DESIGN DISSERTATIONTOPIC

SKYSCRAPER - MIXED USE DEVELOPMENT AT DHOLERA S.I.R, GUJRAT

SUBMITTED BYMS. KRATI MUKUND SRIVASTAVA

FINAL YEAR, B. ARCH.

PADMASHREE DR. D. Y. PATIL COLLEGE OF ARCHITECTURE, NERUL , NAVIMUMBAI, INDIA.

APRIL 2016

CERTIFICATE

THIS IS TO CERTIFY THAT MS. KRATI MUKUND SRIVASTAVA A FINAL YEAR BONAFIDE STUDENT OF PADMASHREE DR. D.Y PATIL COLLEGE OF ARCHITECTURE HAS COMPLETED TO MY SATISFACTION HER DESIGN DISSERTATION ENTITLED SKYSCRAPER - MIXED USE DEVELOPMENT AT DHOLERA S.I.R, GUJRAT UNDER MY GUIDANCE IN APRIL 2016.

SIGNATURE OF PRINCIPAL SIGNATURE OF GUIDE

PROF. S.V. CHAUDHARI PROF. SANJIV DONGRE

STAMP OF COLLEGE DATE: 1ST. APRIL 2016

ACKNOWLEDGEMENT

I WOULD LIKE TO TAKE THIS OPPORTUNITY TO FIRSTLY ACKNOWLEDGE AND THANK MY THESIS GUIDE AR. SANJIV DONGRE, MY PARENTS FOR THEIR TEACHINGS AND MORAL SUPPRORT, THE GREAT ENCOUREGEMENT THEY ALWAYS GAVE ME IN ACADEMICS AND MY EXTRA CARICULAR ACTIVITIES AND FOR EVERY THING THEY HAVE DONE FOR ME.I WOULD LIKE TO THANK ALL OUR PROFESSORS FOR ALWAYS BEING A CONSTANT SUPPORT FOR ALL OUR ACTIVITIES.I WOULD ALSO LIKE TO THANK MY GUIDE AR.SANJIV DONGRE FOR ALL THE SUPPORT AND HELP WHICH HE HAS GIVEN TO ME WHILE DESIGNING FOR MY THESIS.

INDEX

1. INTRODUCTIONI. DEFINITION OF HIGH RISE BUILDING

II. THE THESISIII. SCOPE OF THE THESISIV. OBJECTIVESV. METHODOLOGYVI. THE SITE

2. DATE COLLECTIONa. PLANNIG AND DESIGNING OF HIGH RISE BUILDING

BASIC PLANNING CONSIDERATIONSBASIC DESIGN CONSIDERATIONS

b. HIGH RISE DESIGN FOR EARTHQUAKE ZONEc. LATERAL LOADS ON HIGH RISE BUILDINGSd. STRUCTURAL SYSTEMS FOR TALL BUILDINGS SYSTEMSe. INSTALLATION OF SERVICE SYSTEMf. FIRE-FIGHTINGg. NET CASE STUDYh. LIVE CASE STUDY

LITERATURE CASE STUDYSPECIAL STUDYANALYSISPROJECT DESIGN DEVELOPMENTCONCLUSION

1. INTRODUCTIONI. DEFINITION OF HIGH RISE BUILDING

II. THE THESISIII. SCOPE OF THE THESISIV. OBJECTIVESV. METHODOLOGYVI. THE SITE

2. URBAN SPRAWL3. VERTICAL LIVING4. MIXED USE DEVELOPMENT5. DEFINE, BENEFIT, CHALLENGES, COST6. CASE STUDIES

LIVE CASE STUDYI. KOHINOOR TOWER

II. PHEONIX MALLIII. LINKIN ROAD, HILL ROADIV. VIVIANA MALL

NET CASE STUDYI. BURJ KHALIFAa. INTRODUCTIONb. STRUCTURAL AND ARCHITECTURE SYSTEMc. CONSTRUCTION d. SERVICES

II. TAIPEI 101III. SHANGHAI WORL TRADE CENTERIV. SWISS TOWER

BOOK CASE STUDYI. DRAGON FLY

II. BIONIC ARCHIII. SWISSIV. KEN YEANG

SPECIAL STUDYI. ECO VILLAGE

II. BAHRAIN WTCIII. URBAN FARMIV. VERTICAL FARM

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CHAPTER -1 INTRODUCTION1.0 INTRODUCTIONMan has always built monumental structures for the gods, including temples, pyramids and cathedrals which pointed to the sky; however, today's monuments, i.e. tall buildings, symbolize power, richness, prestige, and glory. The major difficulty, from the ancient efforts to reach heaven with the Tower of Babel to the world's tallest building - Bhurj Khalifa, has been to overcome the limitations of nature with human ingenuity.

Until the introduction of modem metal frame construction, advent of electricity, fireproofing. and most importantly elevator, tall building actually was not practical, These technological innovations were first utilized in the Home Insurance Building (1885). and by the advances in these innovations, tall buildings become more and more practical,

Today, it is virtually impossible to imagine a major city without tall buildings. Tall buildings are the most famous landmarks of cities, symbols of power, dominance of human ingenuity over natural world, confidence in technology and a mark of national pride; and besides these, the importance of tall buildings in the contemporary urban development is without doubt ever increasing despite their several undeniable negative effects on the quality of urban life.

The feasibility and desirability of tali buildings have always depended on the available materials, the level of construction technology, and the state of development of the services necessary for the use of the building. Therefore, advances in structural design concepts, analytical techniques, and a more sophisticated construction industry, in conjunction with the high-strength lightweight materials have made it possible to construct very tall, much more slender and lightweight buildings at a low cost premium compared to conventional construction.

However, every advance in height comes with a new difficulty and hence the race toward new heights has not been without its challenges as well. Understandably, the increased flexibility makes contemporary tall buildings much more vulnerable to environmental excitations such as wind, which leads to horizontal vibration.The tall buildings are designed primarily to serve the needs of the occupancy, and. in addition to the satisfied structural safety, one of the dominant design requirements is to meet the necessary standards for the comfort of the building users and the serviceability. In this context, since wind can create excessive building motion, the dynamic nature of wind is a critical issue, negatively affecting occupancy comfort and serviceability.

Many researches and studies have been done in order to mitigate such an excitation and improve the performance of tall buildings against wind loads. Hence, different design methods and modifications are possible, ranging from alternative structural systems to the addition of damping systems in order to ensure the functional performance of flexible structures and control the wind induced motion of tall buildings.

1.1 DEFINITION OF HIGH RISE BUILDINGAs the notion of size or appearance of tallness is a relative matter, and not consistent over time and place, it is difficult to define or distinguish the 'tall building', 'high-rise building' or 'skyscraper' just in terms of size. Unfortunately, there is no consensus on what comprises a tall building or at what magical height, or number of stories, buildings can be called tall. The terms all mean the same type of building which is built extremely high - in which skyscraper is a more assertive term. Although the high-rise building has been accepted as a building type since the late 19th century, tall buildings have been constructed since ancient times for several purposes and, therefore, the history of tall buildings is much older than a century.

"A building whose height creates different conditions in the design, construction, and use than those that exist in common buildings of a certain region and period."

-The Council ofTall Buildings and Urban Habitat (CTBUH) Consequently, the use of the terms 'tall building', 'high-rise building', and 'skyscraper' have common associations, and depending on time and place, the concept of height varies in relation to the progress of technology and the desires of society.

1.1.1 BENEFITS OF MIXED USE DEVELOPMENT• Reduced distances between housing, workplaces, retail businesses, and other amenities and

destinations• More compact development• Stronger neighborhood character, sense of place• Walkable, bike-able neighborhoods, increased accessibility via transit, both resulting in reduced

transportation costs1.2THE THESIS 1.2.1 AIMTo design a bioclimalie architecture and integrating plants into skyscrapers for a high rise mixed use development.

1.3 SCOPE OF THE THESIS

• Analysis and incorporating bioclimalic design principles for high rise mixed use development.• Analyzing and using new design techniques

1.4OBJECTIVES

1. To study how architecture contribute to the mixed use development2. To design spaces which enhances the physical and visual interaction and reduce isoJ ation.

3. To design spaces which bring closer to nature and harmony.4. To bring transparency, openness and fluidity of space.

5. Priority to sustainable materials and functional requirements in design, while integrating services to it.

1.5METHODOLOGY

The Fig: 1.1 show the methodology chart for this study. This methodology chart explains the first step, about the study of general information of high rise planning. This includes the components of high rise planning, definition of high rise and its complex services. The next step is the study of high rise planning from various case studies. Then the classification of issues in different aspects is made from the findings. Then the detail study is made for each aspects through different case studies. Finally, the concept for the design is evolved, and progressed towards developing the design.

THE SITE

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GUJARAT ECONOMY

Contribution to the nation 

World’s largest producer of castor and cumin

World’s largest gas based single location sponge iron plant

World’s largest producer of processed diamonds

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RESEDENTIAL AREA

KNOWLEDGE & IT

PUBLIC FACILITIES ZONE

RESEDENTIAL AREA

RECREATIONAL & SPORTS

VIEW

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World’s 3rd largest producer of denim

Asia’s largest grass root petroleum refinery at Jamnagar

India’s largest producer of cotton

India’s first LNG chemical port terminal at Hazira

Gross State Domestic Product Gross State Domestic Product (GSDP) at factor cost at constant (1999-2000) prices in 2006-07 was US$45.30 billion as against US$41.52 billion in 2005-06. The GSDP registered a growth of 9.17% at constant prices in the year 2006-07. Gujarat contributed 6.50% to the Gross Domestic Product (GDP) of India in the year 2006-07. 

Per Capita Income The per capita income at current prices has been estimated at US$915 in 2006-07 (higher than the national average of US$627) as against US$805 in 2005-06, registering an increase of 13.76 % during the year. 

Agriculture Agriculture is well established in terms of natural resources, skilled labour force, enterprising farmers, and the market network. The major food crops in the state are rice, wheat, jowar, bajra, maize, tur, gram, groundnut; while major non food crops are cotton, tobacco, and isabgul. Agriculture accounted for around 18.22% (at constant prices) of the State's GSDP in the year 2006-07. 

Industry The secondary sector accounted for 37.78% (at constant prices) of the State's GSDP in the year 2006-07. Gujarat ranks second in state-wise percentage share of Net Value Added by manufacturing in the factory sector of India according to the Annual Survey of Industries (2004-05). Gujarat has been a front runner in industries including textiles, chemicals, petrochemicals, pharmaceuticals, engineering, oil and gas, ceramics, gems and jewellery, and agro-based products. There are around 202 industrial estates in Gujarat. 

Services 

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The services sector contributed 44.00% (at constant prices) to the State's GSDP in the year 2006-07. Services included trade, hotels, transport, communication, and financial services. 

Social Infrastructure of Gujarat The State is home to India's leading business school Indian Institute of Management, Ahmedabad (IIM-A), and other important institutes such as National Institute of Design (NID), National Institute of Fashion Technology (NIFT), and Entrepreneurship Development Institute (EDI). Apart from the leading institutes the State is also home to 44 engineering institutes and 41 management schools. Further, the State Government plans to establish a shipbuilding university, the first of its kind in the country and it is going be established in Kutch. Besides, the State has a well established health infrastructure including multi-speciality hospitals managed by reputed groups. The State also has multiplexes and multi cuisine restaurants for entertainment. 

Mining As per provisional estimates, the production of agate, steatite and gypsum during the year 2006-07 was 38, 1105 and 156 tonnes respectively. The production of limestone,lignite, bauxite, laterite and dolomite were 22482, 9810, 3214, 262 and 325 thousand tones respectively. The production of clay (others), china clay, bentonite, quartz, silica sand and chalk were 5582, 492, 896, 223, 961 and 199 thousand tonnes respectively. The production of crude oil and natural gas was 6212 thousand tonnes and 3294 million cubic meters respectively during the year 2006-07. 

Power The installed power capacity of the State as on March 31, 2007 was 9561 MW. The total generation of electricity in the State including private sector and central sector share was 61543 MUs in 2006-07 as against 58724 MUs generated during the previous year 2005-06. The total consumption of electricity during 2006-2007 was 41513 MUs as against 38358 MUs in 2005-06. The per capita consumption of electricity during the year 2006-07 was reported to be 1354 units. (as per CEA’s revised formula) as against 1313 units of the previous year 2005-06. 

Natural Gas Gujarat has been one of the earliest oil/gas producing states in the country. Oil and gas reserves in Gujarat are located at Ankleshwar, Mehsana, Tapti High (which is India's second largest producer of gas), Hazira, Bharuch, Gandhar, Dahej, Jambusar, Palej, Kalol, and isolated gas fields around Ahmedabad. Below are figures for gas production in the state during 2001-2006: Gujarat holds the unique distinction of being the only state with more than one gas producer currently. Apart from ONGC Gujarat State Petroleum Corporation Ltd. (GSPC), Cairn Energy and Niko Resources are involved in the process of production of natural gas in Gujarat. Private players including Adani Group and British Gas and public sector companies like GAIL, BPCL, GSPC Gas Company are involved in gas distribution. Hazira and Dahej LNG terminals of Gujarat are the only LNG terminals in the country. LNG terminals are proposed at Mundra and Pipavav. Besides, Gujarat has an extensive transmission network. A Gas grid of around 1600 km is in operation, around 256 km is under construction. 

Infastructure 

1. Airports 

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There are 11 airports under the operational jurisdiction of Airports Authority of India (AAI) International airport: Ahmedabad.Domestic airports: Ahmedabad, Vadodara, Surat, Jamnagar, Rajkot, Bhavnagar, Porbandar, Bhuj,Keshod, and Deesa airports

2. Ports The State has 40 minor and intermediate ports, geographically dispersed across South Gujarat (13 ports), Saurashtra (23 ports) and Kutch region (4 ports) and one major port. Besides this, there are 3 private ports in the State. Kandla is another major port and is under the control of Central Government of India. The total cargo handled by the Kandla Port in quantitative terms has increased from 45.907 million tonnes in the year 2005-06 to 52.982 million tonnes in the year 2006-07, showing an increase of 15.41 % over the previous year (including transshipment). The intermediate and minor ports of Gujarat handled a total cargo of 132.442 million tonnes during the year 2006-07 as against 108.075 million tonnes handled during the preceding year, showing an increase of about 22.54 %. 

3.Roads The total length of roads (except Non-plan, Community, Urban and Project roads) in the State has increased to 74038 km by the end of 2005-06 from 73724 km at the end of 2004-05. Out of the total road length of 74038 km at the end of the year 2005-06, the length of National Highways, State Highways, Major District Roads, Other District Roads and Village Roads was 2867 km, 18702 km, 20707 km, 10503 km, and 21259 km, respectively.

Highlights of Gujarat Economy*

The state accounts for 15.59% of country's investment and 10% of country's expenditure. (Source: www.gujaratindia.com)

Key industries in Gujarat include chemicals and petrochemicals, drugs and pharmaceuticals, dairy, cement and ceramics, textiles, auto and engineering, and gems and jewellery. Further impetus is being provided to Gujarat's economic prosperity by urban, port and SEZ led infrastructure development.

Gujarat's rate of growth of industrial output was 20% in 2006-07

Gujarat is the only state in India which offers investors clear exit options in terms of termination of labour and closure of industrial unit in a Special Economic Zone (SEZ)

Gujarat is an industrially peaceful state with the lowest number of man-days lost in the country.

Gujarat has the largest chemicals industry in the country. It is the leading producer of cement , salt and soda ash in India.

Gujarat has the largest diamond processing industry in the country.

It’s the leading producer of fennel, castor seeds and psyllium husk in the world.

Gujarat has the world's largest grass root refinery located at Jamnagar.

Gujarat is home to Kandla, India's first and largest special economic zone (SEZ). It is also one of India's largest ports with a capacity of 45.9 MMTA (million metric tonnes per annum). Most

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of the bulk traffic (10.8%)of the country is handled from Kandla port which amounts to 150 MMTA.

Gujarat is the first state in the country where ports are being privatised through built-own- operate and transfer (BOOT) scheme. Gujarat has opened the country's first private sector ports Pipavav and Mundra by implementing the BOOT scheme. In addition, the liquid cargo (chemicals) handling port at Dahej is the first of its kind and has been set up as a joint venture.

The state has the highest number of airports(11) in India, including an international airport,in Ahmedabad.

Gujarat has an extensive road network exceeding 74000 km. The Ahmedabad-Vadodara expressway is now open for transportation.

It brought the gas grid in operation and sensitised the nation to the fact that gas can be used to transform lives.

The first state in India to notify the Disaster Management Act.

Gujarat is home to India’s first LNG Terminal located at Hazira. Another LNG terminal is located at Dahej.

2. LOCATION PROFILE

DHOLERA is situated in Ahmedabad district in the Gulf of Khambhat

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Dholera is in proximity with the coastal line. It is covered by water faces on three sides, namely, on the east face by Gulf of Khambhat, on the north side by Bavaliari creek and on southern side by Sonaria creek.

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Proximity to Ahmedabad has provided Dholera a strong locational advantage with a vibrant manufacturing base and investment scenario The project is spread over an area of 35,000 hectares. The processing area which is proposed is 14,000 hectares and rest is non- processing zoneLocation: Dholera Special Investment Region Strategically located, the Ahmedabad-Dholera industrial region lies within 100 km from the Dedicated Freight Corridor (DFC) in Central Gujarat

Connectivity:

National Highway 8 connects the Dholera Special Investment Region with Ahmedabad, Bhavnagar and Mumbai. Dholera itself has good connectivity with National Highway (NH) 8 (Anand) and 8A (Bagodra), augmenting Bagodra -Bhavnagar, Bagodra- Surendranagar- Radhanpur links

As a part of Golden Quadrilateral, the 500 km Mumbai- Ahmedabad- Vadodara Express way connects the region

In order to make the region more assessable, an airport and a port are proposed in this region.

The port site is proposed to be connected by road with Ahmedabad – Bhavnagar highway at a distance of about 11 kilometres. Almost 2,057 hectares of Government land was allocated for the development of port site

Rail connection is being planned for Dholera, while the nearest meter gauge connection is Bhavnagar (34 km) and the nearest broad gauge station is Tarapur (103 km)

Distance of DSIR from important cities

Important Cities Distance (in km)

Mumbai 516

Delhi 815

Surat 278

Jamnagar 313

Rajkot 225

Gandhinagar 128

Ahemdabad 105

Map --Road Connectivity to Dholera

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1 Map --Road Connectivity to DholeraMap---Rail Connectivity to Dholera

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SWOT ANALYSIS

STRENGTH

Dholera SIR : Ideally located, widely connected...

Total Area : 903 sq. kms: a green field location

Developable area: 547 sq. kms.

Economic activity area : 377 sq. kms

High Access Corridor: City Center, Industrial, Logistic, Knowledge & IT, Recreation & Sports, Entertainment

World-class infrastructure & connectivity: within & outside

Central spine express way & Metro Rail to link the SIR with mega cities

Airport & Sea Port in the vicinity

Proximity to mega cities: Ahmedabad, Bhavnagar, Vadodara

Benefit of sea coast, nature park, golf course

Premium civic amenities

Capable to cater to both International & Domestic Market

Close to Guajrat International Finance TechCity (GIFT)

Close to Petro-chemicals and Petroleum Inv. Region (PCPIR)

Logistic support of the Dedicated Freight Corridor (DMIC)

Benefits of the high impact Delhi Mumbai Industrial Corridor (DMIC)

Public investment in core infrastructure

PROJECT HIGHLIGHTS & OPPORTUNITY

A self governed economic region enjoying full support of the government and full potential for private sector participation

Logistic support of the Delhi-Mumbai Dedicated Freight Corridor linked with efficient rail and road network.

To be linked with Ahmedabad city with metro rail system

Proximity to sea port, Closeness to international airport

Premium civic amenities

Close to Gujarat International Finance City (GIFT)

Close to Petro-chemicals and Petroleum Inv. Region (PCPIR)

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Autonomy in operations

Flexibility in decisions

Single window clearance

Dispute Resolution mechanism

Opportunities in SIR

To build the industrial parks, townships, knowledge cities

In building its infrastructure: road, rail, hospital, water, sanitation, tourism, and hospitality

Set up the metro rail system & international airport

Potential for development as a multi-modal transportation hub due to lesser distance to all the northern Indian States.

Build world class transport service foreign markets

Current Status

Draft Development plan published on 05.01.2011

Location identified along with details of the area

The work on the central spine road already started

Notification issued for delineation of 879 Sq. Km of Area as DSIR

Government allocates 1700 Hect. land for adjoining Airport

Anchor Tenants already in place

Master plan prepared

Water logging, seismological & environment studies underway

The legal framework enacted: The SIR Act 2009

Project development corporation (GICC) formed

A high-rise is a tall building or structure

Buildings between 75 feet and 491 feet (23 m to 150 m) high are considered high-rises. Buildings taller than 492 feet (150 m) are classified as skyscrapers.

The materials used for the structural system of high-rise buildings are

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reinforced concrete and steel. Most American style skyscrapers have a steel frame, while residential tower blocks are usually constructed out of concrete.

High-rise structures have certain features. The structures are high & lead to higher vertical loads and higher lateral loads (mainly due to wind stress) in comparison with lower buildings.

LOADS ON THE HIGHRISE STRUCTURESVertical Loads Dead loads arise from the weigh to the individual construction elements and the finishing

loads. Live loads are dependent on use depending on the number of stories; live loads can be

reduced for load transfer and the dimensioning of vertical load-bearing elements.· However, the reduction of the total live load on a construction element may not exceed 40%.Horizontal Loads Calculation of lateral loads should be carefully scrutinized. It generally arises from unexpected deflections, wind and earthquake loadsUnexpected Deflections It arises from imprecision in the manufacture of construction elements and larger

components. Another cause is the uneven settling of the foundation at an in-homogeneous site. Any deflection produces additional lateral forces.Wind Loads High-rise buildings are susceptible to oscillation. It should not be viewed as statically

equivalent loads, but must be investigated under the aspect of sway behaviour. Wind tunnel experiments are used to see the influence of the building’s shape on the wind

load. The ability of wind loads to bring a building to sway must also be kept in mind. This oscillation

leads both to a perceptible lateral acceleration for occupants, and to a maximum lateral deflection.

Earthquake LoadsDefinition Seismology (from the Greek seismos= earthquake and logos= word) scientific study of earthquakes propagation of elastic waves through the Earth. studies of earthquake effects, such as tsunamis diverse seismic sources such as volcanic, tectonic, oceanic, atmospheric, and artificial

processes such as explosions.Earthquake Produce different types of seismic waves. It travel through rock, and provide an effective way to image both sources and structures

deep within the Earth.Seismic WavesThere are three basic types of seismic waves in solids: P-waves S-waves P-and/or S-waves. The two basic kinds of surface waves (Raleigh and Love).Pressure waves/Primary waves /P-waves, Travel at the greatest velocity within solids and are therefore the first waves to appear on a

seismogram. P-waves are fundamentally pressure disturbances that propagate through a material by

alternately compressing and expanding (dilating) the medium, where particle motion is parallel to the direction of wave propagation.

Shear waves/secondary waves/S-waves,

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Transverse waves that travel more slowly than P-waves and thus appear later than P-waves on a seismogram.

Particle motion is perpendicular to the direction of wave propagation. Shear waves do not exist in fluids such as air or water.

Type of High-Rise Structure

1. Braced Frame2. Rigid Frame Structure3. Infilled Frame Structure4. Flat Plate and Flat Slab Structure5. Shear wall structure6. Coupled wall structure7. Wall-frame structure8. Framed tube structure9. The trussed tube

10. Tube in tube or Hull core structure11. Bundled tube structure12. Core and Outriggers system13. Hybrid structureBraced Frame Braced frames are cantilevered vertical trusses resisting laterals loads primarily through the

axial stiffness of the frame members. The effectiveness of the system, as characterized by a high ratio of stiffness to material

quantity, is recognized for multi-storey building in the low to mid height range. Generally regarded as an exclusively steel system because the diagonal are inevitably

subjected to tension for or to the other directions of lateral loading. Able to produce a laterally very stiff structure for a minimum of additional material, makes it an

economical structural form for any height of buildings, up to the very tallest.Advantages:- Girders only participate minimally in the lateral bracing action-Floor framing design is

independent of its level in the structure. Can be repetitive up the height of the building with obvious economy in design and

fabrication.Disadvantages:-Obstruct the internal planning and the locations of the windows and doors; for this reason,

braced bent are usually incorporated internally along wall and partition lines, especially around elevator, stair, and service shaft.-Diagonal connections are expensive to fabricate and erect.

Rigid Frame StructureConsist of columns and girders joined by moment resistant connections. Lateral stiffness of a

rigid frame bent depends on the bending stiffness of the columns, girders, and connection in the plane of the bents. Ideally suited for reinforced concrete buildings because of the inherent rigidity of reinforced concrete joints. Also used for steel frame buildings, but moment-resistant connections in steel tend to be costly. While rigid frame of a typical scale that serve alone to resist lateral loading have an economic height limit of about 25 stories, smaller scale rigid

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frames in the form of perimeter tube, or typically rigid frames in combination with shear walls or braced bents, can be economic up top much greater heights.

Advantages:- May be place in or around the core, on the exterior, or throughout the interior of the building

with minimal constraint on the planning module. The frame may be architecturally exposed to express the grid like nature of the structure. The spacing of the columns in a moment resisting frame can match that required for gravity

framing.-Only suitable for building up to 20 –30 stories only; member proportions and materials cost become unreasonable for building higher than that.

Fig. WTC OSAKA JAPAN

In-filled Frame StructureMost usual form of construction for tall buildings up to 30 stories in height Column and girder

framing of reinforced concrete, or sometimes steel, is in-filled by panels of brickwork, block work, or cast-in-place concrete. Because of the in-filled serve also as external walls or internal partitions, the system is an economical way of stiffening and strengthening the structure. The complex interactive behavior of the infill in the frame, and the rather random quality of masonry, has made it difficult to predict with accuracy the stiffness and strength of an in-filled frame.

Fig. Infilled Frame.Flat-Plate and Flat Slab Structure Is the simplest and most logical of all structural forms in

that it consists of uniforms slabs, connected rigidly to supporting columns.

The system, which is essentially of reinforced concrete, is very economical in having a flat soffit requiring the most uncomplicated formwork and, because of the soffit can be used as the ceiling, in creating a minimum possible floor depth.

Lateral resistance depends on the flexural stiffness of the components and their connections, with the slab corresponding to the girder of the rigid frame.

Particularly appropriate for hotel and apartment construction where ceiling space is not required and where the slab may serve directly as the ceiling.

Economic for spans up to about 25 ft. (8m),above which drop panels can be added to create a flat-slab structure for span of up to 38 ft. (12m).

Suitable for building up to 25 stories height.Shear Wall StructureConcrete or masonry continuous vertical walls may serve both

architecturally partitions and structurally to carry gravity and lateral loading. Very high in plane stiffness and strength make them ideally suited for bracing tall building Act as vertical cantilevers in the form of separate planar walls, and as non-planar assemblies of connected walls around elevator, stair and service shaft. well suited to hotel and residential buildings where the floor-by floor repetitive planning allow the walls to be vertically continuous and where they serve simultaneously as excellent acoustic and

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Figure 3ACT TOWER, HIMASTU JAPAN

fire insulators between rooms and apartments. Minimum shrinkage restraint reinforcement where the wall stresses are low, which can be for a substantial portion of the wall.

Tensile reinforcement for areas where tension stresses occur in walls when wind uplifts stresses exceeds gravity stresses.

Compressive reinforcement with confinement ties where high compressive forces require the walls is designed as columns. Individual shear walls, say at the edge of a tall building, are design as blade walls or as columns resisting shear and bending as required.

High strength concrete has enable wall thickness to be minimized, hence maximizing rentable floor space.

Technology exists to pump and to place high-strength concrete at high elevation.

Fire rating for service and passenger elevator shafts is achieved by simply placing concrete of a determined thickness.

The need for complex bolted or side-welded steel connections is avoided. Well detail reinforce concrete will develop about twice as much damping as structural steel.

This advantage where acceleration serviceability is critical limits state, or for ultimate limits state design in earthquake-prone area.

Action to be considered:- Shear wall formed around elevator and service risers requires a concentration of opening at

ground level where stresses are critical. Torsional and flexural rigidity is affected significantly by the number and the size of opening

around the shear walls throughout the height of the building. Shear wall vertical movements will continue throughout the life of the building. Construction time is generally slower than for a steel frame building. The additional weight of the vertical concrete elements as compared to steel will induce a cost

penalty for the foundations. An increase in mass will cause a decrease in natural frequency and hence will most likely

produce an adverse effect of the acceleration response depending on the frequency range of the building. But shear wall systems are usually stiff and cause a compensating increase in natural frequency.

Problem associated with formwork systems: A significant time lag will occur between footing construction and wall construction, because

of the fabrication and erection on site of the moving formwork systems Time will be lost at the levels where wall are terminated or decrease in thickness, alignment of

the shear walls are within tolerance. Regular survey check must be undertaken to ensure that the vertical and twist alignment of

the shear walls are within tolerance. In general it is difficult to achieve a good finish from slip-form formwork systems, and hence

rendering or some other type of finishing may be necessary.

Shear wall StructureCoupled Wall Structure Consist of two or more shear walls in the same plane, or almost the same plane, connected at

the floor levels by beam or stiff slabs. The effect of the shear-resistant connecting members is to cause the sets of wall to behave in

their partly as a composite cantilever, bending about the common centroid axis of the walls.

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Suited for residential construction where lateral-load resistant cross walls, which separate the apartments, consist of in-plane coupled pairs, or trios, of shear walls between which there are corridor or window openings. Besides using concrete construction, it occasionally been constructed of heavy steel plate, in the style of massive vertical plate or box girders, as part of steel frame structure.

Coupled shear walled structureWall-Frame Structure The walls and frame interact horizontally, especially at the top, to produce stiffer and stronger

structure. The interacting wall-frame combination is appropriate for the building in the 40 –60 story range, well beyond that of rigid frames or shear walls alone.

Carefully tuned structure, the shear of the frame can be made approximately uniform over the height, allowing the floor framing to be repetitive. Although the wall-frame structure is usually perceived as a concrete structural form, with shear wall and concrete frames, a steel counterpart using braced frames and steel rigid frames offers similar benefits of horizontal interaction.

The braced frames behave with an overall flexural tendency to interact with the shear mode of the rigid frames.

Wall frame structure

Majestic building, Wellington, New Zealand.The lateral resistant of the framed-tube structures is provided

by very stiff moment-resistant frames that form a “tube” around the perimeter of the building. The basic inefficiency of the frame system for reinforced concrete buildings of more than 15 stories resulted in member proportions of prohibitive size and structural material cost premium, and thus such system were economically inviable. The frames consist of 6-12 ft. (2-4m) between centers, joined by deep spandrel girders. Gravity loading is shared between the tube and interior column or walls. When lateral loading acts, the perimeter frame aligned in the direction of loading acts as the “webs” of the massive tube of the cantilever, and those normal to the direction of the loading act as the “flanges”. The tube form was developed originally for building of rectangular plan, and probably its most efficient use in that shape.

Suitable for reinforced concrete and steel construction and has been used for building ranging from 40 to more than 100 stories. Aesthetically, the tube externally evident form is regarded with mixed enthusiasm; some praise the logic of clearly expressed structure while other criticizes the grid like façade as small-windowed and uninterestingly repetitious. Depending on the height and dimensions of the building, exterior columns spacing should be in order of 1.5 m to 4.5 m on center maximum. Spandrel beam depths for normal office or residential occupancy application are typically 600 mm to 1200 mm. Frame tube in structural steel requires welding of the beam-column joint to develop rigidity and continuity. The formation of fabricated tree elements, where all welding is performed in the shop in a horizontal position, has made the steel frame tube system more practical and efficient. The 110 story World Trade Center twin towers, New York are examples whereby the structuralism notion of a punched wall tube with

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extremely close exterior columns is architecturally exploited to express visually the inherent verticality of the high rise building.

The Trussed tube: The trussed tube system represents a classic solution for a tube uniquely suited to the

qualities and character of structural steel. Interconnect all exterior columns to form a rigid box, which can resist lateral shears by axial in

its members rather than through flexure. Introducing a minimum number of diagonals on each façade and making the diagonal

intersect at the same point at the corner column. The system is tubular in

that the fascia diagonals not only form a truss in the plane, but also interact with the trusses on the perpendicular faces to affect the tubular behavior. This creates the x form between corner columns on each façade.

Relatively broad column spacing can resulted large clear spaces for windows, a particular characteristic of steel buildings.

The façade digitalization serves to equalize the gravity loads of the exterior columns that give a significant impact on the exterior architecture.

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Tube-in-Tube or Hull Core Structure This variation of the framed tube consists of an outer frame

tube, the “Hull,” together with an internal elevator and service core.

The Hull and core act jointly in resisting both gravity and lateral loading.

The outer framed tube and the inner core interact horizontally as the shear and flexural components of a wall-frame structure, with the benefit of increased lateral stiffness.

The structural tube usually adopts a highly dominant role because of its much greater structural depth.

Bundled-Tube structures The concept allows for wider column spacing in the tubular

walls than would be possible with only the exterior frame tube form.

The spacing which make it possible to place interior frame lines without seriously compromising interior space planning.

The ability to modulate the cells vertically can create a powerful vocabulary for a variety of dynamic shapes therefore offers great latitude in architectural planning of a tall building.

Core and Outrigger Systems Outrigger serve to reduce the overturning moment in the

core that would otherwise act as a pure cantilever, and to transfer the reduced moment to columns outside the core by the way of tension-compression coupled, which take advantage of the increase moment arm between these columns.

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It also serves to reduce the critical connection where the mast is stepped to the keel beam.

In high-rise building this same benefit is realized by a reduction of the base core over-turning moments and the associated reduction in the potential core uplift forces.

In the foundations system, this core and outrigger system can lead to the need for the following:

The addition of expensive and labor-intensive rock anchors to an otherwise “simple” foundation alternative such as spread footing.

Greatly enlarged mat dimensions and depth solely to resist overturning forces.

Time-consuming and costly rock sockets for caisson systems along with the need to develop reinforcement throughout the complete caisson depth.

Expensive and intensive field work connection at the interface between core and the foundation. This connection can become particularly troublesome when one considers the difference in construction tolerances between foundations and core structure.

The elimination from consideration of foundation systems which might have been considerably less expensive, such as pile, solely for their inability to resist significant uplift.

Advantages: The outrigger systems may be formed in any combination of steel, concrete, or composite

construction. Core overturning moments and their associated induced deformation can be reduced through

the “reverse” moment applied to the core at each outrigger intersection. This moment is created by the force couple at the exterior columns to which the outrigger connect. It can potentially increase the effective depth of the structural system from the core only to almost the complete building.

Significant reduction and possibly the complete elimination of uplift and net tension forces throughout the column and the foundation systems.

The exterior column spacing is not driven by structural considerations and can easily mesh with aesthetic and functional considerations.

Exterior framing can consist of “simple” beam and column framing without the need for rigid-frame-type connections, resulting in economies.

For rectangular buildings, outriggers can engage the middle columns on the long faces of the building under the application of wind loads in the more critical direction. In core-alone and tubular systems, these columns which carry significant gravity load are either not incorporated or under-utilized. In some cases, outrigger systems can efficiently incorporate almost every gravity column into lateral load resisting system, leading to significant economies.

DisadvantagesThe most significant drawback with use of outrigger systems is their potential interference with

occupiable and rentable space. This obstacle can be minimized or in some cases eliminate by incorporation of any of the following approaches:

Locating outrigger in mechanical and interstitial levels Locating outriggers in the natural sloping lines of the building profile Incorporating multilevel single diagonal outriggers to minimize the member interference on

any single level. Skewing and offsetting outriggers in order to mesh with the functional layout of the floor

space. Another potential drawback is the impact the outrigger installation can have on the erection

process. As a typical building erection proceeds, the repetitive nature of the structural framing

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and the reduction in member sizes generally result in a learning curve which can speed the process along.

The incorporation of a outrigger at intermediate or upper levels can, if not approached properly, have a negative impact on the erection process. Several steps can be taken to minimize this possibility Provide clear and concise erection guidelines in the contract documents so that the erector can anticipate the constraint and limitation that the installation will impose. If possible, avoid outriggers locations or design constraints that will require “backtracking” in the construction process to install or connect the outrigger. The incorporation of intermediate outriggers in concrete construction or large variation in dead-load column stresses between the core and the exterior can in some cases result in the need to “backtrack”. Such a need can be minimized if issues such as creep and differential shortening are carefully studied during the design process to minimize their impact. Avoid adding additional outrigger levels for borderline force or deflection control.

Hybrid StructureCombination of two or even

more of basic structural forms either by direct combination or by adopting different forms in different parts of the structure. This systems provide in-plane stiffness, its lack of Torsional stiffness requires that additional measures be taken, which resulted in one bay vertical exterior bracing and a number of level of perimeter Vierendeel “bandages” –perhaps one of the best examples of the art of structural engineering. Hybrid structures are likely to be the rule rather than the exception for future very tall buildings, whether to create acceptable dynamic characteristics or to accommodate the complex shapes demanded by modern architecture. High-strength concrete, consist of stiffness and damping capabilities of large concrete elements are combined with the lightness and constructability of steel frame exhibits significantly lower creep and shrinkage and is therefore more readily accommodated in a hybrid frame.

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CHAPTER -2 LITERATURE SURVEY

2.0DATA COLLECTION2.1PLANNING AND DESIGNING OF HIGH RISE BUILDINGS 2.1.1 BASIC PLANNING CONSIDERATIONSBask planning considerations for high rise building design include the following parameters:• Planning module• Span• Ceiling height• Floor-to-lloor height• Depth of structural floor system• Elevator system• Core planning

Parking

Planning module, namely the space one needs for living, changes according to the culture and the economic class.

Span, described as the distance from a fixed interior clement such as building core to exterior window wall, is another important criterion for good interior planning. These depths change depending on the function of the space, and acceptable span is determined by office layouts, hotel room standards, and residential code requirements for outside light and air. Usually, the depth of the span should be between 12 and 18 m for office functions, except where very large single tenant groups are to be accommodated. Lease span for hotels and residential units range from 9 to 12M.

Ceiling height (Fig: 2.1) is also an important factor in building planning. Commercial functions require a variety of ceiling heights ranging between 2.7 and 3.7 m. While office functions necessitate ceiling heights of approximately 2.5 to 3.0 m, residential and hotel functions require ceiling heights of 2.5 to 3.0 m.Fig 2.1 Ceiling height and floor to- floor height. Floor-to-floor height (Fig: 2.1), which is a function of the necessary ceiling height, the depth of the structural lloor system, and the depth of the space required for mechanical distribution, determines the overall height of the building, and affects the overall cost. A small increase or decrease in floor-to-floor height, when multiplied by the number of floors and the area of the perimeter enclosure by the building, can have a great effect on many systems such as the exterior, structural, mechanical system, and the overall cost.

Depth of structural floor system plays an important role for planning considerations in high rise buildings, and varies broadly depending on the floor load requirements, size of the structural bay. and type of floor framing system.

Elevator system is another major component for good interior planning. In the design of an elevator system, wailing interval, elevator size and speed interpretation of program criteria, areas to be served, the population density of the building, and the handling capacity of the system at peak periods, must be considered. This becomes even more complicated for mixed-use projects.

For preliminary planning, one elevator per 1000 m2 of gross area is a rule of thumb for estimating the number of elevators needed. Besides this, the net usable area varies from one elevator zone to another and from floor to floor, and should average from 80 to 85% over the entire building. The sky-lobby concept is an important and innovative approach in elevator system design. This concept uses high-speed express shuttle cars to transport passengers from the ground level to a

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lobby higher up in the building for transfer to local elevator zones so that the area used for elevator shafts and lobbies on the lower floors of the building is reduced.

Core planning is another significant issue for planning considerations. A typical floor in a high rise building contains a perimeter zone, an interior zone, and a core zone. While perimeter zone is described as an approximately 4.5 m or 5 m deep area from the window wall with access through the interior zone, interior zone is defined as the area between the perimeter and the public corridor. On the other hand, core zone consists of those areas between elevator banks which become rentable on floors at which elevators do not stop. Central core, which is generally used in the buildings with a rectangular plan, and split core. which is generally used in the building with a relatively square plan, is the most typical core arrangements. Cores accommodate elevator shafts, mechanical shafts, stairs, and elevator lobbies. Core elements that pass through or serve every floor should be located, so that they can rise continuously, and thus avoid expensive and space-consuming transfers.

Parking is another planning requirement, which varies according to different functions such as business, residential, and like. When parking facility provided within the footprint of the building, it has a great impact on the plan and the structure. If it is inevitable, the structural bay should be well arranged to obtain efficient space use for parking and functional areas, and the core elements should be effectively located to minimize interference with car parking and circulation. Mechanical ventilation is one other important concern for the user of parking facility, and pedestrian

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2.1.2 BASIC DESIGN CONSIDERATIONS

The basic design considerations for a high rise building include the following parameters:• the cultural, political, and social aspects of the city where the building will be located• a strong relationship with the city• the master plan and an appropriate site selection• sustainability• safety and security issues• learning about the possibilities and limitations of technology

When a high rise building is designed, the design team should also be aware of the codes, regulations, zoning requirements, and life safety issues.

The master plan is one of the significant design considerations for high rise buildings, in which we 11-performed site analysis include, automobile, traffic and pedestrian impact, accessibility, minimal blockage of view, and minimizing the building shadows to neighboring buildings. Besides this, an appropriate site selection also includes the consideration of reuse or rehabilitation of existing buildings, and physical security. The location of high rise buildings within an urban area affects the amount of day lighting, and may even create wind tunnels.

Sustainability is also a key element in high rise building design. This concept is based on the following objectives: optimization of site potential, minimization of energy consumption, protection and conservation of water, use of environmental- friendly products, enhancement of indoor environmental quality, and optimization of operational and maintenance practices. Day lighting, natural shading, energy efficient and photovoltaic facades, wind power systems, and the sky garden concept are also the main parameters for a more sustainable high rise building design.Designing a safe and secure high rise building has always been a primary goal Tor owners, architects, engineers, and project managers. There is an increased concern on these issues for high rise building design especially after the disastrous 9/11 incident. Natural disasters, acts of terrorism, indoor air quality, hazardous materials, and fire are very significant and immediate safety issues to be considered in the design.

Learning about the possibilities and limitations of technology is critical for the success of the project. New technology and new building materials are being introduced at a fast rate; it is important to track these changes. The different demands of the ever changing nature of business and lifestyle also force us to be aware of the technological changes.2.2 HIGH RISE DESIGN FOR EARTHQUAKE ZONES 2.2.1 NATURE OF EARTHQUAKEThe earth's outer layer is composed of plates ranging in thickness from 32 to 241 km. The plates are in constant motion, riding on the molten mantle below, and normally traveling at the rate of a millimeter a week, which is equivalent to the growth rate of a fingernail. Hence, this motion causes continental drift and the formation of mountains, volcanoes, and earthquakes

The Richter scale is a logarithmic scale for determining the energy dissipated in an earthquake. This means that an earthquake measuring 7 on the Richter scale dissipates 32 times the energy of a size-6 quake, while one measuring 8 dissipates roughly 1.000 times as much energy. The energy dissipated by these earthquakes is expressed in horizontal and vertical acceleration forces acting on the skyscrapers. The immense forces transmitted from underground must be absorbed by the supporting structures of the buildings. These dynamic loads are replaced by structural equivalent loads in horizontal and vertical direction when a structural analysis of the building is performed.

2.2.2 ACTION OF SEISMIC LOADS ON THE BUILDINGThe horizontal and vertical acceleration of the subsoil due to an earthquake causes the building to vibrate. In simplified form, these loads can be represented by horizontal and vertical equivalent loads acting on the mass centre of gravity of the building. The magnitude of these equivalent loads depends directly on the mass of the building. This leads to the conclusion that as the height of the building increases, the mass centre of gravity normally wanders upwards and the llexural effect on the building is intensified by the longer lever arm. The potential earthquake damage suffered by high-rise buildings varies. The damage depends more on the rate of motion and magnitude of the displacement than on the acceleration.

2.2.3 ROLE OF SUBSOIL

Natural rock is the best subsoil from the point of view of its earthquake properties. Sandy soils saturated with water and artificially backfilled land are considered to be particularly critical. The widely-feared liquefaction effects (plasticization of the soil) can occur if an earthquake coincides with high groundwater levels. The building may subsequently remain at a slant or both the building and the surrounding terrain may subside.

2.2.4 FOUNDATIONS DESIGN FOR EARTHQUAKE

Deep foundations generally display better seismic resistance than shallow foundations. Floating foundations can prove advantageous on soft ground, since they may be better able to attenuate resonance action. The risk of subsidence is considerably greater with floating foundations than with deep foundations. "Base isolation" is an anti-seismic construction technique that uses the principle of attenuation to reduce vibrations. The building is isolated from the solid subsoil by damping elements arranged on a foundation ring or foundation plate. The building was retroactively more or less mounted on ball bearings which arc intended to gently damp down the impact of a future earthquake. As in the case of wind loads, earthquakes can also give rise to resonant vibration.2.2.5 HEIGHT OF THE BUILDING

High rise buildings are more susceptible to damage from strong remote earthquakes than from weak earthquakes close at hand. They normally have a lower resonant frequency and a lower attenuation than low buildings. Short-wave oscillation components in earthquakes are rapidly damped, while the long-wave components (frequency f<l Hz) can still make themselves felt at a distance of several hundred kilometers, particularly in the form of surface waves.

2.2.6 SYMMETRY OF THE HIGH-RISE BUILDING

Symmetric layouts, rigidity and mass distribution lead to a considerably better seismic response than asymmetric layouts, rigidity and mass distribution. This is because asymmetric buildings are subjected to stronger torsion (twisting) around the vertical axis by horizontal seismic loads.

2.2.7 SHAPE OF THE HIGH-RISE BUILDING

When parts of different height are permanently connected to one another as, for example, is often found in high-rise buildings with atriums, then the various structures in the building can be subjected to considerable torsional stresses by the seismic loads. Buildings of different heights can also be subjected to a whole series of effects in an earthquake, higher buildings were literally jammed in between lower buildings, thus extensively damaging the floors at the clamping point. In some cases, the buildings simply buckled over at the edge of the lower adjacent buildings.

Resonance effects can also cause buildings to oscillate so strongly that they hammer against one another. Another effect observed in high-rise buildings is the soft-storey effect: due to lobbies, atriums or glazed shopping passages, some floors - usually near the ground floor - are distinctly "softer" than those above them. These "soft" floors then collapse in an earthquake.

2.3 LATERAL LOADS ON HIGH RISE BUILDINGSFrom the structural design point of view, due to its height, a high rise building could be described, as one that is more affected by lateral loads treated by wind or earthquake actions compared to other building types. Thus, loads acting on high rise buildings are different from those on low rise buildings in terms of accumulation into much larger structural forces, and the increased importance of wind loading. Wind loads on a high rise building act not only over a very large surface, but also with greater amount at the greater heights, and with a larger moment arm than on a low- rise building.

Even though the wind loads on a low-rise building generally have a minor affect on the design and structural configuration, they can play a vital cole for the selection of the structural system in a high rise building. Depending upon the mass and shape of the building, and the region, although, the wind load is very important in the design of high rise buildings, in seismic regions, inertia! loads from the shaking of the ground also play an important role. Furthermore, in contrast to vertical loads which can be estimated roughly from previous field observations, lateral loads, namely the wind and earthquake loads, on buildings are fairly unpredictable, and cannot be assessed accurately.

2.3.1 NATURE OF WIND

Wind, which is created by temperature differences, could be described as an air motion, generally applied to the natural horizontal motion of the atmosphere. The vertical motion, on the other hand, is termed as a current. Air close to the surface of the earth moves three dimensionally, in which horizontal motion is much greater than the vertical motion. While the vertical air motion is significant particularly in meteorology, the horizontal motion is important in engineering. The surface boundary layer concerning the horizontal motion of wind extends upward to a certain height above which the horizontal airflow is no longer affected by the ground effect. Most of the human activity is performed in this boundary layer, and hence how the wind effects are felt within this zone is of great concern in engineering.Wind is a very complex phenomenon owing to the many flow situations resulting from the interaction of wind and structure. In wind engineering, on the other hand, simplifications are made to find meaningful predictions of wind behavior by distinguishing the following features:• variation of wind speed with height• turbulent and dynamic nature of wind• vortex-shedding phenomenon• cladding pressures

2.3.2 WIND EFFECTS ON HIGH RISE BUILDINGSThe wind is the most powerful and unpredictable force affecting high rise buildings. High rise building can be defined as a mast anchored in the ground, bending and swaying in the wind, This movement, known as wind drift, should be kept within acceptable limits. Moreover, for a well-designed high rise building, the wind drift should not surpass the height of the building divided by 500. Wind loads on buildings increase considerably with the increase in building heights. Furthermore, the speed of wind increases with height, and the wind pressures increase as the square of the wind speed. Thus, wind effects on a high rise building are compounded as its height increases. Besides this, with innovations in architectural treatment, increase in the strengths of materials, and advances in methods of analysis, high rise building have become more efficient and lighter, and so, more vulnerable to deflection, and even to swaying under wind loading.

The swaying at the top of a high rise building induced by wind may not be seen by a passerby,

but its effect may be a concern for those occupying the top floors. Unlike dead loads and live loads, wind loads change rapidly and even abruptly, creating effects much larger than when the same loads were applied gradually, and that they limit building accelerations below human perception.

2.3.3 VARIATION OF WIND SPEED WITH HEIGHT

Ail important characteristic of wind is the variation of its speed with height (Fig: 2.2). The wind speed increase follows a curved line varying from zero at the ground surface to a maximum at some distance above the ground. The height at which the speed stops to increase is called the gradient height, and the corresponding speed, the gradient wind speed. This important characteristic of wind is a well understood phenomenon that higher design pressures are specified at higher elevations in most building codes.

Additionally, at heights of approximately 366 m from the ground, surface friction has an almost negligible effect on the wind speed; as such the wind movement is only depend on the prevailing seasonal and local wind effects. The height through which the wind speed is affected by the topography is called atmospheric boundary layer. The wind speed profile within this layer is in the domain of turbulent flow and could be mathematically calculated.

wind

2.3.4 TURBULENT AND DYNAMIC NATURE OF WIND

WinJ transfers some amount of its energy to the object that it hit on its path. The measure of the amount or energy transferred is called the gust response factor. Terrain roughness and variety of the height above ground, affect wind turbulence (also known as gustiness).Wind loads related with gustiness or turbulence, change rapidly and even abruptly unlike the mean flow of wind with static characteristic. Furthermore, the motion of wind is turbulent. Turbulence can be described as, any movement of air at speeds greater than 0.9 to 1,3 m/s, resulting in random movement of air particles in all directions. The scale and intensity of turbulence can be related to the size and rotating speed of eddies (a circular movement of wind) that create the turbulence. Additionally, the flow of a large mass of air has a larger overall turbulence than that of a small mass of air. Consequently, from the structural engineer's point of view, the wind speed can be considered to include two components; a mean speed component increasing with height and a turbulent speed fluctuation.

2.3.5 VORTEX-SHEDDING PHENOMENON

Along wind and across wind are two important terms used to explain the vortex- shedding phenomenon. Along wind or simply wind is the term used to refer to drag forces. The across wind response is a motion, which happens on a plane perpendicular to the direction of wind. When a building is subjected to a wind flow, the originally parallel wind stream lines are displaced on both transverse sides of the building (Fig 2.3). and the forces produced on these sides are called vortices.

Fig 2.3 Simplified wind flowAt low wind speeds, the vortices arc shed symmetrically (at the same instant) on either transverse side of the building (Fig 2.4a), and so building does not vibrate in the across wind direction.

Fig 2.4 Vortices in different wind speed conditions: (a) vortices in low speed of wind (there is no vibration in the across wind direction); (b) vortices in high speed of wind - vortex-shedding phenomenon (there is vibration in the across wind direction)

(a)

Wind

(b)

On the other hand, at higher wind speeds, the vortices are shed alternately first from one and then from the other side. When this occurs, there is an impulse both in the along wind and across wind directions. The across wind impulses are, however, applied alternatively to the left and then to the right. This kind of shedding which causes structural vibrations in the flow and the across wind direction is called vortex- sheddingi a phenomenon well known in fluid mechanics. This phenomenon of alternate shedding of vortices for a rectangular high rise building is shown schematically in Fig: 2,4b,

2.3.6 CLADDING PRESSURES

The cladding design for lateral loads is a very significant subject for architects and engineers. Even though the broken glass resulting from the exterior cladding failure may be a less important consideration than the structural collapse during an earthquake, the cost of replacement and risks for pedestrians require careful concentration in its design. Wind forces play a major role in glass breakage, also affected by solar radiation. muJJion and sealant details, tempering of the glass, double or single glazing of glass, and fatigue. Breaking of large panels of glass in high rise buildings can badly damage the neighboring properties and injure the pedestrians.

2.4 STRUCTURAL SYSTEMS FOR HIGH RISE BUILDINGS: LATERAL LOAD RESISTING SYSTEMSThe key idea in conceptualizing the structural system for a slender high rise building is to think of it as a beam cantilevering from the earth. As a general rule, when other things being equal, the high rise building more necessary is to identify the proper structural system for resisting lateral loads, in which the rigidity and stability requirements arc often the dominant factors in the design. Moreover, the selection of the structural system of a high rise building involves the following factors:• economic criteria related to the budget of the project;• function of the building;• internal planning;• material and method of construction;• external architectural treatment;• planned location and routing of the service systems;• height and proportions of the building.

Consequently, the effect of lateral loads must be considered from the very beginning of the design process, and the structural systems need to be developed around concepts associated entirely with resistance to these load Basically, there arc three main types of buildings: steel buildings, reinforced concrete buildings, and composite buildings.

2.4.1 STEEL, REINFORCED CONCRETE AND COMPOSITE HIGH RISE BUILDINGS

Even though the application of steel in structures can be traced back to Bcssemers steelmaking process (1856). its application to high rise structures received its stimulus from the 300 m high Eiffel Tower (1889). Furthermore, the role of steel members which used to carry only gravity loads in the early structures, has been entirely upgraded to include wind and earthquake resistance in systems ranging from the modest portal frame to innovative systems involving outrigger systems, interior and exterior braced frames, and like. Today, structural steel could be utilized in a variety of structures from low-rise parking areas to 100-story high skyscrapers.

Most of the high rise buildings in the world have steel struetural system, due to its high strength-to-weight ratio, case of assembly and economy in transport to the site, availability of various strength levels, and wider selection of sections. Innovative framing systems and modern design methods, improved fire protection, corrosion resistance, fabrieation, and erection techniques combined with the advanced analytical techniques made possible by computers, have also permitted the use of steel in just any rational struetural system for high rise buildings.

Although concrete as a structural material has been known since early times, the practical use of reinforced concrete was only introduced in 1867. The invention of reinforced concrete increased the significance and use of concrete in the construction industry to a great extent. Partieularly, because of its moldability characteristics, and natural fireproof property, architects and engineers utilize the reinforced concrete to shape the building, and its elements in different and elegant forms, Besides this, when compared to steel, reinforced concrete high rise buildings have better damping ratios eontributing to minimize motion perception and heavier concrete structures offer improved stability against wind loads. Moreover, high strength concrete and lightweight structural concrete allow using smaller member sizes and less steel reinforcement. All high rise buildings can be considered as composite buildings since it is impossible to eonstruet a funetional building by using only steel or concrete.

In this study, buildings having reinforced concrete beams, columns, and shear walls arc accepted as reinforced concrete (or concrete) buildings, and in the same way, buildings having steel beams, columns and bracings are accepted as steel buildings. Namely, the frame and bracing or shear walls - but not the floor slabs - are the determining parameters for the building type. A concrete column became more economical than a pure steel column thanks to the introduction of high and ultra- high-strcngth concrete with compressive strength up to 18 IMPa in I960, Besides the economic feature, moldability. high stiffness and insulating, and fire-resisting quality of concrete, have all contributed to realize its structural combination with steel which has merits of high strength-to-weight ratio especially for seismie zones, fast construction, long span capacity, ease of assembly and field work.Both steel and concrete constructions have advantages and drawbacks. Moreover, without composite construction, many of our contemporary high rise buildings may never have been constructed in their present form today. On the other hand, here, the term composite system means any and llII combinations of steel and reinforced concrete elements and is considered synonymous with other definitions such as mixed systems, hybrid systems, etc. The classification of structural systems of high rise buildings are:

• F rame (rigidframe) systems;• Braced frame and shear walled frame systems;• Outrigger - belt truss systems;• Framed tube systems;• Braced (exterior braced) systems;• Bundled tube systems.

2.5 INSTALLATION OF SERVICE SYSTEMS

The installation for air-conditioning, ventilation, lighting and fire alarms are usually located between the load-bearing ceiling and a suspended false ceiling into which the lamps arc normally integrated. Small-scale electrical installations are contained in trucking in the screcd flooring. Cables can then be routed as desired in the space below the floor; the equipment is connected to sockets in so-called floor tanks. False floors are to be found almost everywhere in modern houses, since cables can be rerouted without difficulty, as is increasingly required on account of the rapid pace of change in office and communications technology. Moreover, the space below

the floor can also be used for ventilation and air-conditioning installations.

Particular attention must be paid to the question of fire protection in such false floor constructions. Connection of the flexible partition walls to both the suspended ceiling and the elevated false floor can pose problems. From the point of view of soundproofing and thermal insulation, it would be better to install high rise the partition walls between the load-bearing floors.

However, since the suspended ceilings and false floors normally extend over the entire area and are not confined to any single room on account of the technical installations, the partition walls must also be fitted between the suspended ceiling and false floor. This consequently makes it necessary to use soundproofing and thermally insulating floor coverings, as well as ceiling materials. Facade elements into which technical components have already been incorporated by the manufacturer are conveniently linked to the remaining network by means of screw-in and plug-in connections.

However, it is becoming increasingly rare for such technical service connections to be installed in the external walls, as they do not permit as flexible use of the room as floor tanks. Due to the relati vely small area available per floor, fire resistant elements (fire walls) are usually only to be found in the core areas incorporating the elevators, stairwells, service and installation shafts, sanitary and ancillary rooms. A vertical breakdown into fire compartments is mostly obtained with the aid of fire-resistant floor

2.5.1 ENERGY AND WATER SUPPLY

Unlike the case with normal multi-storey buildings, the technical service components in high rise buildings must meet special requirements if only on account of the height, since the required supply of energy, water and air and the effluent volume are incomparably larger. These utilities must also be transported to the very last floor in sufficient quantities, under adequate pressure and at sometimes to tally different temperatures. The planning effort required on the part of the service engineers responsible for the supply and disposal services in high-rise buildings is therefore very much greater than in the case of smaller and medium sized projects. The pressure load on the individual components is reduced through subdivision into several pressure stages with technical service centres in the basement or on the ground floor, on intermediate floors and on the roof.

Fig 2.5 Ventilation and Air-conditioning system

2.5.2 VENTILATION AND AIR-CONDITIONING

The systems should be designed in such a way as to ensure flexible division of the areas (large rooms, individual rooms) so that their use can subsequently be changed without extensive conversions. A variety of ventilation and air-conditioning systems can be installed, depending on the purpose for which the building is used. The high- rise headquarters of the Deutsche Bank in Frankfurt am Main, for instance, is supplied by a two-channel high-pressurea system in

which the air is injected from above and discharged throughcorresponding exhaust air windows. A second, independent two-channel high-pressure system additionally blows air into the rooms from the false floors.

In principle, all air- conditioning and ventilation systems must meet the same basic requirements:

2.5.3 SANITATION

Pressure stages are also required for the sanitation, thus permitting the use of smaller pumps. Sanitary dispensing points must additionally be isolated from the building as such for soundproofing reasons. The internal heat loads (e.g. hot exhaust air, exhaust heat from refrigeration systems) accumulated in high-rise buildings arc commonly used to heat water with the aid of heat pumps or heat recovery systems. Studies shown that the height does not have any effect on the flow rate and rate of fall, since fiscal matter and effluent do not simply drop to the ground under the force of gravity, but more or less wind their way downwards along the pipe walls.

2.5.4 CONTROL SYSTEMS

Today's complex, ultra-modern control systems are primarily based on intelligent digital controllers. This technology permits a direct link, between DDC (direct digital control) substations and the centralized instrumentation and control whieh also takes over energy management functions, such as:

• Optimization of the overnight and weekend temperature reduction.* Linking the heating of service water with re-cooling of the refrigeration system, operation of the

external blinds.

j i J u ".«mj ii <« i ■Proctor Pwditor BttJc Pralalor Prwfator Predator Predator LONMifLHea! Pump YAV Controller with Fart Coil Unit Vent Four-Loop Semen1 Third PartyPfojrjnviatte Cor#oiif Controller Actuator ConlroUar Ccxilrollw Controiictf VFO Draco Conaroter

Fig 2.6 Control system

1 The air in the room must be continuously renewed (at three to six fold exchange of air is normally required per hour).

• The outside air flow must be guaranteed with a minimum fresh air flow of 30 to 60 mj/h per person.

• The risk of drafts must be minimized and any nuisance due to the transmission of sound eliminated.

■ It must be possible to shut off individual plant segments when the corresponding parts of the building arc not in use.

LQnTAlk Mahtwk

•CH-

2.6 FIRE FIGHTING

Fire is one of the greatest risks for every building and particularly for high-rise buildings. Due to the spectacular photographs and film sequences shown in the media, major fires have always made - and will continue to make - headline news not only during the construction phase, but above all during the occupancy phase.

2.6.1. FIRE FIGHTER ACCESSIBILITYIt is important for emergency personnel (e.g. firefighters, paramedics, police) to be able to access a building quickly in the event of an emergency. In addition, these personnel cannot be expected to scale all doors through stairwells. This need gets back to the elevator systems. The tower has service elevators that run higher than local passenger elevators. In fact, one of these service elevators runs over the tower. These are very fast, and are configured to override the local elevators to allow for the quickest and easiest transfers. The elevators themselves are fire/smoke resistant. With these, it makes accessing the building a relatively painless process.

2.6.2 OCCUPANT EVACUATIONOccupant evacuation is the concern of any building; however, it poses a special challenge given the height of the high rise buildings. With the tremendous climb, occupants will need information on the situation, mechanical assistance to speed the process, and stairwells and safe zones in the event of mechanical failures. It is important to note that most crises the building will experience will not require full building evacuation. However, when lives are at stake, it is still important to be sure that it is possible.

2.6.3. AREAS OF REFUGE

The tower design includes strategically placed areas of refuge which allow for better controlled evacuation. Represented in Fig: 2.7, the typical area of refuge will have fire rated exit stairs closed off by doors to counter the spread of smoke. Building employees will be trained to direct and instruct evacuees. Also, the areas of refuge are designed to connect to various stairwells.

This means that occupants can be directed down the safest path, and will almost never be trapped. As usual, the areas of refuge arc encased in fire resistant concrete, are well ventilated, and can be lit by emergency lights.

Fig: 2.7 Typical design for area of Refuge

2.6.4 FIRE EXTINGUISHERS

Hand-operated fire extinguishers must be installed at clearly marked and generally accessible points in high-rise buildings in order to fight incipient fires. These extinguishers are intended for use by the building's residents. However, teams should be present on every floor made up of the people who work and live there; they must then be instructed on what to do if a fine breaks out and also be familiarized with the use of these hand-operated fire extinguishers.

2.6.5 FIRE-FIGHTING WATER

The cases outlined above have shown how important it is to have an effective supply of fire fighting water when combating a fire in a high-rise building. So that the firemen can start to fight the fire as soon as they arrive on the scene, wet risers must be installed in every stairwell or in their vicinity and a wall hydrant with hose line connected to these risers on every floor. The hoses must be sufficiently long to direct fire-fighting water to every point on that floor.

Ail adequately dimensioned water line and adequate water pressure must be ensured when planning and designing the building. In very high buildings, booster systems must be installed in the wet risers to increase the water pressure. Whether the water for fire-fighting can be taken from the public mains or from separate water reservoirs or tanks must be decided in each individual instance in accordance with local conditions and regulations. For greater safety, it may be useful to install not only wet risers, but also dry risers into which the fire brigade can feed water at the required pressure from the ground floor.

2.6.6 SPRINKLERS

An automatic sprinkler system is the most effective protective measure for fighting and controlling a fire in a high-rise building. Care must be taken to ensure that the complete building is protected by such sprinklers. In the cases outlined above, there were either no sprinklers at all or no activated sprinklers on the burning floors. Based on past experience, the installation of sprinkler systems is in many countries prescribed by law for high-rise buildings from a certain height onwards — as from 60 m in Germany, for example. In some cases, the statutory regulations even stipulate that sprinklers have to be installed retroactively in high-rise buildings erected before the regulations came into force.

Fig: 2.8 Automatic Sprinkler System

Automatic sprinkler systems throughout the building arc important since they must fight a fire as early as possible and must either extinguish the fire directly or keep it under control until the fire brigade arrives to finish off the job. However, a sprinkler system will normally be unable to control a fire in full flame, for instance if it leaps from a lloor with no sprinklers to one with sprinklers. Sprinkler systems are simply not dimensioned to cope with such developments.

Sprinkler systems must meet the following requirements:• They must rapidly control a fire in the fire compartment in which it breaks out;

• They must limit the emission and spread of flames, hot fumes and smoke, they must trigger an alarm in the building, preferably also indicating to the central control panel where the seat of the fire is located, the alert must be forwarded to the fire brigade or other auxiliary forces.

• The ability of the system to indicate to the central control panel where the seat of the fire is located presupposes that a separate sprinkler system with an alarm valve is assigned to each floor and to each fire compartment. As already mentioned in connection with fire-detection systems, the installation of an automatic fire-detection system in addition to the sprinkler system is advisable so that fires can be discovered and signaled more quickly. Sprinkler systems must be installed in accordance with the applicable directives or standards, the best known of which include NFPA. CEA, FOC and VdS. All the components used for installation must comply with the relevant standards.

The various directives and standards permit a variety of solutions with regard to the water supply:Water supply from the public mains - possibly via an intermediate tank on the ground - via booster pumps on the ground to supply several groups of floors with different pressure levels intermediate tanks on various upper floors, under either normal pressure or excess pressure, to supply the sprinkler groups above or below deep tanks and pressurized tanks on the roof, as well as intermediate tanks in the middle of the building, to supply the sprinklers below with static or high pressure Tanks on upper floors can be replenished via low-capacity pumps.

Depending on the type of supply selected, it may be necessary to install rise pressure- reducing valves on the individual floors. For a sprinkler system to operate smoothly, it must not only be correctly installed and set. but also be regularly inspected and serviced by specialist personnel.

2.6.7 OTHER EQUIPMENT

Other automatic fire-fighting equipment may be appropriate for certain systems in a high-rise building, such as transformers, electrical switchgear and control rooms, computer centers and telephone switchboards.

ADVANTAGES OF SKYSCRAPERS Ability to accommodate large populationsThe world's population, especially in Middle East and Asian countries, continues to migrate from

rural areas to urban areas. By 2030, it is expected that about 60% of the world’s population will be urban. In 2050, over 80% of the world population will live in urban areas when the world’s population is expected to reach 9 billion. (1)  Utilization of the vertical space in urban areas is the only way to accommodate the needs of this growing population. 

Economic Globalization The ongoing trend for constructing tall buildings around the world reflects the increasing impact

of global competition on the development of the world’s major cities. These cities compete on the global stage to have the title of tallest building with which to announce the confidence and global stature of their growing economies. An iconic tall building enhances the global image of the city. It is likely to put the city on the world map, thereby signaling and promoting its significant economic progress and advancement. (1)

Urban RegenerationAs people begin to better understand the impact their lifestyles have on our environment, many

young people are seeking a lifestyle that is less dependent on automobiles. They want to work, shop and recreate within walking distance of where they live. Older people are moving to cities seeking  lower maintenance properties, easy access to medical services and less isolation.  Construction of new attractive high-rises can also beautify and revitalize dilapidated districts and neighborhoods within the urban core and surrounding areas. This improves the quality of life in these areas by minimizing or eliminating social ills such as crime that might have been prevalent there. (1)

Agglomeration With an abundance of skyscrapers comes an abundance of businesses and consumers in a small geographic area. The presence of an abundance of firms offering similar products spurs competition, innovation, and efficiency. Agglomeration improves economy of scale and can increase productivity through access to denser markets. Access to competing suppliers helps firms procure more efficient, cheaper, and more appropriate inputs.(1)

Land Use and PreservationIn areas where land is expensive, building up provides the most efficient use of space for a

growing population. According to the Urban Land Institute, “By strategically increasing the number of dwelling units per acre, cities not only will go a long way toward meeting their sustainability objectives, but also will be competitive, resilient, and great places to live” (2) High density structures also help preserve open space such as: natural areas in and around cities and localities that provide habitat for plants and animals, recreational spaces, farm and

ranch lands, places of natural beauty, critical environmental areas (e.g., wetlands), and recreational community spaces.(1) 

Climate Change and Energy Conservation Although tall building require an enormous amount of energy to build, the long term advantages

make them more energy efficient. Tall buildings save energy relative to an equivalent floor area of low-rise buildings. They explained: “Manhattan can be considered the greenest place in America, if measured by energy use per inhabitant. If New York City were a state, it would be 12th in population and last in energy consumption” (3)

Infrastructure and TransportationVertically configured buildings facilitate more efficient infrastructure. Simply put, a 500-unit

single-family subdivision requires many more roads, sidewalks, sewers, hydro lines, power and gas lines, light standards, fire hydrants, etc., than that of a tall building, which allows integrating these systems efficiently in a dense manner. (1) Additionally, in areas with of high density, people can accomplish more with less driving. Not only is public transportation is more available, but most tasks such as shopping, banking, medical services and general errands are within walking distance. Overall, compact development reduces driving from 20% to 40%. (4)

Emerging TechnologiesThe development of skyscrapers has led to many engineering and technological advances.

Advancements in the areas of building service systems, computer sciences, facade engineering, glazing, daylight and heat control, structural framing systems, ceiling systems, lighting, ventilation, exit strategies and water recycling systems can all be attributed to skyscraper development. 

Local PrideSkyscrapers are also points of pride for a city and its citizens. The design of many skyscrapers

include beautiful public areas and allow the public to view public works of art. Public viewing platforms in iconic skyscrapers provide an economic boost to the area by drawing tourists year-round.

 DISADVANTAGES OF SKYSCRAPERS Economic ConsiderationsConstruction of these buildings requires an extra cost premium because of their need for

sophisticated foundations, structural systems to carry high wind loads, and high-tech mechanical, electrical, elevator, and fire-resistant systems (2) Skyscrapers also have higher operational costs such as higher operational costs, such as high energy consumption, elevator maintenance, and emergency response preparedness. Compared to low rise buildings, skyscrapers have less useable space. While about 70% of a skyscraper’s floor plate is generally usable space (the remainder being the building’s elevator core, stairwells, and columns), more than 80% of low-rise spaces are typically useable. (3)

Environmental ImpactWind funneling and turbulence around the base of skyscrapers can cause inconvenience for

pedestrians. The height of the building creates huge shadows blocking sunlight from nearby structures. 

Civic Infrastructure

Due to the density of population that skyscrapers create, demand on transportation and infrastructure are greatly increased. Proper planning to alleviate traffic congestion typically require large public works and construction projects. A new skyscraper will also place additional load on the existing power grid, water supply, and sewer systems. If a tall building is built in an undeveloped area, new cost-intensive infrastructure must be provided. (2)

Socio-Cultural FactorsMany scholars have expressed concerns about the socio-psychological impacts of living in high-

rise housing. While high-rise housing may be desirable for single people and couples, it may be less desirable for a family with children. Some sociologists argue that the environment of tall buildings can make inhabitants feel claustrophobic by creating a rat-cage mentality (2)

PerceptionSome poorly planned skyscrapers have created a public perception that the buildings are poorly built and lead to higher rates of crime in the area. One example of this is the  Pruitt-Igoe housing project in St. Louis. Researchers have identified economic class, race, poor planning, and linear blockish brutalist architecture as reasons for the failure of this project. (4)

Public SafetyEspecially after the September 11th attacks on the World Trade Center, people see skyscrapers

as targets for potential future attacks. This threat in addition to the possibility of more common disasters such as fire or earthquake make many people afraid to reside or work in or around skyscrapers. 

Global ConnectivityWhen skyscrapers were first built, one of the perceived advantages was to create connections

between diverse groups of people and allow them to work together more easily. With the advent of the internet, people can now work from anywhere and connect with anyone. This new technology may minimize the advantage of physical proximity. 

5. ARCHITECTS CONSIDERATION (CASE STUDIES)BURJ KHALIFA, DUBAI

Fig: 2.9 Buij Kalifa. Dubai

A mixed use development which has office, retail, hotels and residential spaces. The Burj Khalifa was revealed to be 828m (2.7 16ft) high, far high riser than the previous record holder, Taipei 101. With a total built-up area of about 6 million sq ft. Burj Khalifa features nearly 2 million sq ft of residential space and over 300.000 sq ft of prime office space, in addition to the area occupied by Armani Hotel Dubai and the Armani Residences. The tower also lays claim to the highest occupied floor, the high riseest service lift, and the world's highest observation deck on the 124th floor. The world's highest mosque and swimming pool will meanwhile be located on the 158th and 76th floors.

Bhurj Dubai includes 163 habitable floors plus 46 maintenance levels and 9 parking levels in the basement. The tapering spire is made out of reinforced concrete,steel, stainless steel

Official Name: Burj Khalifa Bin Zayed Also Known As: Burj Dubai Built: 2004-2010 Cost: $4,100,000,000 Designed By: Skidmore, Owings & Merrill Structural engineer : William F. Baker Main contractor: Samsung C&T Developer: Emaar Properties Type: Skyscraper Total Stories: 206 Inhabited Stories :106 Elevators: 57 , speed:10m/sc Maximum Height: 2,717 Feet / 828 Meters Total area: 4,000,000 sq.m Location: No. 1, Burj Dubai Boulevard, Dubai,

United Araband The model above shows the major components of the

500 acre Downtown Burj Dubaidistrict - showing the Dubai Mall at left – Burj Dubai Tower centre right – and The Old Town and Island to the left of the lake – and the  commercial and residential

towers around the periphery.

Project Details: Economy: size, scope, and cost:The key facts are:

1] 500 acre - 2 square kilometres [0.8 square miles] - mixed urban district. 2] 30000 homes in 19 residential towers.3] 9 hotels with 2000 keys including the 160 room Armani Burj Dubai.4] 3.77 million square feet of retail space in the Dubai Mall.5] 3.5 kilometre long Boulevard [see 4 on site plan above].6] 280 metres of fountains.7] 1400 car parking spaces at the Mall.8] 36 acre lake.6] 6 acres of designated parkland.7] US$20 billion total project investment and US$4.1 billion tower investment.

Designed by Skidmore, Owings and Merrill, the designers of the Sears Tower in Chicago and the Freedom Tower in New York, Emaar has also retained GHD – an international building consulting firm – as independent consultants.

The builders are Samsung Engineering and Construction who also built the PETRONAS Twin Tower in Malaysia and the Taipei 101 in Taiwan.

Comparison of Burj Khalifa with other skyscrapers

Burj Dubai Structure:As the following image shows the tower comprises three parts set around a central core.

As the tower gains height setbacks occur on each of the three parts in an upward spiraling pattern – so that the width of the tower deceases as it gets higher. The top of the tower is capped with a single spire.

Extensive views of the Arabian Sea have been achieved for most rooms on most levels by the Y shaped floor plan.

Burj Dubai footprint: The 80,000 sq ft [7432 sq meter] foundation slab has 192 piles buried 164 feet deep. Even with this massive piling the tower is projected to sway by up to 9 feet at its highest point:

The tower will be clad with reflective windows and aluminum and stainless steel fined panels designed to withstand the sometime 50+ degree heat of the Dubai summer.

The Fountain:Outside the tower a complex public fountain system has been commissioned from WET Design – a sUSA based company - who have designed an elaborate 900 foot high fountain that will project water 490 feet into the air whilst illuminated by 6600 lights and 50 colour projectors.

Floor

The

s2.7.2 CONCEPT

The architecture features a triple-lobed footprint, an abstraction of a desert flower named Hymenocallis.

The tower is composed of three elements arranged around a central core.

Twenty-six helical levels decrease the cross section of the tower incrementally as it spirals skyward.

The curves at each ends symbolising the onion domes – an essential element in Islamic architecture.

The modular. Y-shaped structure, with setbacks along each of its three wings provides an inherently stable configuration for the structure and maximizes views of the Arabian Gulf

Site Plan – showing the triangular podium base of the Burj Dubai tower and all 15principal components of the new Downtown Burj Dubai district:

1    Burj Dubai                                       2    Dubai Mall   3    The Old Town   4    Burj Dubai Boulevard – this extends for 3.5 kilometres around the tower periphery 

  5    The Residences [18 towers]   5a The Residences [18 towers]   6    Burj Dubai Lake Park   7    South Ridge [6 towers]   8    Burj Dubai business hub [6 low-rises]   9    Burj Dubai Lake hotel [63 storeys 300m] 10    Burj Dubai metro station 11    The Lofts [3 towers] 12    Burj Views [3 towers] 13    8 Boulevard Walk [38 storeys] 14    Doha Street    15    Sheikh Zayed Road

2.7.3 FOUNDATIONThe superstructure is supported by a large reinforced concrete mat. which is in turn supported by bored reinforced concrete piles. The mat is 3.7 meters thick, and was constructed in four separate pours totaling 12.500 cubic meters of concrete. The minimum centre-to-centre spacing of the piles for the tower is 2.5 times the pile diameter. The 1.5 meter diameter x 43 meter long piles represent the largest and longest piles conventionally available in the region.A high density, low permeability concrete was used in the foundations, as well as a cathodic protection system under the mat, to minimize any detrimental effects form corrosive chemicals in local ground water. It is founded on a 3.7m thick raft supported on bored piles, 1.5 m in diameter, extending approximately 50m below the base of the raft.

1. The three wings

2. Y shape3. The central

core

1

3

2

Fig: 2.11 Type of Foundation

The Gradient spiral of the tower levelsTop

level

Middle level

Lower level

Tower levelswind

wind

wind

The Advantages Of The Tower Shape Design

The Advantages :

Foundation : The Modular, Y-Shaped Structure, With Setbacks Along Each Of Its Three Wings Provides An Inherently Stable Configuration For The Structure And Provides Good Floor Plates For Residential.

Usage : The Y-Shaped Plan Is Ideal For Residential And Hotel Usage, With The Wings Allowing Maximum Outward Views And Inward Natural Light.

Nature : Gradient Spiral Design Hinders The Swirling Wind .Fig.1

9

76

1

7

211

3

4

5

8

10

67

Layout details:

1. Burj khalifa arrival court 10. Service Yard

2. Armani hotel entry 11. Office Entry

3. Residential entry

4. Viewing deck

5. Lake front

promenade6. Tower garden7. Water feature8. childern’s play area9. Recreation area

spire

Level 160 to 168

Level 40 to 42

Level 77 to108

Level125 to135

Level112 to121Level109 to111

Level 76

Level136 to138

Level 38 to 89

Level 15

5Level 139 to

154Level 12

4Level 12

3Level 12

2

Level 73 to 75

Level 44 to 72

Level 43

Level 156 to 159

spire

Level 160 to 168

Level 77 to108

Level125 to135

Level112 to121Level109 to111

Level 76

Level136 to138

Level 15

5Level 139 to

154Level 12

4Level 12

3Level 12

2

Level 73 to 75

Level 44

Level 156 to 159

The right wing :

Spire : Over 200m long and houses

communications equipment .

Level 156 to159 : Broadcast and telecoms companies .

Level 125 to 135 : The corporate suites .

Level 112 to 121 : The corporate suites .

Leve77 to108 : Private residences .

Level 76 : Sky lobby (fitness facilities, jacuzzi, swimming pools and recreational room) .

level 38 to 39 : Armani hotel Dubai .

Level 19 to37: The residence .

Level 9 to 16 : Armani residence .

Concourse, ground to level 8 : Armani hotel Dubai .

The left wing :

Level 139 to 154 : The corporate suites .

Level 124 : At the top observation deck

Level 123 : Sky lobby ( business lounge and library) .

Level 122 : At.mosphere restaurant .

Level 44 to 72 : The residence .

Level 43 : Sky lobby (fitness facilities, jacuzzi, swimming pools and recreational room) .

A : PODIUM : Provides a base ( 150m wide, six levels ) anchoring the tower to the ground . Provides separate entries for the corporate suites , residence and Armani Hotel .

B : Foundation

B1 and B2: Parking and mechanical

Level 44

adcdc

Amani hotel : 0-8 level

Residences : 17-37 levelArmani hotel : 38-39 level

Residences : 44-72 leveL

Private Residences : 77-108 leveL

Corporate suites

service elevator

The building is expected to hold up to 35,000 people at any one time.

Otis Elevators has installed 57 elevators, and 8 escalators.

33 high-rise elevators including 2 double-decks.

138 floors served by main service elevator.

504 meters – main service elevator rise, the world’s highest.

10 meters per second – speed of elevators .

60 seconds – approximate time from ground to level 124.

10.000 kilograms – weight of hoist ropes.

Softened corners

Tapering and setbacks

Varying cross-section shape

Spoilers

Porosity or openings

2.7.4.3 COMMUNICATION FLOORSThe top four floors have been reserved for communications and broadcasting. These floors occupy the levels just below the spire.

Fig: 2.21 Communication floors

2.7.4.4 MECHANICAL FLOORS Seven double-storey height mechanical floors house the equipment that bring Burj Khalifa to

life. Distributed around every 30 storeys, the mechanical floors house the electrical sub-stations,

water tanks and pumps, air- handling units etc. that arc essential for the operation of the tower and the comfort of its occupants.

2.7.4.5 OBSERVATION DECKAn outdoor observation deck, named At the Top. opened on 5 January 2010 on the 124th door. At 452 m (1.483 ft), it was the highest observation deck. Burj Khalifa opened the 148th floor SKY level at 555 m (1,821 ft), once again giving it the highest observation deck in the world on 15 October 2014.

Fig: 2.23 Aerial view from Observation deck

Fig: 2.25 Exterior Cladding

2.7.4.6 SPIRALThe crowning touch of Burj Khalifa is its telescopic spire comprised of more than 4.000 tons of structural steel. The spire was constructed from inside the building and jacked to its full height of over 200 metres (700 feet) using a hydraulic pump. The spire also houses communications equipment.

2.7.S EXTERIOR CLADDINGThe exterior cladding is comprised of reflective glazing with aluminum and textured stainless steel spandrel panels and stainless steel vertical tubular fins.Close to 26.000 glass panels, each individually hand- cut. were used.The cladding system is designed to withstand Dubai's extreme summer heatdfdsfdffd

2.7.S.1 CLEANINGCleaning of Burj is met by using custom made Building Maintenance Units [BMU]. While the pinnacle is reserved for specialised rope technicians. With al 18 BMU'S in operation, the facade will take two to three months to clean.

2.7.6 SERVICES

Seven double-storey mechanical floors house the equipment that bring Burj Khalifa to life. Distributed around every 30 storeys, the mechanical floors house the electrical sub-stations,

water tanks, pumps and air handling units that arc essential for the running of the building. These mechanical areas typically serve the 15 lloors above and below them. MEP operations are managed by a central BMS, with local control panels in each plant room,

all connected by fibre-optic cabling.

2.7.6.1 PLUMBING SERVICES The Burj Khalifa's water system supplies an average of 946.000 L (250.000 US gal) of water

per day through 100 km (62 mi) of pipes. An additional 213 km (132 mi) of piping serves the fire emergency system, and 34 km (2 1 mi)

supplies chilled water for the air conditioning system. The waste water system uses gravity to discharge water from plumbing fixtures, floor drains,

mechanical equipment and storm water, to the city municipal sewer.

ELECTRICITY

Fig: 2.26 Cleaning System

The tower's peak electrical demand is 36mW. equal to about 360.000 100 Watt bulbs operating simultaneously.

2.7.6.2 AIR CONDITIONING The air conditioning system draws air from the

upper floors where the air is cooler and cleaner than on the ground. At peak cooling times, the tower's cooling is

equivalent to that provided by 13.000 short tons (26.000.000 lb) of melting

ice in one day,or about 46 MW. ® The condensate collection system, which uses the hot and humid outside air, combined with the cooling requirements of the building, results in a significant amount ofs condensation of moisture from the air.

The condensed water is collected and drained into a holding tank located in the basement car park; this water is then pumped into the site irrigation system for use on the Burj Khalifa park.

Burj Dubai Lifts:The tower will have 56 elevators – most double deck elevators carrying 42 people – and accessible from two floors at the same time. Floor speeds of 10m/s

2.7.6.5 SKY LOBBIES

The Burj Khalifa features distinct sections: residential apartments, serviced apartments and hotel rooms, and corporate offices. Elevators have been arranged in zones to serve these different audiences, with 'sky lobby' system.

The sky lobby is an intermediate floor where residents, guests and executives will change from an express elevator to a local elevator, which stops at every floor within a certain segment of the building.

Burj Khalifa's sky lobbies are located on level 43. 76 and 123 and will include a lounge area and kiosk, amongst other amenities.

2.7.7 FIRE SAFETY

Concretes surrounds all stairwells and the building service and fireman's elevator will have a capacity of 5,500 kg and will be the world's high tallest service elevator.

There arc pressurized, air-conditioned refuge areas located approximately every 25 floors. First Application of "Lifeboat" evacuations Refuge levels: 42.75.111 & 138 10 elevators available for emergency evacuations

Fig: 2.28 Fire Safety Elevators

2.7.S LANDSCAPE

The park's 11 hectares of greenery and water features serve as both entry to Burj Khalifa and outdoor living space. The landscape design includes three distinct areas to serve each of tower's

three uses: hotel, residential and office space. The main entry drive is circled with a palm court, water features, outdoor spaces and a forest grove above. The grand terrace features garden spaces, all-around pedestrian circulation, custom site furnishings, a functional island and a lake edge promenade.

Fig: 2.29 Landscape Aerial View The landscape design includes six major water features: the main entry fountain.hotel entry fountain, residential entry fountain, the grand water terrace, children'sfountain pool and the sculptural fountain. The plants and the shrubbery will bewatered by the building's condensation collection system that uses water from thecooling system. The system will provide 68.000.000 L annually. Spectacular stonepaving patterns welcome visitors at each entry.

Fig: 2.30 Stone Paving Patterns

2.7.9 INFERENCES

The Burj is not only the tallest building in the world, it's also home to the highest observation deck, swimming pool, elevator, restaurant, and fountain in the world. ® Once at the top, visitors can enjoy temperatures that are nearly 15 degrees cooler

than at the building's base. Burj dubai has no helipad. All windows were fixed windows, no scope for natural ventilation

Records of Burj Khalifa

1. Tallest existing structure: 829.8 m (2,722 ft) (previously KVLY-TV mast – 628.8 m or 2,063 ft)

2. Tallest structure ever built: 829.8 m (2,722 ft) (previously Warsaw radio mast – 646.38 m or 2,121 ft)

3. Tallest freestanding structure: 829.8 m (2,722 ft) (previously CN Tower – 553.3 m or 1,815 ft)

4. Tallest skyscraper (to top of spire): 829.8 m (2,722 ft) (previously Taipei 101 – 509.2 m or 1,671 ft)

5. Tallest skyscraper to top of antenna: 829.8 m (2,722 ft) (previously the Willis (formerly Sears) Tower – 527 m or 1,729 ft)

6. Building with most floors: 163 (previously World Trade Center – 110) 7. Building with world's highest occupied floor8. World's highest elevator installation (situated inside a rod at the very top of the

building)9. World's longest travel distance elevators: 504m (1,654 ft)[23][24]10. Highest vertical concrete pumping (for a building): 606 m (1,988 ft) 11. World's tallest structure that includes residential space12. World's second highest outdoor observation deck: 124th floor at 452 m

(1,483 ft) When it first opened, the observation deck was the highest outdoor observation deck in the World, but it has since been surpassed by Cloud Top 488 on top of Canton Tower.

13. World's highest installation of an aluminium and glass façade: 512 m (1,680 ft) 14. World's highest nightclub: 144th floor15. World's highest restaurant (At.mosphere): 122nd floor at 442 m (1,450 ft)

(previously 360, at a height of 350 m (1,148 ft) in CN Tower) 16. World's highest New Year display of fireworks. 17. World's second highest swimming pool: 76th floor (world's highest swimming pool

is located on 118th floor of Ritz-Carlton Hotel at International Commerce Centre, Hong Kong).

SWISS REINSURANCE TOWER AT ST MARY AXELONDON

THE GHERKINNORMAN FORSTER

1