Petronas Towers

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PETRONAS

TOWERS

A study by,

Jonathan Tedjakusuma

Gautam R Shenoy

First Year M.B.S Fall 2001 Term Project

UNIVERSITY OF SOUTHERN CALIFORNIA, Los Angeles UNIVERSITY OF SOUTHERN CALIFORNIA, Los Angeles Master of Building Science Program Master of Building Science Program ARCH 613 : Structures Research ARCH 613 : Structures Research

PETRONAS TOWERS PETRONAS TOWERSPETRONAS TOWERS

u

uArchitect : Cesar Pelli & AssociatesArchitect : Cesar Pelli & Associates u

uLocation : Kuala Lumpur, MalaysiaLocation : Kuala Lumpur, Malaysia u

uStructural Engineer : ThorntonStructural Engineer : Thornton--Tomasetti Tomasetti

Engineers, NY

Engineers, NY & &

Ranhill Bersekutu Ranhill Bersekutu Sdn. Bhd., Kuala Sdn. Bhd., Kuala Lumpur Lumpur u

uMEP Engineers : Flack + Kurtz, New York, MEP Engineers : Flack + Kurtz, New York,

USA; KTA Tenaga Sdn.

USA; KTA Tenaga Sdn. Bhd., Bhd.,

Kuala Lumpur, Malaysia

FACT SHEET

u

uHeight of the Towers : 1,482.6 feet Height of the Towers : 1,482.6 feet

(above street level)

(above street level) u

uNumber of Floors : 88 (occupiable) Number of Floors : 88 (occupiable) u

uGross Building Area : 2.3 million sqft. Gross Building Area : 2.3 million sqft.

(each tower)

(each tower) u

uHeight of the Pinnacle : 241 feetHeight of the Pinnacle : 241 feet u

uSize of floor plate (gross) : Size of floor plate (gross) :

Lower Floors

Lower Floors --28,239 sqft ; 28,239 sqft ;

Upper Floors

Upper Floors --22,490 sqft to 10,000 sqft22,490 sqft to 10,000 sqft u

uTypical floor to floor height : 13 feet 2 inchesTypical floor to floor height : 13 feet 2 inches u

uFinished Ceiling Height : 8 feet 8 inchesFinished Ceiling Height : 8 feet 8 inches u

uRaised Floor : 5 inches (Floor 8 to Floor 72)Raised Floor : 5 inches (Floor 8 to Floor 72) u

uSkylobby : Levels 41 and 42 Skylobby : Levels 41 and 42

(includes, Conference Center,

Dining Facilities and a prayer room)

ARCHITECTURAL DATA

PETRONAS TOWERS PETRONAS TOWERSPETRONAS TOWERS Skybridges : Center line Span

Skybridges : Center line Span --191 feet191 feet Overall Width

Overall Width --17 feet17 feet

Overall Height

Overall Height --31 feet31 feet

Length of Supports

Length of Supports --169 feet169 feet

Total Weight

Total Weight --720 tons720 tons

Exterior Cladding : Horizontal Ribbons of

Vision Glass and Stainless Steel Spandrel

Panels

Foundation : Two Raft Foundations, 15 feet thick,

each containing 13,000 cu meters of Grade 60

Concrete which weighs approximately 32,350 T

with 208 Barrette Piles (rectangular section piles,

9x4 feet, varying from 197 feet to 380 feet deep)

ARCHITECTURAL DATA

PETRONAS TOWERS PETRONAS TOWERSPETRONAS TOWERS u

uFoundation : Foundation :

Two Raft Foundations, 15 feet thick,

each containing 13,000 cu meters of

Grade 60 Concrete which weighs

approximately 32,350 T with 208

Barrette Piles (rectangular section

piles, 9x4 feet, varying from 197 feet

to 380 feet deep)

to 380 feet deep) u

uThe perimeter diaphragm wall : The perimeter diaphragm wall :

2 ft 6 in thick

2 ft 6 in thick u

uStructure : Structure :

A core and Cylindrical tube Frame

System, constructed entirely of Cast in

place, high strength concrete (Up to

Grade 80)

Grade 80) u

uFloor framing at Tower Levels : Floor framing at Tower Levels :

Concrete Fill on composite steel floor

deck and composite rolled steel

deck and composite rolled steel framing

ARCHITECTURAL DATA

PLANNING ANALYSIS

u

uVertical Transportation : Vertical Transportation :

Double deck and Sky Lobby

systems.

systems. Floors 8 to 37 are served by Floors 8 to 37 are served by

2 banks of 6

2 banks of 6-

-1600/1600kg double

1600/1600kg double deck deck

elevators.

elevators. Floors 44 to 83 are Floors 44 to 83 are

served by

served by 1 1

bank of 6

bank of 6--1600/1600kg, 1600/1600kg, and and 2 banks of 3

2 banks of 3--1600/1600kg1600/1600kg double deck double deck

elevators.

elevators. Skylobbies (Floor 41 to Skylobbies (Floor 41 to

42) are served 42) are served byby 55- -2100/2100kg double deck 2100/2100kg double deck shuttle elevators. shuttle elevators.

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PLANNING ANALYSIS

u

uFloor Planning : The Floor plan design was originated from the Floor Planning : The Floor plan design was originated from the

ancient Islamic forms of eight

ancient Islamic forms of eight--pointed stars and decorative motifs. pointed stars and decorative motifs. When viewed in plan, the towers appear as two overlapping

When viewed in plan, the towers appear as two overlapping

squares

squares--interlocking heaven and earth interlocking heaven and earth --to create an eightto create an eight--pointed pointed

star, which is further refined with half circle between the star

points.

points. u

uExterior facade : The exterior facade is made from glass, Exterior facade : The exterior facade is made from glass,

aluminum and stainless steel panels which brings a tremendous

light effect from the sun light and it changes on different time

light effect from the sun light and it changes on different timeof of days and months throughout the year.

days and months throughout the year.

CASE ANALYSIS

To Study the Structure, analyze the Structural members To Study the Structure, analyze the Structural members and suggest changes, certain assumptions had to be and suggest changes, certain assumptions had to be made. The following were the assumptions: made. The following were the assumptions:

u

uThe Structure was treated as a Complete Steel Frame instead The Structure was treated as a Complete Steel Frame instead

of its composite nature

of its composite nature u

uThe Type was Moment Frame The Type was Moment Frame u

uThe Section types used are Tubular and ‘I’ BeamsThe Section types used are Tubular and ‘I’ Beams u

uFor Analysis two Floors were treated as For Analysis two Floors were treated as

One

and the structure and the structure

was studied

was studied u

uThe Gravity Load is calculated as The Gravity Load is calculated as 4.94.9kips/ft kips/ft u

uThe Lateral Load is calculated as The Lateral Load is calculated as 16.216.2kips/ftkips/ft u

uthe total number of floors is the total number of floors is 4242 u

uTapering occurs at Tapering occurs at 21st21st, , 31st31stand and 37th37thfloorsfloors

CASE ANALYSIS

The first case is

The first case iswhere in the structure was detailed in Multi where in the structure was detailed in Multi

Frame 4D and Analyzed

Frame 4D and Analyzed u

uThe second case is where in Belt Trusses were added to the The second case is where in Belt Trusses were added to the

structure and then it was analyzed in Multi Frame again

structure and then it was analyzed in Multi Frame again u

uThe third case is analysis by reducing the size of members as The third case is analysis by reducing the size of members as

the belt truss affects the system

the belt truss affects the system u

uAll the cases were studied and notes were made on the All the cases were studied and notes were made on the DEFLECTION, STRESSES IN MEMBERS, RATIOS OF

DEFLECTION, STRESSES IN MEMBERS, RATIOS OF

DEFLECTION TO HEIGHT

u

uThe comparisons show how the addition of Belt Trusses can The comparisons show how the addition of Belt Trusses can

affect the cost factor as well stability of the structure

affect the cost factor as well stability of the structure u

uEach case will be discussed in the following slidesEach case will be discussed in the following slides The analysis was divided into the following parts : The analysis was divided into the following parts :

CASE ANALYSIS

BASE CASE :

BASE CASE :What are the Steel Sections used ?What are the Steel Sections used ?

W24 x 131 (Beam) Tube Section 1(Column)

W24 x 207(Beam) Tube Section 2 (Column)

W24 x 306 (Beam)

W24 x 408 (Beam) Tube Section 3 (Column)

Tube Section 4 (Column) Tube Section 5 (Column)

- On the last 5 floors

CASE ANALYSIS

W24 x 131 (Beam)

CASE ANALYSIS

Tube Section 1(Column) - Super Petro 5

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CASE ANALYSIS

W24 x 207(Beam)

CASE ANALYSIS

Tube Section 2 (Column) - Super Petro 4

CASE ANALYSIS

W24 x 306 (Beam)

CASE ANALYSIS

W24 x 408 (Beam)

CASE ANALYSIS

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CASE ANALYSIS

Tube Section 5 (Column) - Super Petro 3n

Note: The Beams used in this area are W24 x 408

CASE ANALYSIS

The analysis was conducted and the following Stresses have The analysis was conducted and the following Stresses have been Recorded for

been Recorded forEXISTING CASEEXISTING CASE Step 1

Step 1 --Stresses at the BottomStresses at the Bottom

Stress for Bottom Beam = 14.557 ksi (Floor 01)

Stress for Bottom Column = 19.477 ksi (Floor 01) Step 2

Step 2 --Stresses at the First OffsetStresses at the First Offset

Stress for Outermost Beam = 10.473 ksi (Floor 21)

CASE ANALYSIS

Step 2

Step 2 --Stresses at the First Offset (Continued)Stresses at the First Offset (Continued)

Stress for Outermost Column = 9.617 ksi (Floor 20)

Stress for Inner Beam = 4.743 ksi (Floor 21) Step 3

Step 3 --Stresses at the Second OffsetStresses at the Second Offset

Stress for Outermost Beam = 17.883 ksi (Floor 30)

CASE ANALYSIS

Step 3

Step 3 --Stresses at the Second Offset (Continued)Stresses at the Second Offset (Continued)

Stress for Inner Column = 12.390 ksi (Floor 29)

Stress for Inner Beam = 18.107 ksi (Floor 30) Step 4

Step 4 --Stresses at the Third OffsetStresses at the Third Offset

Stress for Outermost Beam = 6.743 ksi (Floor 37)

Stress for Inner Column = 11.557 ksi (Floor 37)

PETRONAS TOWERS PETRONAS TOWERSPETRONAS TOWERS Step 5

Step 5 --Stresses at the TopStresses at the Top

CASE ANALYSIS

Step 4

Step 4 --Stresses at the Third Offset (Continued)Stresses at the Third Offset (Continued)

Stress for Central Beam = 9.588 ksi (Floor 37)

Top Portion

Stress for Top Beam

= 7.447 ksi (Floor 42) Stress for Outer Column= 7.020 ksi (Floor 42)

CASE ANALYSIS

u

uFloor to Floor height Floor to Floor height --20 feet20 feet

u

uNumber of floors Number of floors --4242

u

uOverall Height Overall Height --840 feet840 feet u

uOffset at Each Level Offset at Each Level --6 feet on 6 feet on either sideeither side

u

uDeflection Deflection --27.912 inches (Y27.912 inches (Y--axis)axis)

u

uDeflection Deflection --02.133 inches (X02.133 inches (X--axis)axis) ANALYSIS FOR CASE 1 ANALYSIS FOR CASE 1

Deflection Ratio :

Ratio Along Y

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CASE ANALYSIS

Case 2

Case 2 --Addition of three belt trussesAddition of three belt trusses

u

uThe belt trusses are added at Levels, 21, 30 and 37The belt trusses are added at Levels, 21, 30 and 37 u

uThe members used are XP12 sections with weight The members used are XP12 sections with weight of 65.477 LB/Ft of 65.477 LB/Ft 21 21 30 30 37 37 PETRONAS TOWERS PETRONAS TOWERSPETRONAS TOWERS

CASE ANALYSIS

Case 2

Stress for Bottom Column

= 13.712 ksi (Floor 01) Stress for Bottom Beam= 14.631 ksi (Floor 01)

Stress for Column under

Truss = 9.366 ksi (Floor 21) Stress for Beam under Truss = 1.211 ksi (Floor 21)

CASE ANALYSIS

Case 2

Stress for Edge Column

= 8.590 ksi (Floor 30) Stress for Beam under Truss= 1.603 ksi (Floor 30)

CASE ANALYSIS

Stress for Edge Column = 6.566 ksi (Floor 42)

Stress for Middle Beam = 6.988 ksi (Floor 42)

u

uFloor to Floor height Floor to Floor height --20 feet20 feet u

u

uOverall Height Overall Height --840 feet840 feet

u

uDeflection Deflection --02.022 inches (X02.022 inches (X--axis)axis) Ratio Along Y

Ratio Along Y --Axis =Axis =414.610 > 200414.610 > 200

Case 2

ANALYSIS FOR CASE 2 ANALYSIS FOR CASE 2

CASE ANALYSIS

21

Case 3

Case 3 --Addition of One belt trussAddition of One belt truss

CASE ANALYSIS

Case 3

Stress for Beam under Truss= 1.598 ksi (Floor 30)

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CASE ANALYSIS

Case 3

Stress for Middle Beam = 7.657 ksi (Floor 42)

u

uDeflection Deflection --01.374 inches (X01.374 inches (X--axis)axis) Ratio Along Y

CASE ANALYSIS

Case 4

Case 4 --Analysis of One belt trussAnalysis of One belt truss

(Change the size of Members)

I. After the cases 1,2 and 3, we realized that I. After the cases 1,2 and 3, we realized that addition of 3 Belt Trusses was not required since addition of 3 Belt Trusses was not required since the deflection varies only in terms of a few inches the deflection varies only in terms of a few inches -

-u

uDeflection Deflection --24.312 inches (Y24.312 inches (Y--axis) for axis) for the case with the case with three belt trusses

three belt trusses

u

uDeflection Deflection --24.768 inches (Y24.768 inches (Y--axis) for axis) for the case with the case with One belt trusses

One belt trusses

II. Hence the next case which involves the II. Hence the next case which involves the resizing of members and checks for stresses to resizing of members and checks for stresses to be within 22 Ksi, will be conducted on the Single be within 22 Ksi, will be conducted on the Single Belt Truss reinforced frame

Belt Truss reinforced frame

CASE ANALYSIS

Case 4

Case 4 --Analysis of One belt trussAnalysis of One belt truss (Sections used) (Sections used) Column A Beam 4 Column B Beam 3 Column D Beam 1 Column C Beam 2

TABULATION OF VARIOUS MEMBER TYPES AND SIZES TABULATION OF VARIOUS MEMBER TYPES AND SIZES

CASE ANALYSIS

Case 4

(Change the size of Members)

21

CASE ANALYSIS

Case 4

Stress for Beam under Truss= 20.725 ksi (Floor 30)

Stress for Column under Truss = 20.843 ksi (Floor 37)

Stress for Beam under Truss = 19.898 ksi (Floor 37)

CASE ANALYSIS

u

uOffset at Each Level Offset at Each Level --6 feet on 6 feet on either sideeither side u

u

uDeflection Deflection --002.063 inches (X2.063 inches (X--axis)axis) Ratio Along Y

Case 4

CONCLUSION : CONCLUSION : •

•The use of a single Belt Truss provides enough resistanceThe use of a single Belt Truss provides enough resistance •

•The size of all members can be reduced The size of all members can be reduced •

•Yet, Stresses remain within the limit of 22 KSIYet, Stresses remain within the limit of 22 KSI •

•The deflection does change / increase by 3 inches in the new The deflection does change / increase by 3 inches in the new structure, but material costs are greatly reduced

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CASE ANALYSIS

Comparison of Members

Comparison of Members --Old and NewOld and New

Existing weight PSF = 71psf Redesign Weight PSF = 65 psf