JURUTERA, October 20068

1. INTRODUCTION The Putrajaya Convention Centre is

located in Precinct 5 of the FederalAdministration Centre of Putrajaya. It issituated on the top of ‘Puncak Selatan’and has a commanding view of theB o u l e v a rd. The Putrajaya ConventionCentre was completed in April 2003 at acost of approximately RM600 million.

The Putrajaya Convention Centre hasa total area of 135,000 m2 inclusive ofbasement carparks and multi-levelconvention facilities at higher levels. ThePlenary Hall is on the 1s t Floor andsurrounded by a ring of galleries, bothVVIP and VIP lounges, a viewing deckand a conference hall. The Head of StatesHall is located on the ground floor,surrounded by VVIP meeting rooms andlounges. The lower ground mezzaninefloor has meeting rooms, a re c e p t i o na rea, administration and maintenanceoffice. On the lower ground floor, thereare meeting rooms, a restaurant and acolumn-free banquet hall that can host a2,600 seated silver service dinner.

P e runding Mahir Bersatu Sdn. Bhd. isthe concept engineer for the PutrajayaConvention Centre and was subsequentlyassigned to be the Checking Engineer forPutrajaya Holdings Sdn. Bhd.

Upon the completion of the tenderexercise, IJM Corporation Sdn. Bhd. (IJM)was awarded the ‘Design and Build’ forPutrajaya Convention Centre. SinclairKnight Merz Engineering Sdn. Bhd.(SKM) was then appointed by IJM as thecontractor’s consulting engineer.

2. CLIENT REQUIREMENT /BUDGET

Putrajaya Holding Sdn. Bhd., theEmployer of this project was given a taskto complete this project in time for the 11th

Organisation of Islamic Conference (OIC)in October 2003. This commitment tohost this conference resulted in a 22months design and build contract.

The brief from the Employer requirednot only a state-of-the art world classc o n f e rence centre, but also an iconbuilding, which can be a landmark forthe country. Being sited on top of thehighest hill is the Federal Administration

Centre of Putrajaya, so nothing less thanan icon building justifies its position.

The brief also re q u i red a 2,800numbers of uninterrupted view seatingat the plenary hall, a 70m column-freebanquet hall below the plenary hall and aHead of State conference hall in between.This offered a challenge to the StructuralEngineer and the Contractor.

How to achieve client’s requirementand budget

With thorough understanding of theclient’s brief and needs, the team appliedits local knowledge, tailored solutions anda highly skilled team with leadingexpertise in long-span roofing stru c t u re ,to deliver the project. The teamconceptualised using the radial armstogether with compression ring beam andgrillage beams to create a 70m “column-f ree” banquet hall. The long span

geometrically complex roof stru c t u re overthe Plenary Hall was conceptualised as a“Spine Truss” spanning across the North-South direction.

Working together with the architectHijjas Kasturi, Perunding Mahir Bersatu

Sdn. Bhd. produced the conceptualdesign and drawings with poundage fortender. Prior to the tender, the quantitysurveyor worked out the pre l i m i n a r yestimated cost plan of the buildings forour client Putrajaya Holdings Sdn. Bhd.

Seven (7) tenderers were pre - q u a l i f i e dand a competitive bid was held. Finally,IJM won and the tendered sum was closeto the estimated budgetary cost submittedearlier by Putrajaya independent quantitys u r v e y o r. The client Putrajaya HoldingsSdn. Bhd. was satisfied that the column-f ree Banquet Hall, uninterrupted view ofthe Plenary Hall and budgetary cost met their re q u i re m e n t .

3. SIGNIFICANCE OF THEPROJECT TO THE COMMUNITY

The Malaysia Government re c o g n i s e dthe impact that the hosting of majorevents can have on export earnings. By

The Design and Construction of PutrajayaInternational Convention Centre.....................................................................................................................................................................................

By: Engr. Chong Thin Hooi, M.I.E.M., P.Eng. and E n g r. Lau Kok Loong, M.I.E.M., P.Eng.

C O V E R ST O RY

The stunning Putrajaya Convention Centre - A spectacular iconic structure for Malaysia

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hosting and attracting major events likeO rganisation of Islamic Congress (OIC) inMalaysia which attracted tourists andtheir important tourist dollars.

Besides tourism, this major project isvery significant to the MalaysiaGovernment, as an Islamic country takingthe leading role. It generates closecooperation, bilateral trades and smartpartnerships especially within the Islamicworld. Some of the Malaysia companieshave gone off s h o re and are working in theMiddle East countries and Sudan.

On the local front, this mega projectdelivered within 22 months to meet OICdeadline, proved the ability of Malaysianconsultants and contractors to deliver“fast track” mega projects. Economically,it activated the construction industriesand created employment for the localindustries.

The completed Putrajaya ConventionCentre did become an icon building asp romised and the 10t h OIC wassuccessfully held. This project has madethe country proud not only because thePutrajaya Convention Centre hasachieved state-of-the-art world classstandard and also it was completed withhigh quality within a re c o rd - b re a k i n gtime of 22 months.

The completion of the PutrajayaConvention Centre on time and onbudget has in a way made known to therest of the world the capabilities of theMalaysian construction industry as awhole. The design by the Architect wasstunning and has off e red a lot ofchallenges to the structural engineer andthe construction team, which wereovercome professionally and skilfully.

The completed Putrajaya ConventionCentre is a world class venue hostingmajor conferences, exhibitions, meetingsand banquet. Its position has also madethis monument a tourist attraction.Visitors can get a commanding view ofthe boulevard and the lake.

4. ENGINEERING ASPECT4.1 FOUNDATION

The main building is supported by thre eseries of radiating circular columns, ofwhich the diameter of the concentric ringsa re 70m, 100m and 130m, re s p e c t i v e l y.

The platform level of the mainbuilding is at RL +60.0m and the building

is founded on hard material(decomposed shale) except at a smallportion at the outer ring where theg round is filled. A raft foundationbearing on hard material was designed tosupport the building and at the filledground, bore piles were used. This finalposition of the main building wasdetermined after a value engineeringexercise was carried out by the conceptengineer, Perunding Mahir Bersatu Sdn.Bhd. The main building was shifted sothat most parts of the foundation is sitedon hard material.

The raft foundation is shaped like a‘doughnut’ and the thickness varies from1.50m to 2.25m. The outer diameter is

108.0m and the inner diameter is 58.4m.The inner space is a non-suspended slab.The shape adopted is most efficient toresist the ring tension force from theoutward push of the rake column.

The analysis of the raft was carriedout using the finite element analysis.(Typical results and reinforcement detail,in stress diagrams are shown in Figure 1and 2).

As the tension ring forces are alsocircular, the reinforcement is also alignedin a circular pattern. This was achievedby rolling the bar to the re q u i re ddiameter.

The total volume of concrete for themain raft is 12,800m

3and casting was

Figure 1: Raft – Hoop Tension – kM/m2

Figure 2: Raft – Circumferential Bending Moment – kNm/m

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divided into 8 segments. Each castingwas completed in about 12 to 18 hours.Thermal insulation using polystyre n esheets and sand bedding was providedafter casting.

4.2 STRUCTURAL SYSTEM The main building consists of 6 levels

of functioning space: -(a) Lower ground (on the raft, housing

the Banquet Hall);(b) Ground Floor (Head of States Hall);(c) 1s t Floor (main entrance to the

Plenary Hall and meeting rooms);(d) 2nd Floor (Plenary Hall and meeting

rooms);(e) 3rd Floor (Plenary Hall, meeting

rooms and viewing decks); and (f) 4th Floor (Mechanical rooms).

The shape of the building is circularhence the structural grid is also circularon plan. The inner ring is 70m indiameter, the middle ring is 100m and theouter ring is 130m. The inner 2 rows ofcolumns (Ring A and B) were 2.0m indiameter and the outer most row (RingC) consists 900mm2 columns.

The lower ground floor housed thec o l u m n - f ree Banquet Hall. The spanbetween the column is 70m and abovethe Banquet Hall is the Head of Stateshall and the Plenary Hall. To support theloadings from the Plenary Hall, aninnovative radiating portal frame (F1frame) was developed (Figure 3). The F1frame is part of the inner most ro wcolumn (Ring A). The horizontal memberof the F1 frame reached out 20m towardsthe centre. The depth of the horizontalmember was 3.9m. All the horizontalmember of the F1 frame stop at the

c o m p ressing ring beam.Within the compre s s i o nring beam (900 x 2700)was a system of grillagebeams 250 x 2000mm(30m diameter)

The analysis of the F1frame was carried outusing finite elements. Thedesign criteria was notonly for strength but alsothe dynamics acceptancecriteria, this will beelaborated in the sectionbelow.

Above the ground floor the structuralsystem consisted of composite columns,s t ructural steel frame and re i n f o rc e dc o n c rete composite slab with shearconnectors. The steel beam was on aradial and circumferential arrangement.The majority of the beams wereconstructed of Grade 43 steel built-upsections (using platethickness up to40mm) and UB steelbeams of up to388kg/m, actingcompositely with theconcrete floor slab.

The outer mostrow column (Ring C)stopped at the gro u n dfloor and the inner ro wcolumn (Ring Aand B)continued to the ro o fat 15° inclinationo u t w a rd from first

floor onwards. The columns were compositecolumns with steel plate with thickness fro m20mm to 40mm infilled with concre t e .

The design for structural continuity at thecolumn had created a challenge. A ninnovative design was carried out on thecolumn node using the STRAND 7 pro g r a m .A typical beam to column connectionmodelling is shown in Figure 4. To achieve arigid connection between the radiating beam,the steel column was fabricated into twohalves and the radiating beam slotted inbetween and welded. (Refer to Figure 5).

Each of these column nodes weigheda p p roximately 10 ton and were fabricatedo ff site. A 200T capacity crawler cranewas used to erect the nodes.

For the erection of the steel member, oneunit of 150T and 200T capacity crawler cranesand four tower cranes with 2.5T tiploadsw e re used. Erection of beam was done insuch a way to form a square closed loop forstability of the stru c t u re .

Putrajaya Convention Centre construction - Night View

Figure 3: F1 Frame - Ground floor

Figure 4: Column Node

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The Plenary Hall was formed usingbuilt-up steel beam raked and shaped in two(2) directions. Precast planks with stru c t u r a ltopping were used to form the seats.

4.2.1 ROOF The roof structure is unique with its

complicated geometry and long span.The shape of the roof resembles a‘p e n d i n g’ which is a buckle worn inMalay weddings. The spine tru s sspanned 90m and had a depth varyingfrom 3.60m to 7.50m. This spine trusssupported the centre roof, inner roof andpart of the outer roof (refer to Figure 6).

The spine was supported by ‘CrabClaw’s at either end. Each ‘Crab Claw’transfered the load to four columns. Theroof structure was modelled using thefinite element program STRAND 7. Themodel was 3-dimensional representingthe entire roof including the ‘Crab Claw’support.

S u fficient access elements wereprovided for easy maintenance of thebuilding and services, considering clearspan and height.

The fabricationand erection of theroof truss was mostchallenging as itinvolved extensivewelding and tightdistortion contro l .A high degree ofaccuracy in fabrica-tion was re q u i re dsuch that theindividual compo-nents were alignedp roperly duringe rection. In order tocatch up with thetight constru c t i o nschedule, thefabricator had top roduce 300 tons ofsteel per week.

The mostchallenging in thee rection pro c e s swas the erection ofthe spine truss. Thespine truss wasanalysed in stagesto re p resent thesequences of

erection supported by temporary towers.The temporary towers were 55 m. (Referto Figure 7).

4.2.2 DESIGN FOR DYNAMICS One of the most challenging technical

aspect of the project was the harmonics of thebuilding. In recent years vibrations due tohuman activities have created serviceabilityissues in health clubs, gymnasiums, stadiumsand even office buildings. These vibrationsa re annoying to the users.

Three factors have given rise to theseproblems: -(a) increased human activities such as

aerobics and audience participation;(b) decreased natural frequency because

of increased floor spans and designwhich has been pushed towards the limit;

(c) d e c reased damping and mass inbuilding construction.In this project (a) and (b) were the

prevailing factors.The F1 frame which supported the

plenary hall was checked for dynamicsacceptance. The audience in the plenaryhall must feel comfortable during all

events. The span of the F1 frame which is70m and being the support for the entireplenary hall loadings had indeed createda challenge to the design team.

4.2.2.1 DESIGN METHODOLOGYFOR DYNAMICS BEHAVIOUR

The stru c t u re was first tuned to achievea natural frequency of 5Hz, thereafter adetail analysis using the STRAND7p rogram was carried out to determine theaccelerations. The results were checkedagainst the National Building Code (NBC)of Canada for compliance. The NBC has seta limit of 4% to 7% g for the expected usagei.e. rhythmic activities. (The acceptancecriteria are shown in Table 1). After a seriesof iteration the design team was able tocontain the accelerations within the limits.

In the modelling of the structure thefollowing assumptions were made: -(i) The mode of vibration of concern

was the vertical components.(ii) The floor vibration was induced

primarily by human traffic.(iii) The forcing frequency was between

1.5 and 3.0Hz.(iv) The maximum dynamic load was

0.375kPa. (Refer to Table 2)(v) Damping 10%.

5. CONSTRUCTIONMETHODOLOGY

The foundation system for PutrajayaConvention Centre was a re i n f o rc e dconcrete raft foundation. The thickness of

Figure 5: Plate Girder welded into half of Column Steel Node

Figure 6: Roof Truss – Wire Frame

Figure 7: View of Temporary Steel Support forSpine Roof Erection

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the raft foundation varied from 2.50m to1.50m. The total volume of the concreteraft foundation was approximately 1 2 , 8 0 0 m3 and the casting of the raftfoundation was divided into eightsectors. The concreting pour of eachsector of the raft was appro x i m a t e l y1,500m3 and was casted within 16 to 18hours continuously, commencing in thelate evening till early the next morning.

The column from basement up toground floor was constructed in concrete.The ground floor structural systemconsists of conventional re i n f o rc e dconcrete frame, compression ring beam,grillage beams and slabs which werecasted in situ.

F rom the ground floor up to the ro o f ,the columns raking at 15% angle weremade up of composite circular steelsections infilled with concrete. The columndiameter of 1,400mm was rolled from steelplates of thickness varying from 20mm to40mm. Shear connections of 19mm and100mm long were provided thro u g h o u tthe length of the column. At the beam-to-column junction, some of the plate gird e rbeams were punched through the columnto create a rigid moment connections. Theroof structure was unique withcomplicated geometry and long span.Fabrication of the truss connectionsespecially the “Crab Claw” end framesupport for the central roof was most

challenging as it involved extensivewelding and right distortion contro l .

6. SIGNIFICANCE OFENGINEERING SOLUTION

The significance of some of theengineering solutions was to meet there q u i rement of a 70m column-free banquethall supporting the Head of State Hall anda Plenary Hall of 2800 seating capacity.

In summary, the significance ofengineering solution are as follows: -1. The team devised a sculptural system

of radial arms together with the compression ring beams and grillagebeams.

2. The relocation of the raft foundationof the building along the main boulevard axis by 60m, so as to befounded on rock, demonstrated theutility of value engineering.

3. The long span geometrically complexroof stru c t u re over the plenary hallwas conceptualised as a “Spine Truss” spanning across the North-South axis, supported by “crab claws” ateither ends.

4. The rigid moment connectionbetween the plate girder beam and column node was an innovative engineering solution.

With the concept developed, thecomplex mega building was then

simplified with the load path clearlydefined and analysed to provide soundengineering to a major project.

7. CONCLUSION The completed Putrajaya Convention

Centre is not just a landmark but an iconbuilding in the Federal AdministrationCentre of Putrajaya.

The teams of engineers, arc h i t e c t ,p roject managers and contractor havebeen delighted with the way in which theideas that the team developed have beentransformed on site at Putrajaya.

The completion of PutrajayaConvention Centre on time and onbudget has not only made the MalaysianGovernment proud but has also shownthat local contractors and engineers areable to deliver a mega project withintwenty-two months.

It has become a masterpiece, a marvelof engineering and the pride and glory ofthe Malaysian engineering sector. ■

Table 1: Acceptance criteria

Occupancies affected by the vibration Acceleration limit, percent gravity

Office and Residential 0.4 to 0.7

Dining, Dancing, Weight Lifting 1.5 to 2.5

Aerobics, rhythmic activities only 4 to 7

Mixed use occupancies housing aerobics 2

Table 2: Design parameters for rhytmic events

Activity Forcing Weight of Dynamic Dynamicfrequency participation load factor loadff wβ psf α αwβ psf

Dancing 1.5 - 3.0 12.5 (27ft2/couple) 0.5 6.25

Lively concert 1.5 - 3.0 31.3 (5ft2/couple) 0.25 7.83or sports event

Aerobics

- 1st Harmonic 2 - 2.75 4.2 (42ft2/person) 1.5 6.30

- 2nd Harmonic 4 - 5.50 4.2 (42ft2/person) 0.6 2.52

- 3rd Harmonic 6 - 8.25 4.2 (42ft2/person) 0.1 0.42

Internal pictures of Putrajaya Convention Centre- Head of State Hall

Internal pictures of Putrajaya Convention Centre- The 2800 Seat Plenary Hall

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