Hi! I’m ~~A~~ and I 'll explain the history and characteristics of the Petronas Towers. I will separate this post in six parts:
1. Introduccion
2. History
3. Features of the structure (Materials, Shape, Type of structure, What specific features have been taken into account and resolved.)
4. Curiosities
5. Conclusion
6. Webgraphy
   
I hope you like it!!!

1. Introduction
The Petronas Towers were designed to be the centrepiece of a larger complex called the Kuala Lumpur City Centre (KLCC), a mixed-use development.

2. History: 

Much more than just an office building, the Petronas Twin Towers sparked a nation 's pride and came to symbolize Malaysia' s jaunt into the 21st century.

Petronas Towers are unquestionably the symbol of modern Malaysia. 

To represent Malaysia 's increasing wealth and the nation' s desire to feature more prominently on the international stage, it was decided to build a pair of landmark 88-storey towers to house the offices of the national oil and gas company, Petronas.

They were designed by architect Cesar Pelli and completed in 1998.

With 88 floors, the concrete structure and glass evoke the most traditional motifs of Islamic art, honoring the Muslim heritage of Malaysia. Pelli Islamic geometric design used in the plant to weave two squares, gradually decreasing in size at the top, which is based on a very traditional motif in Islamic culture: a star of 12 peaks including a circleat each intersection. 

Notable dates:
March 1993 -Excavation work begins.

March 1994 -Excavation and foundation for Tower One complete; construction begins.

April 1994 -Excavation and foundation for Tower Two complete; construction begins.
May 1995 -Pre-assembled Skybridge arrives from South Korea.

August 1995 -Skybridge is lifted into place.

February 1996 -Topping-out of both towers is completed.

March 1996 -Installation of pinnacles for both towers.

April 1996 -Petronas Towers officially declared the world’s tallest buildings.

3. Features of the structure: 

Vital Statistics: 

Location: Kuala Lumpur, Malaysia

Completion Date: 1998

Height: 1,483 feet

Stories: 88

Materials: Concrete, Steel

Facing Materials: Aluminum, Stainless Steel
Architect: César Pelli
Developer: KLCC Holdings Sdn Bhd
Structural engineer Thornton Tomasetti

Main contractor: 

Tower 1: Hazama Corporation

Tower 2: Samsung Engineering & Construction and Kukdong Engineering & Construction City Center: B.L. Harbert International.

Fast Facts:

• It took 36,910 tons of steel to build the Petronas Towers. That's heavier than 3,000 elephants!

• It takes 90 seconds to travel from the basement parking lot to the top of each tower.

• Together, the towers have 32,000 windows. It takes window washers an entire month to wash each tower just once!

The floor-plate of the Tower is designed based on geometric patterns common in architecture of Islamic heritage. It is composed of two rotated and superimposed squares with small circular infills. 

Like the exterior design, the Towers' entrance design was also inspired by the country's cultural heritage, incorporating contemporary Malaysian motifs adapted from traditional handicrafts such as songket and timber carvings. The overall character of the building is high-tech and international but distinctively Malaysian.

Skybridge The skybridge is an essential functional component linking the Twin Towers to facilitate movement between the two towers. 

The 58.4 meters double-decked skybridge is located at levels 41 and 42 joining the sky lobbies situated in both towers.

Engineering Design The structural system selected utilises a 'two-hinge arch' springing from supports at level 29 and rising at 63 degrees to support a pair of parallel two-span continuous bridge girders at Level 41.

The structure of the two-level bridge is conventional framing constructed of structural steel with beams moment-connected to columns which bear on the level 41 continuous girders. The bridge is 58.4 m long and weighs about 750 tonnes. The two-hinge arch supporting the bridge has rotational pins (spherical bearings) at the end of each leg or 'spring point' and at the top or 'crown' of the arch (bearings). The main bridge girders have a rotational (centering) pin directly over the arch crown to permit the crown to rise and fall as the Towers move closer or further apart.

WHAT DO YOU THINK IT IS MADE OF?
Petronas towers have 88 floors of reinforced concrete and steel and glass cover.

The external housing is stainless steel. A system of vertical depth, modulates umbrellas forms and produces a three-dimensional facade appropriate for the tropics.

WHAT ARE DIFFERENTS PARTS? Elements of the structure...

Type of structure

This skycraper is a Frame structure because is constituted by elongate members (beams, columns, bars, crossbars, cables...) forming a frame.

Based initially had the form of a octonary or what is the same: a eight-pointed star.

What specific features have been taken into account and resolved?

To meet local safety construction codes, the towers had to be able to withstand 65 miles for hour (105 km/h) winds. To assure this requirement would be fulfilled, the engineers tested the towers twice within a wind tunnel, first by computer simulation and second by building an actual model of the towers.

STRESSES IN THE STRUCTURE:
Tension, compression and bending


Tension:

•In the beams there are tension because it hold the bridge.






Comprenssion:

• In the towers and in the beams there are compression because the beams hold the bridge and the towers on them.




Bending:

• At the top of the buildings there are bending because the air apply forces on the towers.









STABILITY, RIGIDITY AND RESISTANCE

• This structure is made rigid by : the form of the building and the bridge.
• This structure is made stable by :the bridge, the beams and the foundations.

• This structure is made resistant by : strongs materials (steel and glass).

4. Curiosities: 

Petronas Twin Towers were the tallest buildings in the world until 2004, when Taipei 101 took over the title.

Petronas Towers are still the tallest twin buildings in the world.

The foundation of Petronas Twin Towers is as much as 120 m deep and was built by Bachy Soletanche.


The overall height of Petronas Towers is 451.9m (1483ft), from street level.


The sky-bridge of Petronas Twin Towers is at 41st and 42nd level and is 58.4m (192ft) long. It weighs 750 tons.

There are 10 escalators in each building of Petronas Towers.

The entry to Petronas Towers is free, but only a limited number of timed tickets are provided on a daily basis.


It cost $1.2 billion to build Petronas Towers.
Petronas Twin Towers also include an art gallery, an 840-seat concert hall, and an underground parking lot.



Alain "Spiderman" Robert, a French urban climber, tried to climb the Petronas Towers on 20th March 1997, with his bare hands and feet. He reached the 60th floor, where he was arrested by the police. He again tried the feat, this time on the other building, on 20th March 2007. This time also, he managed to reach only 60thfloor and was arrested by the police.

5. Conclusion: 

This has been a fantastic experience and I have learned about the construction of today. The Petronas Towers are a important skycraper of Malaysia but I had never heard about them. But now I think that they are fantastical towers and we need to know about them.

6. Webgraphy:

• Goggle images
• http://www.petronastwintowers.com.my/tickets#ticket_priceç
• http://www.engineering.com/ArticlesPage//Petronas-Twin-Towers.
• https://en.wikipedia.org/wiki/Petronas_Towers
• http://www.petronastwintowers.com.my/
• http://www.skyscraper.org/TALLEST_TOWERS/t_petronas.htm