The petronas twin towers

Architect: César Pelli
#Structure
#Architecture_Building
The Petronas Towers, also known as the Petronas Twin Towers, are twin skyscrapers in Kuala Lumpur, Malaysia. they were the tallest buildings in the world from 1998 to 2004 until they were surpassed by Taipei 101.

1. The Petronas Twin Towers AMAN SHUKLA 101116005 B.ARCH 2016-21’ NIT TRICHY

2. INTRODUCTION The Petronas Towers, also known as the Petronas Twin Towers (Menara Petronas, or Menar Berkembar Petronas), are twin skyscrapers in Kuala Lumpur, Malaysia. According to the Council on Tall Buildings and Urban Habitat (CTBUH)'s official definition and ranking, they were the tallest buildings in the world from 1998 to 2004 and remain the tallest twin towers in the world.

3. Quick Information ARCHITECT : Cesar pelli STRUCTURAL ENGINEER : Thornton thormaseti CONTRACTORS : TOWER 1 : Hazama corporation TOWER 2 : Samsung engg .& Co. FLOOR AREA : 3,95,000 m sq MATERIAL : Concrete , steel HEIGHT OF EACH TOWERS : 452 M above street level LIFTS : 29 double-decker high-speed passenger lifts in each tower.

4. Construction Team - Two separate construction teams. - First to use GPS (Global Positioning Satellite) - Built by concrete instead of conventional steel - 1000 people worked on each tower (3 shifts) - Floors up to 73rd Identical & easiest - 4 days to built each floor (Normal – 10 days) TOWER 1 Led by Japan  Hazama Corporation Started on March 1994 (25 months & 1 week) TOWER 2 Led by Korea  Samsung Engineering Co. Started on April 1994 (24 months) Highlights Two 88 story towers with, a connecting bridge The sky bridge connecting the two structures was also designed to act as a emergency escape in the case of terroristic attacks and fires Pinnacles on top of the towers – design to represent Islamic culture The use of glass windows Strive for the tallest building and originality

5. Foundation The geotechnical survey discovered that the actual construction site was situated partially over decayed limestone deposition and rest over soft rock. foundation was rested on 1To0 4 safe bed rock the piles were extended to depth ranging from (200-374) feet. To reach this depth, PETRONAS Tower became the structure having the deepest seated foundation of the world. The piles were embedded by thick raft. This raft was 15 feet in depth and it requires enormous amount of concrete to cast it. This is about 4470,000 cubic feet which was the largest continuously poured concrete until 2007. This huge quantity of concreting for each tower required 54 hours to pour.

6. Design Concept The towers evoke traditional motifs of Islamic art, honoring the Malaysian Muslim heritage, combined with innovative technology. Represent a change in the style of skyscrapers built in Kuala Lumpur, closer to traditional international style. Pelli used an Islamic geometric design in its plant, by interlacing two squares of gradually decreasing size at the top, which is based on a traditional motif in Islamic culture, a star of 12 peaks including a circle at each intersection.

7. Structure Structure is the most important element to ensure the strength and the stability of a building. Without a strong structure, the buildings is not safe to be occupied. These pictures show the cross section of the tower. The cross section shows TWO squares interlocking to each other to form an eightpoint star shape, which is the most common shape design in Islamic design.

8. Structure Geometry is used as the main concept of the design of Petronas Twin Towers. This design means:- Unity ( Perpaduan ) Harmony ( Harmoni ) Stability (Stabil) Rationality ( Rasional ) The roof uses a lot of triangular shape structure to give a better support to the building.

9. Structural System(for gravity and lateral loads): Structural system consists with75-by-75 foot concrete cores and an outer ring of widely-spaced super columns. The core structure of each tower is composed of a ring of sixteen cylindrical columns of high strength reinforced concrete. The columns vary in size from2.4in diameter at the lower areas to 1.2meters in diameter at the top ,and are placed at the outside corners. The columns arel inked with a series of concrete core walls and ring beams. These movement-resistant and damper-free structures can be described as a pair of “soft tubes”. There are actually two concentric pressurized cores in The structures, and the two cores unite at the 38th floor of each tower.

10. Skybridge DOUBLE DECK BRIDGE SPANNING 58.4 m CONNECTS TWO TOWER AT SKYLOBBY ELEVATOR TRANSFER STATION ON FLOOR 41 AND 42 EASY CIRCULATION B/W UPPER TOWER FLOORS MINIMIZE LIFT USAGE REDUCES FIRE EXIT REQUIREMENT GREAT HEIGHT AND SPAN REQUIRES STEEL FOR LIGHT WEIGHT AND EASY CONST. TWO HINGED ARCH SUPPORTS THE SPAN SELF CENTRING ACTION FROM RESTRAIN AT ARCH CROWN AND SPHERICAL PIN AT SUPPORTS

11. Skybridge The skybridge built between the two towers uses the combination of rectangles and triangles structure to add more strength and stability to the bridge The top view from skybridge of petronas twin tower. It shows the landscape of roof design of near by buildings. It portrays an interesting symmetrical design.

12. Pinnacle

13. Material Used High-strength concrete was used in the central core, perimeter columns, perimeter ring beams and outrigger beams. The towers and their base are clad with stainless steel extrusions and custommade 20.38 millimetre laminated lightgreen glass. The sunscreens have cast aluminium end caps and are fixed on brackets made of extruded aluminium and finished with oven-cured PVF2 fluorocarbon paint.

14. Steel Type Type 316 stainless steel( Ferrous ) was employed to clad the exterior of the Petronas Towers, Malaysia (and the Jin Mao Tower in China). Type 316 stainless steel is often used in marine applications like for boat fittings, and also used in the food and beverage industry. Silos, cheese vats, fruit tanks and wine tanks are also made using this type of steel.

15. Time The construction was estimated to take 8 years, however there was an eight month delay It was completed in 6 years, two years under what was predicted It was vital that the building was constructed to the management plan, as it would cost $700,000 per day after the deadline

16. Execution During the execution stage, the scope and schedule are identified and determined. The schedule allowed for 4 days of construction per floor, it initially took 8 day, they had to construct uninterrupted, 24 hours a day, 7 days a week Construction began in early 1993. A site establishment is conducted during this stage, however, the engineers discovered that there had never been a proper analysis of the site, the site came to a standstill.

17. Execution Geologist looked for bedrock, but found that the sitewas on declayed limestone and on the edge of cliff The site was proposed to be moved 60 meters onto the softer ground, were they could build their own bedrock consisting of concrete The sky bridge connecting the two towers was design for emergency purposes, such as a terrorist attack, fires, and other emergencies

18. Constrains The not suitable bedrock (foundation) A lack of steel The concrete was not suitable, too soft They had to create a new form od concrete that acted the same as steel; strong with a degree of flexibility Flooring was time consuming

19. Issues during construction Issue One – The foundation slab If the concrete dried unevenly, the slab would crack, thus seriously weaken the ability to support the building above. Therefore, they decided to pour the concrete all at the once, scheduling concrete trucks to arrive every 2,5 minutes for 52 hours, without a break. Issue Two – The weather The Malaysian weather is susceptible to torrential rain, this is also problematic to the slab, as the concrete can get too wet, and become ruined. They covered the entire slab with canvas, the equivalent to 56 circus tents