Petronas Towers

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

PETRONAS TOWERS A study by, Jonathan Tedjakusuma Gautam R Shenoy First Year M.B.S Fall 2001 Term Project

ARCHITECTURAL DATA Skybridges : Center line Span - 191 feet Overall Width - 17 feet Overall Height - 31 feet Length of Supports - 169 feet Total Weight - 720 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)

PETRONAS PETRONAS TOWERS TOWERS

PETRONAS PETRONAS TOWERS TOWERS

ARCHITECTURAL DATA

FACT SHEET uFoundation

: 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) uArchitect

: Cesar Pelli & Associates

uLocation

: Kuala Lumpur, Malaysia

uStructural

uThe perimeter diaphragm wall : 2 ft 6 in thick uStructure : A core and Cylindrical tube Frame System, constructed entirely of Cast in place, high strength concrete (Up to Grade 80)

Engineer : ThorntonThornton-Tomasetti Engineers, NY & Ranhill Bersekutu Sdn. Bhd., Kuala Lumpur

uFloor framing at Tower Levels : Concrete Fill on composite steel floor deck and composite rolled steel framing

uMEP

Engineers : Flack + Kurtz, New York, USA; KTA Tenaga Sdn. Bhd., Kuala Lumpur, Malaysia PETRONAS PETRONAS TOWERS TOWERS

PETRONAS PETRONAS TOWERS TOWERS

ARCHITECTURAL DATA uHeight

uNumber uGross

uSize

Transportation : Double deck and Sky Lobby systems. Floors 8 to 37 are served by 2 banks of 661600/1600kg double deck elevators. Floors 44 to 83 are served by 1 bank of 6and 6-1600/1600kg, 2 banks of 33-1600/1600kg double deck elevators. Skylobbies (Floor 41 to 42) are served by 52100/2100kg double deck shuttle elevators.

of Floors : 88 (occupiable)

Building Area : 2.3 million sqft. (each tower)

uHeight

of the Pinnacle : 241 feet

of floor plate (gross) : Lower Floors - 28,239 sqft ; Upper Floors - 22,490 sqft to 10,000 sqft

uTypical

floor to floor height : 13 feet 2 inches

uFinished uRaised

PLANNING ANALYSIS uVertical

of the Towers : 1,482.6 feet (above street level)

Ceiling Height : 8 feet 8 inches

Floor : 5 inches (Floor 8 to Floor 72)

uSkylobby

: Levels 41 and 42 (includes, Conference Center, Dining Facilities and a prayer room) PETRONAS PETRONAS TOWERS TOWERS

PETRONAS PETRONAS TOWERS TOWERS

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PLANNING ANALYSIS uFloor Planning : The Floor plan design was originated from the ancient Islamic forms of eighteight-pointed stars and decorative motifs. When viewed in plan, the towers appear as two overlapping squaressquares-interlocking heaven and earth - to create an eighteight-pointed star, which is further refined with half circle between the star points.

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

W24 x 131 (Beam) Tube Section 1(Column) W24 x 306 (Beam)

uExterior 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 of days and months throughout the year.

Tube Section 3 (Column) W24 x 207(Beam) Tube Section 2 (Column) W24 x 408 (Beam) Tube Section 4 (Column) Tube Section 5 (Column) - On the last 5 floors

PETRONAS PETRONAS TOWERS TOWERS

PETRONAS PETRONAS TOWERS TOWERS

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

CASE ANALYSIS W24 x 131 (Beam)

uThe Structure was treated as a Complete Steel Frame instead of its composite nature uThe

Type was Moment Frame

uThe

Section types used are Tubular and ‘I’ Beams

Analysis two Floors were treated as One and the structure was studied

uFor

uThe

Gravity Load is calculated as 4.9 kips/ft

uThe

Lateral Load is calculated as 16.2 kips/ft

uthe

total number of floors is 42

uTapering

occurs at 21st, 21st, 31st and 37th floors PETRONAS PETRONAS TOWERS TOWERS

PETRONAS PETRONAS TOWERS TOWERS

CASE ANALYSIS

CASE ANALYSIS Tube Section 1(Column) - Super Petro 5

The analysis was divided into the following parts : The first case is where in the structure was detailed in Multi Frame 4D and Analyzed uThe second case is where in Belt Trusses were added to the structure and then it was analyzed in Multi Frame again uThe third case is analysis by reducing the size of members as the belt truss affects the system uAll the cases were studied and notes were made on the DEFLECTION, STRESSES IN MEMBERS, RATIOS OF DEFLECTION TO HEIGHT uThe comparisons show how the addition of Belt Trusses can affect the cost factor as well stability of the structure uEach

case will be discussed in the following slides

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PETRONAS PETRONAS TOWERS TOWERS

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CASE ANALYSIS W24 x 207(Beam)

CASE ANALYSIS Tube Section 3 (Column) - Super Petro 3

PETRONAS PETRONAS TOWERS TOWERS

PETRONAS PETRONAS TOWERS TOWERS

CASE ANALYSIS

CASE ANALYSIS W24 x 408 (Beam)

Tube Section 2 (Column) - Super Petro 4

PETRONAS PETRONAS TOWERS TOWERS

PETRONAS PETRONAS TOWERS TOWERS

CASE ANALYSIS W24 x 306 (Beam)

CASE ANALYSIS Tube Section 4 (Column) - Super Petro 2

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PETRONAS PETRONAS TOWERS TOWERS

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Tube Section 5 (Column) - Super Petro 3n

CASE ANALYSIS

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

Stress for Inner Beam = 18.107 ksi (Floor 30)

Stress for Inner Column = 12.390 ksi (Floor 29)

Step 4 - Stresses at the Third Offset

Stress for Outermost Beam = 6.743 ksi (Floor 37)

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

PETRONAS PETRONAS TOWERS TOWERS

PETRONAS PETRONAS TOWERS TOWERS

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

Stress for Inner Column = 11.557 ksi (Floor 37)

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

Step 1 - Stresses at the Bottom

Stress for Central Beam = 9.588 ksi (Floor 37) Stress for Bottom Beam = 14.557 ksi (Floor 01)

Stress for Bottom Column = 19.477 ksi (Floor 01)

Top Portion

Step 5 - Stresses at the Top

Step 2 - Stresses at the First Offset

Stress for Top Beam = 7.447 ksi (Floor 42)

Stress for Outermost Beam = 10.473 ksi (Floor 21)

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PETRONAS PETRONAS TOWERS TOWERS

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

Stress for Outermost Column = 9.617 ksi (Floor 20)

Stress for Outer Column = 7.020 ksi (Floor 42)

CASE ANALYSIS ANALYSIS FOR CASE 1

Stress for Inner Beam = 4.743 ksi (Floor 21)

Step 3 - Stresses at the Second Offset

uFloor to Floor height - 20 feet uNumber of floors - 42 uOverall Height - 840 feet uOffset at Each Level - 6 feet on either side uDeflection - 27.912 inches (Y(Y-axis) uDeflection - 02.133 inches (X(X-axis)

Deflection Ratio : Ratio Along Y - Axis = 361.134 > 200

Stress for Outermost Beam = 17.883 ksi (Floor 30)

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PETRONAS PETRONAS TOWERS TOWERS

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CASE ANALYSIS

CASE ANALYSIS Case 2 - Addition of three belt trusses

Case 2 - Addition of three belt trusses uThe belt trusses are added at Levels, 21, 30 and 37 uThe members used are XP12 sections with weight of 65.477 LB/Ft

37 30 21

Stress for Edge Column = 6.566 ksi (Floor 42)

Stress for Middle Beam = 6.988 ksi (Floor 42)

ANALYSIS FOR CASE 2

uFloor to Floor height - 20 feet uNumber of floors - 42 uOverall Height - 840 feet uOffset at Each Level - 6 feet on either side uDeflection - 24.312 inches (Y(Y-axis) uDeflection - 02.022 inches (X(X-axis) Ratio Along Y - Axis = 414.610 > 200 PETRONAS PETRONAS TOWERS TOWERS

PETRONAS PETRONAS TOWERS TOWERS

CASE ANALYSIS Case 2 - Addition of three belt trusses

Stress for Bottom Column = 13.712 ksi (Floor 01)

CASE ANALYSIS Case 3 - Addition of One belt truss

Stress for Bottom Beam = 14.631 ksi (Floor 01)

Stress for Bottom Column = 18.238 ksi (Floor 01)

Stress for Bottom Beam = 14.631 ksi (Floor 01)

21

Stress for Column under Truss = 9.366 ksi (Floor 21)

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

Stress for Column under Truss = 9.228 ksi (Floor 21)

PETRONAS PETRONAS TOWERS TOWERS

PETRONAS PETRONAS TOWERS TOWERS

CASE ANALYSIS Case 2 - Addition of three belt trusses

Stress for Beam under Truss = 1.137 ksi (Floor 21)

CASE ANALYSIS Case 3 - Addition of One belt truss

Stress for Edge Column = 8.590 ksi (Floor 30)

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

Stress for Column under Truss = 5.547 ksi (Floor 37)

Stress for Beam under Truss = 2.961 ksi (Floor 37)

PETRONAS PETRONAS TOWERS TOWERS

Stress for Edge Column = 8.239 ksi (Floor 30)

Stress for Column under Truss = 4.905 ksi (Floor 37)

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

Stress for Beam under Truss = 2.576 ksi (Floor 37)

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CASE ANALYSIS

Case 3 - Addition of One belt truss

Stress for Edge Column = 7.219 ksi (Floor 42)

CASE ANALYSIS Case 4 - Analysis of One belt truss (Change the size of Members)

Stress for Middle Beam = 7.657 ksi (Floor 42)

Stress for Bottom Column = 20.099 ksi (Floor 01)

Stress for Bottom Beam = 19.309 ksi (Floor 01)

ANALYSIS FOR CASE 3

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uFloor to Floor height - 20 feet uNumber of floors - 42 uOverall Height - 840 feet uOffset at Each Level - 6 feet on either side uDeflection - 24.768 inches (Y(Y-axis) uDeflection - 01.374 inches (X(X-axis) Stress for Column under Truss = 20.599 ksi (Floor 21)

Ratio Along Y - Axis = 406.976 > 200

Stress for Beam under Truss = 17.234 ksi (Floor 21)

PETRONAS PETRONAS TOWERS TOWERS

PETRONAS PETRONAS TOWERS TOWERS

CASE ANALYSIS

CASE ANALYSIS Case 4 - Analysis of One belt truss

Case 4 - Analysis of One belt truss (Change the size of Members) I. After the cases 1,2 and 3, we realized that addition of 3 Belt Trusses was not required since the deflection varies only in terms of a few inches uDeflection - 24.312 inches (Y(Y-axis) for the case with three belt trusses uDeflection - 24.768 inches (Y(Y-axis) for the case with One belt trusses

Stress for Edge Column = 15.899 ksi (Floor 30)

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

II. Hence the next case which involves the resizing of members and checks for stresses to be within 22 Ksi, will be conducted on the Single Belt Truss reinforced frame Stress for Column under Truss = 20.843 ksi (Floor 37)

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

PETRONAS PETRONAS TOWERS TOWERS

Case 4 - Analysis of One belt truss (Sections used)

CASE ANALYSIS Column D Beam 1 Column C Beam 2 Column B Beam 3

PETRONAS PETRONAS TOWERS TOWERS

Case 4 - Analysis of One belt truss

CASE ANALYSIS

ANALYSIS FOR CASE 4

uFloor to Floor height - 20 feet uNumber of floors - 42 uOverall Height - 840 feet uOffset at Each Level - 6 feet on either side uDeflection - 28.590 inches (Y(Y-axis) uDeflection - 02.063 inches (X(X-axis) Ratio Along Y - Axis = 352.570 > 2004

Column A

TABULATION OF VARIOUS MEMBER TYPES AND SIZES

Beam 4

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CONCLUSION : • The use of a single Belt Truss provides enough resistance • The size of all members can be reduced • Yet, Stresses remain within the limit of 22 KSI • 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 - Old and New

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

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