszyn, Poland 1949 335 Insulated against ground

1950 1954 Forestport Tower, Forestport,New York, USA 1950 371.25 Insulated against ground

1954 1959 Griffin Television Tower Oklahoma,Oklahoma City, Oklahoma, USA 1954 480.5

1956 1959 KOBR-TV Tower, Caprock,New Mexico, USA 1956 490.7 Collapsed in 1960

1959 1960 WGME TV Tower, Raymond,Maine, USA 1959 495

1960 1962 KFVS TV Mast, Cape GirardeauCounty, Missouri, USA 1960 511.1

1962 1963 WTVM/WRBL-TV & WVRK-FMTower, Cusseta, Georgia, USA 1962 533 Located in Cusseta, Georgia

1963 1963 WIMZ-FM-Tower, Knoxville,Tennessee, USA 1963 534.01

1963 1974 KVLY-TV mast, Blanchard,North Dakota, USA 1963 628.8

1974 1991 Warsaw Radio Mast, Mast radiator insulated againstG¹bin, Poland 1974 646.4 ground, collapsed in 1991

1991 KVLY-TV mast, Blanchard,North Dakota, USA 1963 628.8

Tallest structures, freestanding structures, and buildingsThe list categories are:

• The structures (supported) list uses pinnacle height and includes architectural structures of any type that mightuse some external support constructions like cables and are fully built in air. Only the three tallest are listed, asmore than fifty US TV masts have stated heights of 600-610m (1969-2000 ft).


• The structures (media supported) list uses pinnacle height and includes architectural structures of any typethat are not totally built in the air but are using support from other, denser media like salt water. All structuresgreater than 500 m (1,640 ft) are listed.

• The freestanding structures list uses pinnacle height and includes structures over 400 m (1,312 ft) that do notuse guy-wires or other external supports. This means truly free standing on its own or, in similar sense, non-supported structures.

• The building list uses architectural height (excluding antennas) and includes only buildings, defined as consistingof habitable floors. Both of these follow CTBUH guidelines.

Table 7 - All supertall buildings (300 m and higher) are listed.Rank Name and location Year completed Architectural top Floors

Structures (supported)

1 KVLY-TV mast, Blanchard, North Dakota, United States 1963 629 m (2,064 ft) –

2 KXJB-TV mast, Galesburg, North Dakota, United States 1998 628 m (2,060 ft) –

3 KXTV/KOVR Tower, Walnut Grove, California, United States 2000 625 m (2,051 ft) –

Structures (media supported)

1 Petronius Platform, Gulf of Mexico 2000 610 m (2,001 ft) –

2 Baldpate Platform, Gulf of Mexico 1998 580 m (1,902.9 ft) –

3 Bullwinkle Platform, Gulf of Mexico 1989 529 m (1,736 ft) –

Freestanding structures

1 Burj Dubai, Dubai, United Arab Emirates (under construction) 2009 707.3 m 162(2,321 ft) (predicted)818 m (2,684 ft)(predicted)

2 CN Tower, Toronto, Ontario, Canada 1976 553 m (1,814 ft) –

3 Ostankino Tower, Moscow, Russia 1967 540 m (1,772 ft) –

4 Sears Tower, , United States 1974 527 m (1,729 ft) 108

5 Taipei 101, Taipei, Taiwan 2003 509 m (1,670 ft) 101

6 Shanghai World Financial Center, Shanghai, People’s Republic of China 2008 492 m (1,614 ft) 101

7 Oriental Pearl Tower, Shanghai, People’s Republic of China 1996 468 m (1,535 ft) –

8 John Hancock Center, Chicago, United States 1969 457 m (1,500 ft) 100

9 Petronas Tower I, Kuala Lumpur, Malaysia 1998 452 m (1,483 ft) 88

10 Petronas Tower II, Kuala Lumpur, Malaysia 1998 452 m (1,483 ft) 88

11 Greenland Square Zifeng Tower, Nanjing, People’s Republic of China 2009 450 m (1,476 ft) 89

12 Empire State Building, New York City, United States 1936 449 (1,472 ft) 102

13 Milad Tower, Tehran, Iran 2007 435 m (1,427 ft) –

14 Kuala Lumpur Tower, Kuala Lumpur, Malaysia 1995 421 m (1,381 ft) –

15 Jin Mao Building, Shanghai, People’s Republic of China 1998 421 m (1,381 ft) 88

16 Chimney of GRES-2 Power Station, Ekibastuz, Kazakhstan 1987 420 m (1,378 ft) –

17 Two International Finance Centre, Hong Kong 2003 415 m (1,362 ft) 88

18 Tianjin Radio and Television Tower, Tianjin, People’s Republic of China 1991 415 m (1,362 ft) –

19 Central TV Tower, Beijing, People’s Republic of China 1992 405 m (1,329 ft) –


Buildings

1 Taipei 101, Taipei, Taiwan 2003 509 m (1,670 ft) 101

2 Shanghai World Financial Center, Shanghai, People’s Republic of China 2008 492 m (1,614 ft) 101

3 Petronas Tower I, Kuala Lumpur, Malaysia 1998 452 m (1,483 ft) 88

4 Petronas Tower II, Kuala Lumpur, Malaysia 1998 452 m (1,483 ft) 88

5 Greenland Square Zifeng Tower, Nanjing, People’s Republic of China 2009 450 m (1,476 ft) 89

6 Sears Tower, Chicago, United States 1974 442 m (1,450 ft) 108

7 Jin Mao Building, Shanghai, People’s Republic of China 1998 421 m (1,381 ft) 88

8 Two International Finance Centre, Hong Kong 2003 415 m (1,362 ft) 88

9 CITIC Plaza, Guangzhou, People’s Republic of China 1997 391 m (1,283 ft) 80

10 Shun Hing Square, Shenzhen, People’s Republic of China 1996 384 m (1,260 ft) 69

11 Empire State Building, New York, United States 1931 381 m (1,250 ft) 102

12 Central Plaza, Hong Kong 1992 374 m (1,227 ft) 78

13 Bank of China Tower, Hong Kong 1990 367 m (1,204 ft) 70

14 Bank of America Tower, New York, United States 2008 366 m (1,201 ft) 54

15 Almas Tower, Dubai, United Arab Emirates 2008 360 m (1,181 ft) 74

16 Emirates Office Tower, Dubai, United Arab Emirates 2000 355 m (1,165 ft) 54

17 Tuntex Sky Tower, Kaohsiung, Taiwan 1997 348 m (1,142 ft) 85

18 Aon Center, Chicago, United States 1973 346 m (1,135 ft) 83

19 The Center, Hong Kong 1998 346 m (1,135 ft) 73

20 John Hancock Center, Chicago, United States 1969 344 m (1,129 ft) 100

21 Rose Tower, Dubai, United Arab Emirates 2007 333 m (1,093 ft) 72

22 Shimao International Plaza, Shanghai, People’s Republic of China 2006 333 m (1,093 ft) 60

23 Minsheng Bank Building, Wuhan, People’s Republic of China 2007 331 m (1,086 ft) 68

24 Ryugyong Hotel, Pyongyang, North Korea (topped out) 1992 330 m (1,083 ft) 105

25 China World Trade Center Tower 3, Beijing, People’s Republic of China 2008 330 m (1,083 ft) 74

26 Q1 Tower, Gold Coast City, Australia 2005 323 m (1,060 ft) 78

27 Burj Al Arab, Dubai, United Arab Emirates 1999 321 m (1,053 ft) 60

28 Chrysler Building, New York, United States 1930 319 m (1,047 ft) 77

29 Nina Tower I, Hong Kong 2007 319 m (1,047 ft) 80

30 New York Times Building, New York, United States 2007 319 m (1,047 ft) 52

31 Bank of America Plaza, Atlanta, United States 1992 312 m (1,024 ft) 55

32 U.S. Bank Tower, Los Angeles, United States 1989 310 m (1,017 ft) 73

33 Menara Telekom, Kuala Lumpur, Malaysia 2001 310 m (1,017 ft) 55

34 Jumeirah Emirates Towers Hotel, Dubai, United Arab Emirates 2000 309 m (1,014 ft) 56

35 One Island East, Hong Kong 2008 308 m (1,010 ft) 70

36 AT&T Corporate Center, Chicago, United States 1989 307 m (1,007 ft) 60

37 The Address Downtown Burj Dubai, Dubai, United Arab Emirates 2008 306 m (1,004 ft) 63

38 JPMorgan Chase Tower, Houston, United States 1982 305 m (1,001 ft) 75

39 Baiyoke Tower II, Bangkok, Thailand 1997 304 m (997 ft) 85

40 Two Prudential Plaza, Chicago, United States 1990 303 m (994 ft) 64


Under constructionNumerous supertall skyscrapers are in various stagesof proposal, planning, or construction. Each of thefollowing are under construction and, depending on theorder of completion, could become the world’s tallestbuilding or structure in at least one category:

• Burj Dubai , under construction in Dubai, UAE, isexpected to be 818 m (2,684 ft) tall. It is currentlyunder construction, and as of 26 September 2008,it is 707 m (2,319.6 ft) tall, with 160 completed floors.It is currently taller than the CN Tower, the tallestcompleted freestanding structure. If completed, itwill be the tallest manmade structure of any kind inhistory. Construction began in September 2004 andcompletion is expected in September 2009.

• The Pentominium, under construction in Dubai, isexpected to be 618 m (2,028 ft) tall and have 120floors. If completed, it will be the tallest all-residentialbuilding in the world. Construction began in 2007and completion is expected in 2011.

• The Russia Tower, under construction in Moscow’sInternational Business Centre, is expected to be612.2 m (2,009 ft.) tall and have 118 floors. Ifcompleted, it will surpass the belowmentionedFederation Tower East as the tallest building inEurope. Construction began in September 2007 andcompletion is expected in 2012.

• Incheon Tower is a 151-floor, 610 metres (2,000 ft)tower in Incheon, South Korea. It is estimated to becompleted in 2012.

• The Guangzhou TV & Sightseeing Tower, underconstruction in Guangzhou, China, is expected tobe 610.0 m (2,001 ft) tall. If completed, it will betallest concrete tower, as well as the tallest structurein Asia. Construction began in November 2005 andcompletion is expected in 2009.

• The Chicago Spire (formerly Fordham Spire), underconstruction in Chicago, is expected to be 609.6 m(2,000 ft) and have 150 floors. If completed, it wouldsurpass the CN Tower as the tallest freestandingbuilding in North America[16], and would be the secondtallest all-residential building in the world (behindthe aforementionned Pentominium). Constructionbegan in June 2007 and completion is expected inearly 2012.[17]

• The Jakarta Tower (Menara Jakarta) is currently on-hold in Jakarta, Indonesia. It is expected to be 558m (1,831 ft.) tall up to the antenna, thus may betallest concrete tower. It is expected to be completedin 2011.

• The Federation Tower East, under construction inMoscow’s International Business Centre, isexpected to be 506 m (1,660 ft.) tall (to the tip of thespire) and have 93 floors. If completed, it will surpassthe aforementionned Mercury City Tower as the

tallest building in Europe. Construction began in2003 and completion is expected in 2009.

References1. Bryan Stafford Smith Alex Coull. (1991). Tall Buildings:

Analysis and Design, John Wiley & Sons. Inc, New York.2. Bungale S. Taranath. (1988). Structural Analysis and

Design of Tall Buildings, McGraw Hill Book Company.New York.

3. Bungale S. Taranath. (1998). Steel, Concrete, andComposite Design of Tall Buildings, McGraw Hill BookCompany. New York.

4. “CTBUH Criteria for Defining and Measuring TallBuildings”. Council on Tall Buildings and Urban Habitat.Retrieved on 2008-08-19.

5. “Burj Dubai now a record 707m tall and continues torise”. Emaar. Retrieved on 2008-09-26.

6. Emaar. “Burj Dubai surpasses KVLY-TV mast tobecome the world’s tallest man-made structure”. Pressrelease. Retrieved on 28 May 2008.

7. “CN Tower dethroned by Dubai building”, CBC News(2007-09-12). 2 September 2008.

8. Emaar Properties PJSC (2007-09-13). “Burj Dubaiscales 150 storeys and is the world’s tallest free-standing structure”. Press release. Retrieved on 2September 2008.

9. “Dubai building surpasses CN Tower in height”,CTV.ca, CTVglobemedia (2007-09-13).

10. “On Top of the World”, Time (2007-07-18). Retrievedon 24 February 2008.

11. BBC News, Dubai skyscraper world’s tallest12. “Highest Dams (World and U.S.)” (chart). 1998 ICOLD

World Register of Dams. Retrieved. 2007-08-11.13. Guinness World Records - Science & Technology-

Structures 2008.- World’s Highest Concrete Dam.14. “Flag of Turkmenistan”. Official Homepage of the

Republic of Turkmenistan (July 03, 2008).15. CTBUH Criteria for Defining and Measuring Tall

Buildings16. The Project Gutenberg eBook of The Cathedral Church

Of LINCOLN, by A.F. KENDRICK, B.A17. “The Empire State Building”. Wired New York. Retrieved

on 2007-12-23.18. Height for inhabited buildings with floors; does not

include TV towers and antennas.19. Chicago Business News, Analysis & Articles | Calatrava

tower to drop spire | Crain’s20. Shelbourne Development. (2008, April 06). The

Chicago Spire Achieves 30 Percent Sales. RetrievedJune 14, 2008 from http://w w w . s h e l b o u r n e d e v e l o p m e n t . c o m /press_release.php?id=96

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ABSTRACTCivil infrastructure plays a very important role in thedevelopment of any country. However, due to severalreasons, such as adverse environmental conditions,increased vehicular load etc., structures often fail toperform satisfactorily even before the stipulated designlife. Therefore, to prevent sudden failures before theservice life, a new concept called health monitoring isgaining importance. Health monitoring is performed bymeans of sensors, such as accelerometers, straingauges and piezo-sensors, through which changes instructural static/ dynamic behaviour caused by damageare detected. This paper has two parts; the first partcovers damage location and severity assessment usingthe changes in natural frequencies taking aid of the modeshapes of the undamaged structure using finite elementmethod. The second part deals with how financial savingscan be achieved by structural inspection/ maintenanceby using proper health monitoring approach. A case studyis taken up for practical demonstration. This studyconcludes that by adopting a monitoring technique, theinitial cost might be marginally higher, but in the longterm, it reduces the overall cost drastically (through lessmaintenance cost and repair cost).

Key words: Structural Health Monitoring (SHM), Damagedetection

INTRODUCTIONSustained economic growth and social development ofany country is intimately linked to the reliability anddurability of its civil infrastructures such as highwaysand related structures. Bridges are the most critical yetvulnerable elements in highway transportation networks.These structures are constantly exposed to aggressiveenvironment and face ever-increasing traffic volumes andheavier truck loads. This may exert serious, wide spreadand prolonged adverse impacts on various societalsectors. Failure of a bridge can cause enormous adverseimpacts locally to the bridge site and also globally tothe network. Bridge failures disrupt normal traffic flows,lead to reduced network accessibility and increased usercosts in terms of travel delay, detour and extra vehiclefuel consumption as well as higher probability ofaccidents.

In order to ensure satisfactory long-term safety andperformance of highway networks, proactive/reactivemaintenance, rehabilitation and/or replacement must becarried out in a timely and adequate manner for mitigatingprogressive deterioration and for correcting majorstructural defects. In a significant number of cases, the

Infrastructure Health Monitoring For ManagementRamesh Babu.K.H; Bhalla, Dr. Suresh; Neeraj, Vyom

Department of Civil Engineering, Indian Institute of Technology DelhiHauz Khas, New Delhi 110 016 (INDIA)

time span between successive inspections is longenough for minor structural damage to initiate, evolve intomajor damage, and eventually cause collapse of thestructure (1). Health Monitoring of structure is gaininggreat importance in the field of civil engineering over theperiodic (regular) maintenance, due to the fact thatmonitoring system can detect damages as they occurin the structure. By implementing a health monitoringtechnique on a structure there are several benefits suchas service life of the structure can be enhanced, cost formaintaining the structure can be reduced. The objectiveof this paper can be divided into two main parts: Firstly,to detect damage location and also severity of damageby the naidu and soh method. Secondly, cost benefitanalysis of a structure with the use of health monitoringsystem and with out any monitoring system (i.e.periodical maintenance) for different cases (i.e. bychanging the severity of damage and the damagelocation).

HEALTH MONITORING OF STRUCTUREStructural Health Monitoring (SHM) is defined as themeasurement of the operating and loading environmentand the critical responses of a structure to track andevaluate the symptoms of operational incidents,anomalies and/or deterioration or damage indicators thatmay affect operation, serviceability or safety reliability(2).

The main principle of health monitoring is based on findingthe change in the natural frequencies from the undamagedstate. This change in natural frequencies depends uponthe severity of the damage and location of the damage.For example, as the severity of damage increases, thechange of natural frequencies between will also beincreasing. In the same way, the location of the damagealso affects the change in natural frequencies, like thedamage at the central part of the bridge will have moreadverse affect than the damage at the supports.

WHY AND WHERE TO IMPLEMENT HEALTHMONITORINGThe most important questions answered by this paperwould be, by using a health monitoring technique, how itis beneficial to the structure (may be to that the user)and other one will be where this health monitoring shouldbe taken up.

As far the former question is concerned the answer isthat SHM is definitely beneficial. In a significant numberof cases, the time span between successive inspectionsis long enough for minor structural damage to initiate,evolve into major damage, and eventually cause collapse


of the structure (3). On the other hand in case of structurewhich uses monitoring technique, the damages aredetected as they and when are formed. But this involvesextra cost at the initial stage of construction. However,this cost will be negligible when compared to the cost itwill be saving in the future/later date (long run). How muchwe can save in long run has been studied using a real lifecase study. The case study is of a steel bridge of 20.3mspan.

The some of the advantages we derive from monitoring ofthe structure are:

• SHM facilitates management decisions dependingon the severity of damage and the locations ofdamage (retrofit or demolish the structure).

• Minimization of the maintenance cost and also thecost to be incurred for retrofitting or repairing if thestructure is damaged.

• Predict the life of the structure.

The health monitoring technique can be used almost allstructures such as bridges, buildings, tunnels, powerplants and nuclear reactors. The accessories needed formonitoring the structure are accelerometer, multimeter,strain gauges, piezoelectric patches (PZT patches) andcomputer.

DAMAGE DETECTION IN STEEL BEAMIntroductionGlobal damage or fault detection, as determined bychanges in the dynamic properties (i.e. modalparameters, notably resonant frequencies, mode shapesand modal damping) or response of structures. Changesin physical properties of the structure, such as itsstiffness or flexibility due to damage will cause changesin the modal properties. Based on the amount ofinformation provided regarding the damage state, thesemethods can be classified into four categories (4):

1) Identify that damage has occurred;2) Identify that damage has occurred and determine

location of damage;3) Identify that damage has occurred, locate damage

and estimate its severity and4) Identify that damage has occurred, locate damage,

estimate its severity and determine the remaininguseful life of the structure.

Current damage detection methods are either visual orlocalized experimental methods such as acoustic orultrasonic methods, magnetic field methods, radiography,eddy-current methods and thermal field methods. In thispaper, a method has been discussed which providesinformation about level 4. The method is low frequencyvibration technique based on piezoelectric ceramic (PZT)patches.

Naidu and Soh (5) described the electromechanical (E/M) impedance method integrated with a finite element

(FE) model as a means for damage location identificationusing higher modes. Damage location is identified bycorrelating the changes in natural frequencies (for highermodes) with the corresponding mode shapes of theundamaged structure. The natural frequency shifts of thestructure are obtained from the shifts in the peaks if theE/M admittance signatures of smart piezo-transducersbonded on to the host structure. The mode shapes areobtained from the equivalent FE model of the undamagedstructure. The advantages of this method are:

1) A single or a pair of piezo-transducer is sufficient tolocate the damages in small structures (withhomogeneous materials). This method can beexploited for economical health monitoring ofstructures such as trusses.

2) The knowledge of mode shape changes for thedamaged structure is not required.

3) Piezo-transducers being light-weight and non-intrusive to the structure do not significantly affectthe natural frequencies of the system.

4) The sensitivity of the technique to incipient damagesis high.

The governing equation for calculating the DI values foreach element of the beam is as follows (5):

As we can see from this equation, 2 sets of data arerequired.

1. The shifts in fundamental frequency for each stageof damage (comparing predamage and post-damagemodal analysis)

2. The values for the curvatures.

The advantage of this method is that it eliminates theneed to obtain the mode shapes by experimental modalanalysis, which requires lots of transducers and is alsonot very accurate. The damage indicator for an elementis nothing but the weighted average of the elementdeformation parameters, ÄE, over the chosen m modes,which have the largest frequency changes. The damagelocation is then identified as the element that has themaximum DI value.

The above mentioned method can be demonstratedexperimentally on a 2m long structural stainless steelbeam and the sectional details are shown in Fig.1.

The boundary condition of the beams used forcomputational and theoretical analysis is simply


supported pin-pin end supports. To simulate this, 2 angles(ISA) were welded onto the beam at its two ends. Thelength of the beam between supports was 1.9m. A cut ofwidth 3 mm was created in the top flange of the beam atdistance of 625 mm from the left support using amechanical saw as shown in Fig. 2. The cut was madein two stages. In the first stage, the cut was made up to7.6 mm depth. It was extended to a depth of 80mm inthe second stage.

Modal analysis is done for this beam both theoreticallyand FEM analysis (using ANSYS 9.0). A 1-D analysiswas also done using ANSYS 9.0 to obtain the values ofthe element displacements from mode shapes and tohence calculate the Damage Index for each element.This was not done to get the frequencies, but to ratherobtain the displacements for each element of the FEmesh. Young’s modulus was considered as 2 x 1011pa,density as 7700 kg/m3 and Poisson’s ratio as 0.3.

Since the 2m beam can only have 2 modes less than1000Hz, hence only the 1st 2 modes were taken intoaccount. It is clear from the displacement values that athigher modes, the displacements increase. Also, thesedisplacements are in concordance with the general viewof the 1st and 2nd modes.

Fig. 3 shows the DI values of the elements correspondingto the two stages of damages. From this figure, the 6thelement, whose mid point is located 522.5 mm from theleft end, is identified as the damaged element, which isvery close to the actual damage location. It is also foundthat as severity of damage increases, DI values increasecorrespondingly.

BENEFIT COST ANALYSIS: CASE STUDYIntroductionAfter finding the damage location and severity of damage,now it is very important to take necessary preventivemeasures (i.e. maintenance). If damages are not takencare in the early ages, these can become more severeat the later stage. These damages may be due toenvironmental affects, increased traffic loading and dueto the end of service life of the elements of the structure.In general, structures in better condition need smallermaintenance costs than structures in poor condition toreach the same reliability level by using the same typeof maintenance intervention. By implementing healthmonitoring technique for a structure, not only the servicelife of the structure will improve but also resources canbe saved drastically when compare to the structure withregular maintenance. Real life case study is presentedin this section to quantitatively estimate the benefits.

MethodologyIn general construction, inspection, maintenance andfailure costs are essential for the life cycle costing (LCC)analysis of deteriorating structures. This analysis

includes direct and indirect costs. The direct cost, oftencalled the agency cost in bridge management systems,consists of costs of material, labour and scaffold, amongothers. The major component of indirect costs is theuser cost obtained by quantifying service losses suchas traffic delay.

In this analysis, we have taken only direct cost intoconsideration and see how cost can be reduced withmonitoring technique. The maintenance can also bedivided into two types - general inspection (i.e. visualinspection) and detailed inspections. General inspectiondone without any priority to damage is done visually bychecking the structure. This is done at an interval ofaround 2-3 yrs or till the first detailed inspection,depending on the importance of the structure and thebudget to be invested on that structure. Detailedinspection or maintenance is done when some damagein the structure is identified and this is done to checkthat it does not turn to severe damage. Generally, thistype of maintenance is done for an interval of 8 to 10yrs.In this study the interval for detailed maintenance is takenas 8yrs.

As infrastructure plays very important role in the progressof the country, it is very important the necessarymaintenance interventions should be taken into accountsuch that the structure remains functional. So, thereshould be a monitoring technique for structure to takecare of this. The instruments used for monitoring astructure give the signals (data or frequencies) whichcan be used as input for the methods used for detectingthe location and the severity of damage. The continuousmonitoring of the structure is done and if there is anyproblem in the system (or structure) it is detectedimmediately and necessary measures is taken to makesure, that the damage is not extended any more. So inthis way, we will be saving lots of lots of money to bespent unnecessarily on the maintenance of the structure.

This monitoring technique is like the famous proverb“prevention is better than curing the disease”. To showhow the cost can be saved with the implementation ofmonitoring technique, we will go through a steel bridge(Railway Bridge).

Case Study: Steel BridgeThis bridge is serving the Northern Railways, the BridgeNumber is 170 under Gaziabad section and it is situatedat 126.630 km Dasna. In Fig.4 shows the section of thesteel bridge and the elements dimensions are given below

Overall Span of the Bridge = 19.65m

Clear Span b/w bearings = 19.4 m

Depth of the Channel Section (girder) = 1788 mm

Distance between two girders = 1830mm


1st Top Flange Plate = 360 x 25 x 9825 mm

2nd Top Flange Plate = 360 x 12 x 8983 mm

Main Angle Section = 150 x 150 x 16 x 9825 mm

Vertical Stiffeners = 125 x 75 x 8 mm

Gusset Plate = 330 x 10 x 345 mm

All holes are 21.5 mm diameter for 20 mm dia. ShopRivets and All holes are 23.5 mm dia. for 22 mm dia.Field Rivets. Total steel per span (inclusive of wastage)= 29 tonnes

In this analysis, the main concern is to use the directcost (initial cost) involved in the construction of thestructure and see how much saving can be achieved byvarying the damage locations and also varying theseverity of damages, as the life of structure increases.The maintenance for the structure also varies dependingon the location of the damage and the severity. In thissteel bridge, the analysis is carried out in three differentcases and each case is explained in detail below. Asthe bridge is symmetrical, half of the span is taken foranalysis and which will hold good for the other half span.

Case 1: the damage at 3.5m from support

Case 2: the damage at 6.5m from support

Case 3: the damage at the centre (at joint between boththe spans) which will be most severe damage for thisbridge.

The above three cases are use to show how cost can bereduced by using health monitoring technique over normalperiodic maintenance depending upon the severity andlocation of damage. The initial cost for the constructionof the superstructure is approximately Rs. 32,50,000. Inthis cost of steel, cost of labour, cost of machinery, costof riveting, cost of painting and miscellaneous cost allare included. The additional cost to be incurred due toimplementation of health monitoring for the structure isequal to Rs. 2,30,000. The additional cost due to use ofhealth monitoring technique comes to be 7% of the initialcost. Already, we have seen that there are two types ofmaintenance, first General inspection (NormalMaintenance) and the second one is detailed inspection.The net present value (NPV) to be incurred in the first 10yrs for normal maintenance is equal to Rs. 1,77,000.

Detailed MaintenanceThis type of maintenance is carried out whenever it isrequired i.e. when the damage in the structure shouldbe restricted and when the damage is more severe. Buthere it is assumed that the detailed maintenance is donefor every 8yrs as the damages occurs during this period(8yrs) due to the increased traffic load and otherenvironmental factors. The detailed inspection is carriedout in the 14th yr, 22nd yr, 30th yr, 38th yr, 46th yr, 54thyr and 64th yr which are considered for analysis.

There will be comparison between costs for detailedinspection and for health monitoring technique. Theaccessories used for monitoring the structure are verysensitive and if any damages occur in the system theycan be easily detected and necessary measures canbe taken to control the damages detected in the structure.So by this, the cost to be invested for repairing thedamages detected at the early stage of the damage willbe less when compared to the period maintenance(which is done over a regular interval of time, during whicha small damage can become more severe demolitionnecessitating of the structure could be done).

Let us assume that damage has occurred in the structurein the 12th yr. Due to the monitoring technique, thedamage is detected in the 12th yr itself where as in caseof periodic maintenance (normal maintenance) this willbe detected and repaired in the 14th yr. In these twoyears the small damage would have been more severe.

Case 1: the Damage at 3.5m from end supportTable 1 shows the year in which detailed maintenanceand monitoring are conducted, actual cost and NPV inthose years for damage at 3.5m. Fig. 5 shows the plotbetween cost in Rupees and number of years for detailedmaintenance and with monitoring for damage at 3.5mfrom the end support. Fig. 6 shows the plot betweenNPV (in Rupees) and number of years for detailedmaintenance and with monitoring for damage at 3.5mfrom the end support.

From these plots, Net Saving for Damage at 3.5m

= Total cost due to Maintenance – Total cost forMonitoring

= Total cost for Normal Maintenance + Total cost forDetailed

Maintenance – Total cost for Monitoring – Initial Cost forMonitoring

= 300000 + 15290000 – 9145000 – 230000= Rs. 62,15,000

Case 2: Damage at 6.5m from end support

Table 2 shows the year in which detailed maintenanceand monitoring is taken up, actual cost and NPV inthose years for damage at 6.5m. In Fig.7 show the plotbetween cost in rupees and number of years for detailedmaintenance and with monitoring for damage at 6.5mfrom the end support and the Fig.8 show the plot betweenNPV in rupees and number of years for detailedmaintenance and with monitoring for damage at 6.5mfrom the end support.

From these plots, Net Saving for Damage at 6.5m

= Total cost due to Maintenance – Total cost forMonitoring


= Total cost for Normal Maintenance + Total cost forDetailed

Maintenance – Total cost for Monitoring – Initial Cost forMonitoring

= 300000 + 14885000 – 9190000 – 230000

= Rs. 57,65,000

Case 3: Damage at centre of the span

In Table 3 show the year in which detailed maintenanceand monitoring is taken up, actual cost and NPV in thoseyears for damage at 6.5m. In Fig.9 show the plot betweenCost in Rupees and Number of years for DetailedMaintenance and with monitoring for damage at 9.5mfrom the end support and the Fig.10 show the plotbetween Net Present Value (NPV) in Rupees and Numberof Years for Detailed Maintenance and with monitoringfor damage at 9.5m from the end support (Centre of theSpan).

From these plots,Net Saving for Damage at Centre (or Joint) of Span =Total cost due to Maintenance – Total cost for Monitoring= Total cost for Normal Maintenance + Total cost forDetailed Maintenance – Total cost for Monitoring – InitialCost for Monitoring = 300000 + 17365000 – 9195000 –230000 = Rs. 79,70,000

Summary ResultsTable 4 shows the net savings for the damage at differentlocations of the span. As the damage approaches thecentre of the span, more savings occurs and also as theseverity of damages increases, the net savings will bemore. The Fig.11 shows the data in the graph form.

CONCLUSIONSThis paper has performed a benefit cost analysis forstructural health monitoring.

Following conclusions can be derived:

1) For detecting the damage location and the severityof the damage, Naidu and Sohs (2004) method canbe effectively used. This method gives more accurateresults when compared to any other method.

2) By utilizing health monitoring technique for astructure, initially it may cost more (5% to 15 % ofthe initial cost). But the cost it saves in the lateryears is significant which is very well proven fromthe results of the case study.

3) Directly we may not be able to predict the servicelife of the structure but if we go through the analysispart of steel bridge, we can see that due to damageat the centre of the span the service life of bridge isrestricted.

4) Due to use of this health monitoring technique onthe infrastructures (bridges), not only there isconsiderable saving in the cost of maintenance but

also more importantly the time and the user cost(user convenience) can be saved greatly due to littleor less repairs works. The net savings which areshowed are on conservative side (because thedamage can be detected at much early stage than

what is taken for analysis by using monitoring system).

AUTHOR AFFILIATION (S)Ramesh Babu K H, Former postgraduate student(Corresponding author), Email:[email protected]

Dr. Suresh Bhalla, Assistant Professor, Email:[email protected] Vyom Neeraj, Formerundergraduate.

REFERENCES1) Liu.M, Frangopol.D.M (2006). “Optimizing Bridge Network

Maintenance Management under Uncertainty with ConflictingCriteria: Life-Cycle Maintenance, Failure, and User Costs.”Journal of Structural Engineering, Vol.132, No.11 (November),pp.1835-1845.

2) Aktan.A.E, Catbas.F.N, Grimmelsman.K.A and Tsikos.C.J(2000). “Issues in Infrastructure Health Monitoring forManagement”. Journal of Engineering Mechanics, Vol.126,No. 7 (July), pp.711-724.

3) Elkordy MF, Chang KC, Lee GC (1994). “A Structural DamageNeural Network Monitoring System”. Microcomputers in CivilEngineering, Vol.9, No.2, pp.83-96.

4) Rytter.A (1993) “Vibration based inspection of Civil EngineeringStructures”, Doctoral Dissertation, Department of BuildingTechnology and Structural Engineering, University of Aalborg.

5) Naidu A.S.K and Soh C.K (2004). “Identify Damage Locationwith Admittance Signatures of Smart Piezo-transducres”,Journal of Intelligent Material System and Structures, Vol.15,pp 627-642





Role of AdmixturesRole Admixtures.Shivram B Bagade, Conrete Technologist

History of Chemical Admixtures:The first superplasticizers were introduced in 1930s. Theywere syenthetically prepared water soluble organicpolymers.An important class of these polymers is Poly-Napthalyene Sulphonates (PNS),which since 1938 havebeen known as “Cement dispersing agents”.Thesesuperplasticizers were effective in improving theworkability of concrerte.However,very little interest wasshown to these compounds, since concrete designstrengths were low and water content could be easilyadjusted to achieve the desired workability.

What are Chemical Admixtures?By defination,admixtures are substances, organic orinorganic, in soild or liquid state, which when added toconcrete, at the time of mixing or before placing ofconcrete,interact with thehydrating cementitious systemby physical, chemical or physico-chemical action andthereby modifing the one or more properties of concretein its fresh, hardening or hardened state.

According to IS:9103-1999, admixture are defined as:

“A material other than water, aggregates and cement andadditives like pozzolana or slag and fiber reinforcement,used as an ingredient of concrete or mortar and addedto the batch immediately before or during its mixing tomodifing oneor more properties of concrete in the plasticor hardened state”.

However, until early 1930, the composition of concreteconsisted primarly of cement, aggregates and water. Theaccidental discovery of the benefits of air entrainment inconcrete by chemical admixtures in the 1940’s was thefirst major breakthrough in concrete technology. Thisfinding rapidly led to the development of several chemicalproducts and admixtures that enhanced various propertiesof concrete such as workability, setting time and earlystrength. Although admixtures generally used to be by-products of particular primary material production, thateventually found an application as concrete admixtures,they are now being manufactured as main products asthe construction industry stared looking for admixturesin large quantities.

Chemical admixtuers have become one of the essentialcomponents of concrete in concrete technology in recentyears. Various chemical admixtures, in most casesorganic compounds, differing in composistion, have beenoffere to the users today, in response to the needs of theconstruction market. The most commonly used of theseadmixtuers are the plasticizer and superplasticizerswhich have the abiliy of increasing the workability ofconcrete considerably.

Why Admixtures are needed?The construction industry has always been faced withthe problem of concrete, arsing from the basic conflictbetweeen the design engineer and the site engineer. Thedesign engineer invariably concentrates mainly on themeans of achieving high strenght at low cement contentand low water to cement ratio. On the other hand, theconstruction engineer places greater emphasis on quickand easy methods of placing the concrete. His idealconcrete therefore, is the one having high workabilityand hence the temptation to add a little more water whichis detrimental to the strength and durability of concrete.The long felt necessity of having a concrete with highworkability without compromising on strength anddurability criteria or reducing the water requirement ofthe mix and thereby obtaining higher strenght, can beachieved by using chemical admixtures, specificallysuperplasticizers.

From concrete technology point of veiw,a water to cementratio of 0.2475 approximately 0.25 is sufficient forhydration of cement in concrete.However,in practice suchconcrete is failed with workability point of view.water tocement ratio of 0.6 to 0.7 is required when no admixturesare used.Depending on sand and filler content theworkability of these mixes is not necessarily good. Lossof strength, durability,segregation and bleeding are theproblems faced in relation to high water content.Goodconcrete without the use of Admixtures is difficult to placeand requires intensive and time consuming vibration forfull compaction,which may in turn disturb the process ofhydration.In order to improve workability or reduce thewater requirement,water reducing admixtures are must.

An essential benefit of adding admixtures,on theproperties of fresh or hardened concrete is notably itsdurability enhancing ability.This is one of the reasonsthat admixtures have become a mandatory ingredient inmodern concrete. It is no more an avoidable luxury.Goodconcrete is possible only with the admixtures and properconcrete mix designs.


What is the purpose of admixture?They are used for various purposes,such as:1. Pumpability/Flowablity of fresh concrete.2. High strength through reduced water to cement ratio.3. Durable and non permiable concrete.4. Self compaction.5. Freze-Thaw resistance.6. Corrosion Inhibition.7. Expansion or shrinkage compensation.8. To make High early strength concrete/High

performance concrete.9. Retardation and Acceralation of time of setting.

Concreting of deep piles and poorly accessiblefoundations using SCC has been enabled. Admixtureshave facilitated many new technologies inTransportation,placement and compaction of concretebecause of which it is now possible to place very largepours without construction joints,transportation ofconcrete for longer distances,placing under congestedreinforcement is possible today.

Based on there usages the Admixtures are classified asfollows:

1. Air entraining agents.2. Accelerators.3. Water reducers.4. Gas-Forming agents.5. Alkali-aggregate expansion inihibitors.6. Water reducing and workability agents.7. High range water reducers.(Superplasticizers).8. Grouting agents.9. Bonding agents.10. Colouring agents.11. Anti-Freeze additives.12. Fungicidal admixtures.13. Corrosion Inhibiting admixtures.14. Shrinkage reducing or shrinkage compensation

admixtures.15. Damp proofing and surface hardeners,Etc.

Superplasticizers:They are also known as high-range water reducers,are agroup of admixtures,which possess,as their primaryfunction,the ability to produce concrete of givenworkability,at a lower water to cement ratio than that ofcontrol concrete containing no superplasticizers.

• Superplasticizers are usually water-soluble longchained organic polymers.

• Superplasticizers based on different types ofchemicals are available.some are syenthetic andothers are derived from natural products.

• ASTM C494-92 refers to superplasticizers as waterreducing,high range admixtures.

• According to IS 9103-1999,

“Superplasticizer is an admixture for mortar orconcrete,which imparts very high workability or allows alarge decrease in water content for a given workability.

Role of superplasticizers (Admixtures):The three different roles of admixtures are as follows:

1. To increase workability of the mix without changingthe mix composition in order to enhance placingcharecterstics of concrete.

2. To reduce the mixing water (or water demand) andthe water to cement ratio in order to increasestrength and improve durability,for a given workability.

3. To reduce both water and cement at a givenworkability in order to save cement and hence toreduce the problems associated with heat of cementhydration.

The changes in the Proprties of Concrete because ofAdixture and the savings for the user:• Primary properties affected

– Workability– Water cement ratio (hence other properties)– Stiffening / setting– Air content– Cohesion– Strength / strength development

Classification/Types of Admixtures as per ASTM C494 and BASF Products:


Admixture Benefits:• Direct savings - Materials cost• Indirect savings - Construction time or method• Long term savings - Improved concrete quality and

durability.

Direct Savings:• Lower cement content• Improved performance of cement replacements• Cheaper aggregate source

Indirect savings:• Increased workability without loss of strength• Savings in plant and labour• High early strength• Quicker access to or use of the structure• Energy savings - precast with thermal curing• Special properties - new or improved method of

construction• Quicker turn around on moulds or shuttering• Workability retention• Delayed stiffening• Improved durability• Lower permeability• Increased freeze thaw / salt scaling resistance• Less remedial repair work• Improved surface finish

Classification of Admixture :They are broadly classified into the following four groups:1. Modified Lignosulphonates.(MLS).2. Poly-Napthalene Sulphonates (PNS) or Sulphonated

Napthalene formaldehyde Condensates (SNF) orBeta Napthalene formaldehyde Condensates (BNS).

3. Poly-Melamine Sulphonates (PMS) or SulphonatedMelamine-Formaldehyde Condensates.(SMF).

4. Acrylate Polymer Based (AP)Copolymer of carboxylic Acrylic with Acrylic Ester (CAE).Cross Linked Acrylic Polymer (CLAP).Poly-Carboxylate Ethers (PCE)Multi-Carboxylate Ethers (MCE)Poy-Acrylates.

Modified Lignosulphonates (MLS):Lignosulphonates are obtained as a by-product of pulpand paper industry.The modified lignousulphonates arelignousulphonates from which sugars,which causeexcessive retardation,have been removed. The waterreduction capacity of these type admixture is 8-10%.

Poly-Napthalene Sulphonates (PNS):The most widely accepted compounds of this group arethe Poly Beta Napthalene Sulphonates (PNS).Thesynthesis of PNS superplasticizers involves severalsteps.

It begins with sulphonation of molten napthalene withconcentrated sulphuric acid at high tempreture andpressure for several hours,followed by condensation ofthe Beta Napthalene Sulphonate with formaldhyede.It isthen neutralized with a suitable alkali and subjected tofiltration to eliminate any undesirable by-products.This

Superplasticizer is also Known as SNF. The waterreduction capacity of these type admixture is 18-22%.

Poly-Melamine Sulphonates (PMS):The synthesis of PMS superplasticizers also involvesseveral steps.First,formaldhyede reacts with the aminogroups of melamine in alkaline conditions,yeilding anadditional product containing one or more Methyol(CH2OH) groups,depending on the Formaldehyde /Melamine ratio.Sulphonation of one of the Methylolgroups Is then performed using sodium bisulphates underthe same alkaline conditions. polymerization of thesulphonated monomeric units is than initiated by mildheating under slightly acidic conditions.finally when thedesired degree of polymerization has been obtained,thereaction is stopped by increasing the pH values and thefinal product is filtered to eliminate any undesireable byproducts.this superplasticizer is also known as SMF.The water reduction capacity of these type admixture is15-20%.

Poly-Carboxylate Ethers (PCE):Poly-Carboxylate is a common term used for substancewhich are specially used as poly acrylate and multicarboxylate ethers.these are organic polymers bearingcarboxylic groups.several poly carboxylate polymers andin particular poly acrylates have been proposed asSuperplasticizers for concrete since the early 1980s.plyacrylate polymers are prepared by free radical additionpolymerization of acrylic monomers.The water reductioncapacity of these type admixture is 35-40%.

Mechanism of admixtures:General:Cement particles have a strong tendency to flocculatewhen they come in contact with water.even atmosphericmoisture is sufficient to result in flocculation of cement.

This tendency is a result of several type of interactions-Vander waal’s interactions between particles,electrostaticinteractions between particles bearing oppositecharges,and strong interactions involving watermolecules.

The flocculation of cement results in the formation of anetwork of cement particles which trap part of mix waterin the network voids.The water which is held by cement


particles at molecular level is not available for thehydration of the cement particles and for the improvementof workability of the mix.These effects result in thestiffening of the cementitious system.

Following the adsorption of superplasticizers,severalphysico-chemical effects may take place in the cementpaste.Different authors have proposed a variety of effects

o r

mechanisims,to explain the mode of action ofSuperplasticizers.

They are as follows:

1. Lubricating film between cement particles,reducinginter-particle friction.

2. Dispersion of cement particles,releasing the watertrapped within the cement flocs.

3. Change in the morophology of the hydration productswhich contributes to increased workability of the mix.

4. selective blocking of reactive surface sites bysuperplasticizer molecule.

5. Induced electrostatic repulsion between particles.6. Induced steric hinderance preventing particle-particle

contact.

7. Inhibition of the surface hydration reaction of thecement particles,leaving more water to improve theworkability of the mix.

It is likely that more than one of these phenomenacontribute to the fludifying effect of superplasticizers.However there is a broad agreement that following arethe three main mechanisms or actions that explain theaction of superplasticizers:Adsorption:

Superplasticizers act as powerful dispersing agents.Aswith most dispersing agents in aqeous solutions, theyfirst act by being adsorbed onto the surface of cementparticles.A significant portion of the superplasticizers isadsorbed strongly onto cement particles atconcentrations normally used in concrete.Adsorption ofthe negatively charged superplasticizers onto thenegetively charged cement particles is made possibleby the presence of calcium ions that have beensolubilized from cement.

De-Flocculation: De-Flocculation takes place intwo ways:A) Electrostatic Repulsion: The adsorption ofsuperplasticizer molecule on to the surface of cementgrains conveys high negetative surface charges (potential)to all the cement particles.These charges generateelectrostatic repulsion between neibouring cementparticles.The electrostatic repulsive forces overcome theattractive forces between the cement particles and mostcertainly play a role in deflocculating and dispersingcement particles.This type of action is predominant inMelamine (SMF) and Napthalene (SNF) basedsuperplasticizers.B) Steric Hindrance Effects:In addition to theelectrostatic effect, the dispersion of cement praticlesis further assisted by repulsive forces orginating from“Steric Effects” – The adsorbed superplasticizerconstitutes a physical barrier to particle- particle contact,that is, the dangling chains of polymer adsorbed on twoadjacent surfaces entangle forming a physical barrierpreventing particle – particle contact. This helps inpreventing flocculation and results in the dispersion ofcement particles. This type of action is predominant inacrylate polymer based superplasticizers.C) Chemical Interaction: The physical effects uderlyingthe mode of action of superplasticizers, as describedabove, are complemented by “chemical effects”. Thechemical action of the superplasticizers is first manifestedin the adsorption process-for example,sulphonate basedpolymers interact preferntially with aluminate phases ofthe cement,that is,by analogy with sulphonate ions.Inaddition,several types of superplastcizers molecules areknown to inhibit and the growth of hydration products.

References:1. CBD-203.Superplasticizers in concrete- V S

Ramachandran.2. Construction Chemicals- Dr.R V Ranganath3. Concrete Technology-M S Shetty.4. Hand book on Admixtures-V S Ramachandran.

Polycarboxylates(PCE)


ABSTRACTIn the present paper moving aspects of structures aretaken up.

In our daily structural design the structures are assumedto be immovable, and most of structural calculationsare carried out on the basis of static principles. Althoughwe know that a structure always produces such amovement due to loading that is referred to as deformationor displacement, its magnitude is normally too small tobe significant in comparison with the dimensions of thestructure, and its effect on the structural behaviors isneglected, the whole phenomenon being treated asstatic. There are cases, however, where large movementsare actually experienced by our structures due todifferent reasons. Many of them are due to excessiveloading and unexpected instability, often leading tocollapse of the structures. Some other cases are relatedto vibration where resonance of structures with externalagencies such as earthquakes and wind is a keyquestion. Self-excited oscillation sometimes producescatastrophic and very spectacular motion of structures.Controlled motions can be obtained by adopting isolatorsto cope with the effects of earthquakes. Dampers whichare often incorporated in seismic isolation systems arenormally rather still, but motion of tuned mass dampersis sometimes very significant. Structures can bedesigned to be assembled on the ground and thenhoisted to the position. In erection of such structures abig movement is observed as in Pantadome System.Finally those structures which are originally intended tomove are described with examples of rocking stonesand a flying carp.

Keywords: moving structures, collapse, excessivedeformation, controlled motion, earthquake isolation, self-excited oscillation, Pantadome system, tuned-massdampers, pendulum system

UNDESIRABLE MOVEMENTSThere are unfavorable movements which poor structureshave to experience under some undesirable conditions.They are movements due to excessive snow loads,earthquakes, wind, structural deterioration and so on,and those movements have different characteristics dueto the natures of the causes.

Collapsing Movements due to Snow LoadsStructures standing on the principle of arches and domesare sometimes in danger of yielding collapsingmovements due to unstable deformation of thecompressive members.

One of such examples is the dome for a trade center inBucharest which collapsed in January 1963 (Fig.ures.1

WHEN STRUCTURES MOVEKawaguchi, Prof. Mamoru

and 2). The dome had a spherical shape to cover a planof 93.5m in diameter. The dome experienced a huge“snap-through” deformation, or a deformation from convexto concave geometries under the snow load of 2,000 kNwhich was less than 30% of the design snow load.

Another example of this kind is a collapse of the hangingroof of “Palasport” in Milan which occurred in January1985 (Figures 3 and 4). It had a circular plan of 128m indiameter. The presumed snow load on the roof at thetime of collapse was 1.4 kN/m2 while the standard snowload was 0.9kN/m2 . The roof of this velodrome was asaddle-shaped hanging roof that should have moresufficient potential strength, but the collapse was causedby the buckling of the ring beam the section of whichhad been a box section of thin steel plates.

In the above examples the structures must haveexperienced very large movements during the collapse,but no such movements were visually recorded.

There are many other examples of structural collapsedue to snow loads, but observation records of thecollapsing movements are scarce. In general the visualrecords of collapsing movements of large-span roofs dueto snow are difficult to make, since firstly it is not easyto anticipate the time of collapse which often occurs ata lower loading level than in design, and secondly weatherand shooting condition are bad because of snow fallingand snow drift.

Destructive Movements due to EarthquakesEarthquakes make structures produce significantmovements which are often destructive. Different fromthe effects of snow, earthquakes are not loading on thestructures but vibrational motion of the grounds on whichthe structures stand. Therefore the motion induced inthe structures by earthquakes is closely related to thevibrational characteristics of the structures, and whenthe natural periods of the structure are close to those ofthe prevailing ground motion, the motion of the structurescan be destructive. On the other hand this type of motioncan often be controlled by means of vibration technology.The ideal case of such a control is seismic isolation, aswill be described later.There have been so manydestructive motions of structures due to earthquakes,and some of them have been recorded numerically inthe form of acceleration data, but visual records of suchmotions are again very scarce because of the facts thatprediction of destructive earthquakes is again very difficultand that photographers are also in danger of their livesduring the severe earthquakes.

Uncontrolled Movements due to WindIn design of comparatively rigid structures we treat theeffects of wind as static loads. When a structure is soft,


however, we have to take into account dynamic effect ofwind, and motions of the structure due to this effect.Dynamic effect of wind due to disturbance in the windflow itself is sometimes referred to as buffeting or gustyeffect, and resonance of the structure with this effect isoften discussed.

Another and more important effect of wind is vortex-induced vibration, and still more important is self-excitedoscillation or flutter starting from the vortex-inducedvibration. In such a motion the structure takes in energyfrom constant air flow around it to grow the motion untilit becomes catastrophic. The collapse of TacomaNarrows Bridge is explained as the result of suchphenomena (Figures. 5 and 6). In general the magnitudeas well as the mode of self-excited motion is very bigand exceeds our imagination, often being evenspectacular. Such motions are comparatively easy torecord visually, since the time of strong wind can bepredicted, the motion of this kind lasts for relatively longtime and the photographer is not always in a dangeroussituation.

CONTROLLED MOVEMENTSSeismic IsolationSeismic isolation is a technology to control the responseof structures due to earthquake ground motion. Theisolation technology is normally applied in combinationwith energy-absorbing damping systems. The mostpopular seismic isolation system is the laminated rubbershoes that support the structures. However, there areother isolation systems effective to control seismicmotions in more rational manners than laminated rubbersystem, which will be described in this section.

Pendulum IsolatorsA pendulum system is one of the basic methods ofseismic isolation, having the same fundamental principlein common with seismographs. As shown in Figure 7,pendulums used in engineering include (a) simplependulum, (b) physical pendulum, and (c) translationalpendulum.

It is well known that the natural period T of a simplependulum is given as follows with the length of the hangerL, and the gravitational acceleration g.

One advantage of a pendulum seismic isolator is thatthe length of the hanger L is the only parameter governingits natural period, and the mass of the object to beisolated exerts no effect on it at all. Thus, desired periodscan be obtained by simply changing the hanger length.This is the greatest advantage of pendulum seismicisolators compared to laminated rubber seismic isolators

in which the natural period is determined by the massand rigidity of isolation structure.

The natural period is slightly elongated if the amplitudeis made larger. The elongation, however, is minute. Thus,the above equation (1) can be considered valid for allpractical cases. This is another advantage of thependulum seismic isolator compared to the laminatedrubber system, of which the deformability is limited.

Wide selection of materials is available for the hanger.For example, technology for fireproofing has alreadyreached a mature state if steel is to be used. Asdiscussed above, seismic isolators using pendulumprinciple possess considerable merit.

Considering that seismic isolators must also functionas a part of structural support, simple pendulum shownin (a) of Figure7 is obviously difficult to use. Natural periodof physical pendulum shown in (b), on the other hand,fluctuates along with the location of center of mass aswell as the moment of inertia of the system. Thus,translational pendulum shown in (c), whose natural periodis only affected by the hanger length as in the simplependulum, would be appropriate for use as a seismicisolation device.

One possible application of the translational pendulumseismic isolator is for individual floors.

A floor suspended from a girder of a building frame asshown in Figure 8 was adopted for the exhibition roomsof an actual museum for pottery and porcelain wares (inGifu Prefecture, Japan, completed in 2001). The area ofthe suspended floor is about 1,000 m2, and its mass isabout 1,000 tons. Hinges having universal joints are usedfor the upper and lower ends of the hanger. If the hangeris made to be 4.5 m long, Equation (1) yields a naturalperiod of more than 4 seconds, which is consideredsufficiently long for seismic isolation. A series of seismicisolation tests showed that the system was effective tominimize the seismic effects on the floor.

Rocking Pendulum IsolatorsA paddle isolator is based on a rocking pendulumprinciple, the concept of which has a long history. Thefirst example of isolated foundations in Japan wasdesigned by Ryuichi Oka in 1932, as a column having aspherical end at the bottom and connected to thesuperstructure via a spherical hinge at the top. Due torocking motion of the column, the superstructure movesin a trochoidal curve.

This concept, however, was impractical as production ofspherical elements required considerable skill and man-hours, and column design sometimes interfered withoverall architectural planning. In the present designrocking motion of the sphere was resolved into theorthogonal components along the X- and Y-axes on a


plane coordinate. Then, a mechanism was designedwhich assigns the components of the rocking motion inthe directions of X- and Y-axes to the upper and lowerends of a column. Paddle isolator was named after akayak paddle, as the form of the present columnresembles it. As shown in Figure 9, a paddle isolatorconsists of a column provided with “blades” on the topand bottom ends whose curvatures are designed to beorthogonal to each other. This column allows resolutionof any horizontal motion in an arbitrary direction into twodirections, and the isolated part of the building is free tomove in the horizontal direction. Referring to Figure 10,the natural period of a rocking pendulum is determinedby the length of the isolation column L and the radius ofcurvature of a blade R, and can be obtained by Equation(2).

One of the features of the rocking pendulum isolator isthat its natural period is not governed by the mass ofstructure to be supported or any mechanical propertiesof the materials used in the isolator, similar to thetranslational pendulum isolator. On the other hand, thepaddle isolation column may be designed with any length,unlike the translational pendulum isolator. As such,isolating layer may either be placed just underneath thefoundation, or the entire ground floor may be designedas an isolating layer. This enables design of seismicisolators having longer periods, which were conventionallydeemed impossible. In order to confirm the effect of thepaddle isolators, acrylic specimens (shown in Figure 12,the floor panel being 40 cm by 40 cm) were manufacturedand tested. The test results indicated fairly constantnatural periods for paddle isolators, regardless of theamplitude of the given motion or the mass ofsuperstructure. Furthermore, the torsion movement washardly observed even when the mass supported by theisolation layer was largely shifted off the center.

Figure 11 shows the rates of the observed accelerationresponses when the seismic motion based on the recordsof the actual earthquakes were applied to the vibrationtable. As shown, response in the upper part of the isolatinglayer was reduced sufficiently. It was also confirmed thatthe effect is not influenced by the direction of input seismicmotion.

Damping SystemsDamping systems are often used in combination withseismic isolators, but they are of course used bythemselves as well for the purpose of energy absorption.Most commonly used in vibration control are viscous,frictional, hysteretic and tuned-mass dampers. The firstthree of the above dampers control the vibrational motionof the structures by dissipating the energy in the form ofheat, while the tuned-mass dampers transform the energy

of their mother systems into the motion of themselves.So the effect of tuned-mass dampers can be visuallyconfirmed by means of scaled model tests, where thetransfer of motion from the structure to the dampers isclearly observed.

HUMAN-INDUCED VIBRATIONSoft footbridges often produce significant vibrationalmotion that is induced by the movement of pedestrianscrossing the bridges. It is interesting to note that whenthe movement of the bridge, especially the transversehorizontal component of which is big enough to be feltby the pedestrians, they are apt to try to securethemselves by tuning their steps to the period of themotion of the bridge, resulting in amplification of the bridgemotion. Vibration of Millennium Bridge in London was atypical example, which was solved by incorporating apassive damping system in the bridge.

DESIGNED MOVEMENTSPantadome SystemStructures are sometimes designed to move duringconstruction for safe, efficient and economical erection.A patented structural system called ‘Pantadome System’was developed by the author with such an idea for arational construction of spatial structures, and it wassuccessfully applied to the structure of World MemorialHall completed in Kobe in 1984. Pantadome Systemhas since been applied to the Sant Jordi Sports Palacein Barcelona, the National Indoor Stadium of Singaporeand some important structures of wide spans realized inJapan. The principle of Pantadome System is to make adome or a domical structure geometrically unstable fora period in construction so that it is ‘foldable’ during itserection. This can be done by temporarily taking out themembers which lie on a hoop circle. Then the dome isgiven a ‘kinematic mechanism’, that is, a controlledmovement, like a 3-D version of a parallel crank or a‘pantagraph’ which is popularly applied to drawinginstruments or a power collector of an electric car (hencethe name, ‘Pantadome’). By ‘folding’ the dome in thisway, the constituent members of the dome can beassembled on a lower level. The assembly work is thusdone safely, quickly and economically, since it can becarried out near the ground level.

Since the movement of a Pantadome during erection isa ‘controlled one’ with only one freedom of movement inthe vertical direction, guying cables or bracing memberswhich are indispensable in conventional structures toassure their lateral stability against wind or seismic forcesare not necessary in erection of a Pantadome structure.The movement and deformation of the whole shape ofthe Pantadome during erection are three dimensionaland may look spectacular and rather complicated, butthey are all kinematically determinate and easilycontrolled. Three kinds of hinges are incorporated in the


Pantadome System which rotate during the erection.Their rotations are all uni-axial ones, and of the mostsimple kind. Therefore, all these hinges are fabricated inthe same way as normal hinges for usual steel frames.

Rocking StonesRocking stones are stones originally created by Naturethat are movable by human power, or at least looking tobe movable. Here is an example of artificial rocking stoneof 36 tons that can be moved by a little child. Repetitivepush of the child in tune with the period of the rockingstone brings the stone into a motion of slow butsignificant amplitude.

Flying CarpThe “KOINOBORI” is a Japanese traditional carp madeof fabric which people fly in the breeze in early days ofMay every year to celebrate the growth of children. Thenormal size of a KOINOBORI is 2 to 5 meters in length.

KAZO is a town in the suburb of Tokyo that has beenfamous for its production of KOINOBORI since more thanone hundred years ago. We can still see excellentcraftsmen who hand-paint beautiful KOINOBORIS infactories of KAZO City. In 1988 volunteers of KAZO City,who were members of Junior Chamber International, gotan idea of fabricating and flying a gigantic KOINOBORIof 100m to advertise their city to the world. However,they did not know how to produce such a huge carpproperly. They did not even know if such a monstrousfeature might “fly” in the air at all.

The author had an opportunity to assist them byestablishing the technical basis for the possibility of flyingthis gigantic fabric fish in the air. He showed by theoryas well as experiments that a huge KOINOBORI couldbe designed to fly in the breeze of the same wind speedat which normal carps fly. By this design theory andstructural details a huge KOINOBORI was designed, itwas fabricated by the voluntary members of KAZO City,and finally it succeeded to fly elegantly in the sky. Sincethen flying of the Jumbo KOINOBORI became an annualevent of KAZO City, being celebrated in the beginning ofMay every year.

CONCLUSIVE REMARKSMoving aspects of structures have been described.Although structures are normally regarded stationary,there are many cases where structures movesignificantly. The most undesirable motion of a structureis the one due to collapsing effects of external agenciessuch as snow, earthquake, terrorism and deteriorationof materials.

Structures sometimes produce uncontrolled motion dueto wind effects The most dramatic motion is observedwhen structures show self-excited vibration often startedby Kármán Vorticies as in the catastrophic example ofTacoma Narrows Bridge. Since the task of structural

engineers is to create strong and safe structures, weshould be aware of those undesirable movements andshould always try to find the means to cope with thosephenomena. Sometimes we can make the motion ofstructures controlled one. This can be achieved by meansof seismic isolation to cope with earthquakes, and generaldampers to cope with other vibrational effects.

We can also design the structures so that theyexperience significant movements in the process ofconstruction for the sake of safety, efficiency andeconomy of construction, as in the example ofPantadome System. Movement is sometimes theintended function to be performed by a structure. One ofsuch cases is an artificial rocking stone of 36tons whichthe author designed to be moved by a little child. Anotherexample is a huge fabric carp of 100m in length that canfly in the breeze, fabricated by volunteers of a small townin the suburb of Tokyo under the technical guidance ofthe author.

Although it is impossible for those volunteers of the smalltown to make a jumbo jet aircraft, they could fabricate acarp which is much bigger than Boeing 747, and fly it inthe breeze of Kasiserslautern in Germany as well as oftheir hometown where they have been playing with it foreighteen years.

Author Affiliation :Mamoru Kawaguchi, KAWAGUCHI & ENGINEERS,[email protected]

REFERENCE1. A. Beles et al (1966), “Some Observation on the

Failure of a Dome of Great Span”, 1st InternationalConference of Spade Structures, University of Surrey

2. S. Montague (1985), “Milan Roof is Total Write Off”,New Civil Engineer, April 25

3. E.B.Farquharson, et al., “Aerodynamic Stability ofSuspension Bridges with Special Reference to theTacoma Narrows Bridge” Bul. Of Univ. WashingtonEng. Exp. Station, No.116, 1949-1954.

4. M. Kawaguchi, I. Tatemichi (2000), “Seismic IsolationSystems and Their Application in Space Structures”,IASS Symposium on Bridging Large Spans; FromAntiquity to the Present, Istanbul

5. M. Kawaguchi, I. Tatemichi (2000), “Characteristicsof A Space Structure Seismically Isolated by RockingPendulums”, IASS-IACM 2000, Fourth InternationalColloquium on Computation of Shell & SpatialStructures, June 2000, Chania, Greece

6. M. Kawaguchi (2003), “Physical Models as PowerfulWeapons in Structural Design”, IASS Symposiumon Shell and Spatial Structures from Models toRealization, Montpellier, September, 2003


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NEWS FROM ACCE(I) HEADQUARTERS1. ACCE(I) HQ conduct the election and elect the

following office Bearers for the year 2009-2011.Mr. Avinash Dhondu Shirode PresidentMr. Hemant Hari Dhatrak Vice President (West)Mr. T. Senthil Nayagam Vice President (South)Dr. M. U. Aswath Secretary GeneralMr. Badarinaath Singri Treasurer

2. The 3rd G C Meeting held on 09.05.2009 hosted byACCE(I) Mysore Centre. Centre also organise theACCE National Resource Meet on WATER ANDWASTE TREATMENT at 09.30 am at Hotel PaiVista, Mysore.

3. The Award Committee & Special Governing CouncilMeeting held on 20th June 2009 at Bangalore andfinalise the awardees for year 2009 as below:

• ACCE SIMPLEX AWARD 2009 for Innovative Design ofStructures other than industrial structure to JunghareDesigners & Consultants, Nagpur for InnovativeDesign of Structures for Junipers Software Pvt. Ltd.,Nagpur.

• ACCE L&T ENDOWMENT AWARD 2009 for Excellencein Construction of Industrial Structure to ShapoorjiPallonji & Co. Ltd., Bangalore for Indian Machine ToolsManufacturer's Association's Bangalore InternationalExhibition Centre on Tumkur Road, Bangalore.

• ACCE BILLIMORIA AWARD 2009 for Excellence inConstruction of High Rise Building to L & T, ECCConstruction Group, Chennai for Construction of UBCity at Vittal Mallya Road Bangalore.

• ACCE SOM DATT AWARD 2009 for Excellence inConstruction of Transportation Project to L & T, ECCConstruction Group, Chennai for Construction ofPanipat Elevated Expressway Project in Haryana.

• ACCE SARVAMANGALA AWARD 2009 for excellencein construction of Civil Engineering projects other thanIndustrial Plant and Transportation Projects to B GShirke Construction Technology Pvt. Ltd., Bangalorefor Excellence in Construction of Vidhana Soudha SouthBlock (Vikasa Soudha) at Dr. B R Ambedkar Veedhi,Bangalore for Karnataka Public Works Department.

• ACCE NAGADI AWARD 2009 for Best Publication (Book)in Civil Engineering to Dr. Nainan P Kurian, Coimbatorefor Shell Foundations – Geometry, Analysis, Designand Construction

• ACCE CDC AWARD 2009 for Best Software Package inCivil Engineering AEC Logic Pvt. Ltd, Hyderabad forSoftware Package for ProEST+ Building 2009

• ACCE L&T FORMWORK AWARD 2009 for Best Use ofFormwork In Civil Engineering to Gammon India Ltd.,Mumbai for Construction of Kaiga Domes at Karwar,Karnataka

• ACCE GAMMON AWARD 2009 for Effective Use ofConstruction Materials/ Systems in ConstructionResulting In National Savings to L & T, ECCConstruction Group, Chennai for Excellence inConstruction of Bangalore International Airport atDevanahalli, Banglaore (Greenfield Project)

• ACCE GOURAV AWARD 2009 for SignificantContributions to Civil Engineering Consultancy to Dr. VV S Rao, Delhi.

Report by Secretary General

NEWS FROM ACCE(I) CENTRESBANGALORE CENTREAGM & AWARDS PRESENTATION: Association of ConsultingCivil Engineers (India) – Bangalore Centre AGM 2009 heldon 22nd May 2009 at Century Club along with AwardsPresentation Ceremony 2009.

Mr. Ajit Sabnis Chairman Welcomed the members and givethe welcome address, Dr, M U Aswath, Secretary Presentthe Annual Report for the year 2008-2009 and Mr. P SDeshpande, Treasurer Presented the Audited Statement ofAccounts for the year 2008-209 and Proposed Budget forthe year 2009-2010.

Dr. M U Aswath, Chairman Awards Committee announcedthe ACCE BLC Awards for the year 2009.

ACCE-SUNDARAM MERIT AWARD 2009 for Best Dissertationby a M.E/M.Tech (Structures) Student from the EngineeringColleges of Karnataka). The awards committee evaluatedand recommended for the award to Mr. Ashoka K C,Dayananda Sagar College of Engineering, BangaloreExperimental Studies on Effect of Metakaolin and Rice Huskash on Strength and urability of Self-compacting HighVolume Fly Ash Concrete.

ACCE–M.R.SRINIVASA IYENGAR MEMORIAL MERIT AWARD2009 for Best Academic performance in the 4thSemester of the Diploma Course in Civil EngineeringDraughtmanship from the Government Polytechnic forWomen, Bangalore Awarded to Kum. MAHALAKSHMI S.

ACCE-NIRMANA NIRVAHANE PURASKARA 2009 for BestDissertation in M.E./M.Tech Construction Technology &Management from the Engineering Colleges of Karnataka.This award has been Instituted by: A N Prakash ConstructionProject Management Consultants Pvt. Ltd., Bangalore. ).The awards committee evaluated and recommended forthe award to Mr. KIRAN L BMS College of Engineering,Bangalore Scheduling of a Construction Project Using Line-of-Balance (LOB) Technique.

The awards committee unanimously decided to give JuryAppreciation Certificate for the good work done by Mr.PRAMOD M D, B M S College of Engineering Bangalore forhis dissertation on “Assessment of Fine A g g r e g a t eObtained from Concrete Debris for Functional Mortars”.

Mr. A N Prakash, A N Prakash Construction ProjectManagement Consultants Pvt. Ltd., Bangalore Present theCitation and Cash Prize to Mr. Kiran L, & Mr. Pramod M D, BM S College of Engineering, Bangalore.


ACCE BLC conducts the Election and elects the followingoffice bearers for the year 2009-2011.Mr. M S Sudarshan ChairmanMr. P Nagesh SecretaryMr. P S Deshpande TreasurerMr. Madhukar B A Managing Committee MemberMr. C H Prakash Managing Committee MemberMr. R K Sunil Managing Committee Member

ACCE(I) Bangalore Centre organising the 1st TechnicalEvening Lecture on “INNOVATIVE PLASTIC FORM WORK”on 2nd June 2009 at the Karnataka Sate Club CricketAssociation (Club House), M. Chinnaswamy Stadium, M GRoad, Bangalore – 560 001.

Mr. M S Sudarshan, Chairman, ACCE(I) BLC Welcomed themembers and delivering the address, Mr. Nagesh P,Secretary, ACCE(I) BLC. Introduce the Speaker, Mr. VictorWarden Vice President- Formuvation Engineers India & Mr.Jigesh Desai President, Formuvation Engineers Indiadelivering the technical talk. Mr. Umesh B Rao, President,ACCE(I) give Presidential Address, Dr. M N Hegde, SecretaryICI-KB giving the vote of thanks.The above programme was sponsored by G M V R FormWork Engineers Bangalore & Formuvation Engineers India.

ACCE(I) Bangalore Centre organising the Technical EveningLecture on “New Road Building Technology” on 15th June2009 at the Karnataka Sate Club Cricket Association (ClubHouse), M. Chinnaswamy Stadium, M G Road, Bangalore –560 001. Mr. John Winters, President, Romix Holdings Ltd,Australia delivered the lecture.

Introduction of “Soilfix“ into India: Romix Holdings Ltd wasestablished in 1996. Today it has its Corporate Offices inHong Kong and Mauritius. Romix produces a Polymer basedproduct SOILFIX, for stabilizing the Base layer for all Roads- Village, City and Highways. Over the past 13 years SOILFIXhas been used in over 20 countries including South Africa,Nigeria, Kenya, The Middle East, Australia, China andEurope. In 2007 Romix entered the Indian market wherewe now have worked with AFCONS, Prestige, PatelEngineering, Bellary Iron Ore Mines, PWD and Rural Roads.

Mr. Winters oversees the operations of Romix in more than30 countries. Mr. John Winters is committed together withour Indian Distributor, Rockwell Road Solutions to "BuildBetter Roads” for India. This will include the establishmentof our First Manufacturing Plant in India in 2009.The above programme was sponsored by RockWell RoadSolutions, Bangalore

MADURAI CENTREThe 10th Annual General-body Meeting of ACCE(I) MaduariCentre was held on 30th May 2009. The following officebearers, who had been elected unanimously, took charge.Chairman Prof.V. MuthuSecretary Er.R.NarendrakumarTreasurer Er.V.MaranManaging Committee Members : Prof.K.ArunachalamEr.L.Ganesh Khanna, Er.N.Essaki, TirunelveliOn June 16th Ar. P. R. S. Sivakumar gave a presentation on“Colours”. The three basic colour schemes namely,Monochromatic, Analagous, and Complementary were

explained with the help of several slides. The reasons forthe difference between colours shown on shade cards andactual application were explained. Hence the need for trialand error method for choosing the most appropriate colourscheme was expressed. Mr. Raghu of Nippon paints talkedabout the various paints available with them which includesodourless emulsion and anti-bacterial emulsion. These arethe only paints to have obtained the approval of IGBC. Thetechnical evening was sponsored by M/s Nippon paints.

MYSORE CENTERAGM was held on 21.05.2009 at 5.00 PM in the departmentof Civil Engineering, Sri Jayachamarajendra College ofEngineering, Mysore. The centre conducts the Election andelects the following office bearers for the year 2009-2011.

Chairman: Prof. C. N. YadunandanSecretary: Dr. M. C. NatarajaTreasurer: Mr. H. N. Vijayavittal

Executive committee members1.Dr. Syed Shakeeb-Ur Rahman2. Dr. V. S. Gajarajan3. Dr. S. N. Karnik

REPORT ON THE ONE DAY RESOURCE MEET ONWATER AND WASTE TREATMENT CONDUCTED ATHOTEL PAI VISTA ON 7TH MAY, 2009.In view of disseminating information regarding the currenttrends in Water Treatments, Sewage Treatment and SolidWaste Disposal, ACCE, Mysore Center organized a novelmeet where leading consulting firms in these fieldspresented their technologies.

The meet was inaugurated by Dr. H.C. Shanth Chandra,Chairman, KPCB, Professor Jagannatha V., Professor(Hudco Chair) SIUD delivered the keynote address anddeliberated on the main principles of current technologiesand ideas in water and waste treatment. He stressed onthe 3-R’s Reduce, Recycle and Reuse and gave details ofdevelopments in India and abroad in this field.

The main participating firms – Murali Shesh, EnviroEngineers, Brook Field Technologies, Leaving Water FineTechnologies and Dwatts presented their processes forsewage treatment like disk filtration and MBR technologiesshowing the advantages of economy, efficiency reduced arearequirements, power saving etc. M/s Leaving Water FineTechnologies also dealt with latest developments in watertreatment.

Two firms dealing with solid waste treatment – M/s SouthernCojen and M/s Renewgen Venture explained the concept ofwaste separation, reduction and pollution free burning forpower generation and brought out the advantages andpotentials of modern solid waste treatment. M/s Paul fromESHQ consultants explain the concept of evaluationtreatment technologies on the basis of carbon trading.

The seminar was well attended and consisted of delegatesfrom KUWS&DB, BWSSB, KPCB, MCC, MUDA, Industriesof Mysore Region, Mysore University, SKUD, SJCE, NIE,Environmental and Civil Engineering Students apart fromACCE delegates.


FORTHCOMING EVENTS1. ACCE Annual Convention, Awards Presentation, AGM

2009 & National Seminar on Urban Architecture,Construction & Engineering – Urban Renaissances(UrbanACE 2009)Date : 24th – 25th July 2009Venue : Bapuji MBA College of Auditorium,

S. S. Layout, DavangereOrganised by : ACCE(I) Davangere CentreContact : Mr. G B Suresh Kumar

Chairman Organising CommitteeACCE(I) Davangere Centre3121/3, First Floor, Bapuji High School Road,Davangere.

Head Quarters : 2, UVCE Alumni Association Building,K R Circle, Bangalore – 560 001.Tel: 91-80-22247466 , Fax: 91-80-22219012

Email: [email protected] Website: www.accehq.net(for more details see page no……..)

2. Workshop on Analysis of case studies (ForensicGeotechnical Engineering)Date : 12th September 2009Venue : Golden Jubilee Seminar hall,

Department of Civil EngineeringIndian Institute of Science,Bangalore – 560012

Contact : Prof. G L Sivakumar BabuSecretary, Karnataka Geotechnical CentreDepartment of Civil Engineering,Indian Institute of Science, Bangalore 560012Email: [email protected]: 80-22933124.

3. National Seminar on “Green Structures forSustainability”Date : 10th – 11th October 2009Venue : The Institution of Engineers (India) Building,

Allahabad Local CentreContact : Prof. Y P Gupta, Technical Advisor &

Chairman, ICI-ALCA-148 Mehdauri Colony,Allahabad – 211 004. UPTel: 91- 94152 39737 (M)Tel/Fax: 91 5322545620Email: [email protected]

4. National Seminar & Exhibition on RecentDevelopments in Design and C o n s t r u c t i o nTechnologies (REDECON 2009)Date : November / December 2009Venue : Convention Centre, NIMHANS

Campus, Hosur Road, BangaloreContact : Chairman Organising Committee,

REDECON 2009Association of Consulting CivilEngineers (India), Bangalore Centre,No.2, UVCE Alumni Association Building,K R Circle, Bangalore – 560 001.Tel: 080- 22247466, Tel/Fax: 22219012,Email: [email protected]: www.accehq.net

M. No. Name Place

ACCE (I) MEMBERSHIP ADDITIONSACCE (I) welcomes the following new fellow members,life members, members and associate members. ACCEalso congratulates the members who have beenupgraded to Life/Fel low Members and Senior Cit izenFellow Members.

M.No. Name Place2165-F BORAIAH Banglaore2166-L CHAITANYA K K Bangalore2167-L ANAND N Bangalore2168-M RASHMI B Bangalore2169-M NALANDA Y Bangalore2170-M D G SHIVAKUMAR Bangalore2171-A VECHA VARADARAJULU Bangalore2172-A RAVINDRA V KHANDEKAR Bangalore2173-OAM ECMAS CONSTRUCTION

CHEMICALS PVT. LTD., Bangalore2174-F A DEVENDIRAN Chennai2175-M PRADEEP P Chennai2176-M P SENTHIL KUMAR Coimbatore2177-M R PRAKASH Coimbatore2178-M M THANGAVEL Coimbatore2179-M C RATHNA SABAPATHI Avinashi Tirupur2180-M G SARAVANAKUMAR Avinashi Tirupur2181-L AFZAL HUSSAIN KHAN Hyderabad2182-L SUBHASH C YARAGAL Srinivasnagar2183-L SURESH PAI P Mangalore2184-M K DAMODAR SHENOY Mangalore2185-A JUGUL PAUL SALDANHA Mangalore2186-OAM NITTE EDUCATION TRUST Mangalore2187-F SHAILESH KUMAR JHA Mumbai2188-L R KIRAN Mysore2189-L NIRMALA D B Mysore2190-L ROOPANJALI S Mysore2191-L SATISH R Mysore2192-L PRADEEP M P Mysore2193-L Dr. P S RAGHUPRASAD Mysore2194-L KAMATH GANESH MADHUKAR Nagpur2195-F SONAWANE RAJENDRA SUDAMRAO Nashik2196-L KALE BHAGWAN MADHUKAR Nashik2197-M BOTHRA SIDDHARTH INDRANATH Dahanu-Nashik2198-M PRAKASH H V Chickaballapur2199-A KATAMAREDDI UPPAIAH Kakinada AP2200-A MANISHA SHARMA Udaipur (Raj)2201-M KIRKI ORI Arunachal Pradesh2202-OAM POST TENSION SERVICES

INDIA PVT. LTD. Vadodara2203-F SAYED BURHANUDDIN SHUTTARI Aurangabad MS2204-F C K RAVINDRANATHAN Bangalore2205-F H N NIRANJAN Davangere2206-F R C RAJASHEKARAPPA Davangere2207-F C VIRUPAKSHAPPA Davangere2208-F ARAVIND H B Davangere2209-F S K SHIVAKUMAR Davangere2210-F M SHARANAPPA Davangere2211-F I P EKORAMARADHYA Davangere2212-F C CHANDRAPPA Davangere2213-L RAVIKUMAR S Davangere2214-L B S RAVI Davangere2215-L MANJUNATH S Davangere2216-M NAVEEN KUMAR K V Davangere2217-M SHIVAKUMAR B E Davangere2218-M SHANTHAMURTHY G B Davangere2219-M K A NAGAAJA SETTY Davangere2220-M A B RAVI Davangere2221-L K G SURESH Davangere2222-F ABY PAUL Bangalore2223-F K PUTTAIAH Bangalore2224-M PRAKASH S CHINIWAL Bangalore

Continued on page 58


PROFESSIONAL DIRECTORYDAT ENGINEERS INDIA PVT. LTD.C2C in Civil Engineering275/B/10, 19th Main, 10th Cross, Rajajinagar 1st ‘N’ Block,Bangaiore-560 010. Tel/Fax : 080-23522610E-mail : [email protected]

DESIGN CONSULTANTSConsultants for Shells, Space Structures, Rehabilitation andRetrofitting of Structures, Industrial Structures and MachineFoundations, 504, 10-B Main, First Block, Jayanagar,Bangalore-560 011, (India). Tel / Fax : 91-80-26561134E-mail : [email protected]

JUNIPERS SOFTWARE PVT. LTD.(Software Unit of Junghare Designers & Consultants)Project Management, Heavy Industrial Consultants,Architecture, Interiors, Rehabilitation,2, I T Park, PARSODI, South Ambazari Road, NagpurMaharashtra – 440 010 Tel 91-712-2243751/6570252Fax: 91-712-2248452 Email: [email protected]

KAREKAR & ASSOCIATESArchitects, Interior Designers & Structural EngineeringConsultants, 40, 1st Floor, New BEL Road, RMV 2nd StageMSR Nagar, Bangalore - 54. Phone : 91-80-23600909Fax:91-80-23607255 E-mail : [email protected]

KESHAV & ASSOCIATESConsultants, Structural Designers Project Managers, Valuers andQuality ManagersNo. 397, 1st & 3rd Block, 20th Cross, Jayanagar, Bangalore-11Tel/Fax : 26631725 E-mail:[email protected]

InCiCon-AGInnovative Civil Engineering Conclave1400, 2nd Floor, 41st Main, Kanakapura Road, Sarakki Gate,J P Nagar 1st Phase, Bangalore – 560 078. Tel: 91-80-22447700,Fax: 91-80-22446976 Email: [email protected]

A. N. PRAKASH CONSTRUCTION PROJECTMANAGEMENT CONSULTANTS PVT. LTD.‘Vishwakarma’, 491, 2nd Floor, East End Main Road, 9th Block,Jayanagar, Bangalore-560 069 Tel. : 26639780 4 LinesE-mail: [email protected]

POTENTIAL SERVICE CONSULTANTS (P) LTD.‘Suraj Ganga Soft Park’, Ground Floor, 34, 1st Main,3rd Phase J. P. Nagar, Bangalore - 560 078.Tel : 91-08-26493122/23/24 Fax: 91-08- 26493217E-mail: [email protected], [email protected]

M.S. RAMASWAMYChartered Engineer, Principal Consultant,M/s M.S.R.Consultants, Heavy Engineering, Design, Architecture insince 1980, Interiors, Project Management & Services Consultants,15/1, Sir Krishna Rao Road, Basavanagudi, Bangalore- 560 004..Tel: 91-08-26567675 Fax: :91-80-26569069E-mail: [email protected]

S.P. SRINIVASANMadurai ES Consultancy Services Private LimitedIndustrial Structures, Bridges, Prestressed, Concrete,Chimneys, Silos37/17, West Masi Street, Madurai-625 001.Tel/Fax : 0452-2348275 E-mail: [email protected]

RANGANATH & ASSOCIATESNo. 533, 7th Main, Sadashivanagar, Bangalore-560 080, (India)Tel. : 98450 19807 E-mail: [email protected]

MACSEDES CONSULTANTSCivil, Structural & Geotechnical Engineers,7/6, II Cross, Palace Cross Road, Bangalore-560 020.Tel: 23366398 (M) 98455 11569 E-mail :[email protected]

B.R. RAMESHASEACON - SERVE, Structural, Electrical & Allied Consultancy Services,18, Ratnavilasa Road, Basavanagudi, Bangalore-4.Tel/fax: 41204459 E-mail : [email protected]

SPARTAN ASSOCIATESK.N. NARAYANA IYENGAR,Chartered Engineer Regd Valuers, Consulting Engineers,26, Jyothi Mansion, 5th Cross, Malleswaram Circle,Bangalore-560 003. Ph: 41280764/23446027E-mail: [email protected] www.valuers.in

SUNDARAM ARCHITECTS PVT. LTD.Architecture, Engineering, Planning, Interiors, Services#19, Kumara Krupa Road, Bangaiorc-560 001. IndiaTelephone : 22380701 / 22380702 / 22380703Fax : 080-22252339 Email: [email protected]

SUPARNA ASSOCIATESConsulting EngineersWest of Chord Road, 633, 2nd Block, 3rd Stage,Basaveswaranagar, Bangalore-560 079.Phone: 23222238/23226576E-mail: [email protected] / [email protected]

S. RATNAVELSCEBA CONSULTANCY SERVICESRoads, Rehabilitation, Restoring Geotechnical, Turnkey Projects,Penthose, Bougainvillae106, P. T. Rajan Road, Madurai - 625 014Tel: 0452-2522555 / 2522455 E-mail: [email protected]

UMESH B. RAO & CO.Industrial Structures, Coal handling Structures, Power Plants,Process Piping and Equipment foundations Tiffany’s Annexe,2nd Floor, 23, Grant Road, Bangalore-560 001.Tel : 22240359/22240360 Fax:91-80-22213770 Tlx:845-8955E-mail : [email protected], [email protected]

L BALAJIB.E., M.I.E., F.I.V., M.I.S.E., M.I.C.A., M.I.C.I., P.G.D.G.S.V., M.B.A.Professional Engineer (India) , Registered ValuersC-1/433/99, Panel Valuer for Banks, Plot No. 11, SBI First Colony,3rd Street, (Behind Reliance World), By-pass Road, Madurai-625010Tel: 0452-4375336, 2383988, (F) 4373367/9842868351

S. PARAMESH BABUCSN Engineers & Contractors, No. 37, 6th Cross Road, Azad Nagar,Bangalore - 560 018. Tel : 26748859, 9902957368 E-mail : [email protected]


RNI No. KARENG/2002/9245 - Registrar of New Papers for India

Printed and published by Dr. M.N. Hegde on behalf of the Association of Consulting Civil Engineers (India) and printed at Vijayanataraj Printart Industries,S.C. Road, Basavanagudi, Bangalore – 560 004 and published at 2, UVCE Alumni Association Building, K R Circle, Bangalore – 560 001 Editor: Dr. M.N. Hegde

ACCE(I) thanks the following patrons for theirgenerous contributions towards the creation of aPermanent Fund for publishing this Bulletin

THANKS TO PATRONS

ADARSH DEVELOPERSBuilders of Aesthetically Designed and Quality, Luxury Apartmentsfor Modern Living Standard,10, Vittal Mallya Road, Bangalore-560 001. Tel : 080-41343400Fax : 080-41343777 Web: www.adarshdevelopers.comE-Mail : [email protected]

CHAMUNDESHWARI BUILD TECH PVT. LTD.No. 2438, Kumara Krupa, Opp. Bangalore Vihara Kendra, 9th Main,BSK 2nd Stage, Bangalore-560 070. Tel. : 26764974, 26764403/05Fax : 26762978 E-mail: [email protected]

EON DESIGNERSArchitects, Consulting Engineers & Interior Designers35-B, Vasavi Colony, Behind Vikrampuri, Secunderabad-15.Tel/Fax : 040-27847847 E-mail : [email protected]

HYGRADE STEEL PVT. LTD.Manufacturers, Torkar i , A/85, 31st Cross, 7th Main,Jayanagar,Bangalore-560 082. Tel : 26546384 , Fax : 080-26545952E-mail : [email protected]

MADHU INDUSTRIESManufacturers of Steel Doors & Windows with ISI Mark & UPVCDoors & WindowsNo. 30, Pillagaganhalli, Gottigere, Bannerghatta Road, Bangalore -560 083, Tel : 28429778 / 779,Fax : 28429780 Email : [email protected]

MEGH STEELS PVT. LTD.Distributors “TATA Structura” and Dealer in Iron & Steel,A/85, 31st Cross, 7th Main,Jayanagar, Bangalore-560 082.Tel : 26546384 , Fax : 080-26545952 Mobile : 9845013513E-mail : [email protected]

M/s. NAGARJUNA CONSTRUCTION COMPANY LTD.Nagarjuna Hills, Hyderabad - 500 482 Andhra Pradesh, India.Tel : 22224328, 22226214, Telex : 0425-6914 Grams : BuildwellNagarjuna-Where Quality is Trac

NAGADI CONSULTANTS PVT. LTD.Committed to Reliable Accurate and Professional Service,Regd. Head Office : 1014, 1st Main, IV Block, Rajajinagar,Bangalore-560010. Tel :23303007, 23156076E-mail : [email protected]

SBS ASSOCIATESEngineers and Contractors, Class I Contractors in Karnataka PWD795/E, 3rd Cross, ‘A’ Main, Vijayanagar, Bangalore - 560 040.Tel. ; (R) 23356839

SHRI B. SUNDARAMURTHY44/4, 4th Main Road, Malleswaram, Bangalore-560 055.Tel : 23348725 E-mail: [email protected]

TECHNOART CONSTRUCTIONS PVT. LTD.Mayaventure (P) Ltd. Southend Road, Above Canara Bank,3rd Floor, Basavanagudi, Bangalore – 560 004.

THE DESIGNERS AND BUILDERSH.K. Nanjunda Swamy, Consulting Engineer and Partner20/1, II Floor, III Cross, Chikkanna Gardens Road, Shankarapuram.Bangalore - 560 004. Tel : 41127098 Tel/Fax : 26521379

UNITED PRECISION ENGINEERS PVT. LTD.Engineers and Contractors67, ‘Lavina Cour ts’, I Floor, 102, 8th Main, 7th Cross,RMV Extension, , Bangalore - 560 080Tel/fax : 23612825/23618965 E-mail : [email protected]

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Continued from page 54

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Vol. No. 8 No. 4 QUARTERLY

ofAssociation of Consulting Civil Engineers (India)

BULLETINAPRIL - JUNE 2009

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