Pudong and Shanghai World Financial Center

by Paul Koppen

 

Pudong

Pudong used to be namely farmland and countryside until 1990. In this year the Chinese government decided to set up a ‘Special Economic Zone’ in the district. The western tip of the Pudong district was designated to be the new financial centre of the modern China, called the ‘Luijazui Finance and Trade Zone’. Several landmark buildings were constructed in this zone during the 90’s to raise the image of the area. These include the Oriental Pearl TV Tower and the Jin Mao Building. Even now a lot of buildings are being constructed in this area. Personally I have never seen so much skyscrapers being constructed at once. One of these skyscrapers is the Shanghai World Financial Tower.                                                     

Image 1.1: Skyscrapers are popping out of  the ground in Pudong.

Shanghai World Financial Tower

Introduction

The Shanghai World Financial Tower is a supertall skyscraper that has been intermittently under construction in Shanghai. It is a mixed use skyscraper which will consist of office spaces, hotel rooms, conference rooms, observation decks and shops on the ground floors. The tower was originally planned for construction in 1997, but this was temporarily interrupted by the Asian Financial Crisis in the late 90’s and later to accommodate the design changes by the developer. The tower, which has 101 stories, is designed by Kohn Pederson Fox. The Shanghai World Financial Tower’s height has been set at 492 meters and this height will be reached around September 2007. The final completion will be at the beginning of 2008 and it will temporarily be one of the tallest skyscrapers in the world.

                                                                                                                                                                                   

Image 2.1: The SWFC  with the tube-structure  which is still visible.

Construction

The Shanghai World Financial Tower is a very tall tower from which the floor plans that are at the lower levels have a size from 58 meters by 58 meters. There can be concluded that it is a slim tower and that it is a difficult business to transfer the lateral forces down to the foundation. In short, how is there taken care of the stability.

Applying a tube-structure for extreme tall buildings is a common phenomenon. A tube-structure is in fact a spatial truss which stands up vertically. It is located at the façade of the building.

Image 2.2: The structural system of the building

The vertical columns of the tube-structure are located at the corners of the building and consist of steel columns which are afterwards being encased in reinforced concrete.

To connect the mega columns with each other there were belt trusses applied. These trusses are made of steel and there are 7 of these trusses to be found in the building. Not only does this belt truss have a constructive function, it also has a safety function. This is in case of an emergency. If there is a case where the building has to be evacuated, the people will then get together at the belt truss and then leave the building. These trusses are as high as one story and they count as very safe floors. In this way the construction of the building and the safety of it are beautifully combined.

The last elements of the tube-structure are the mega braces. These are connected with the mega columns and the belt trusses. They transfer loads that are carried with the mega columns, belt trusses and other elements of the building to the entire building. These loads will be divided.

Not only by applying a tube-structure is the stability of this building guaranteed, but also by applying a core wall. This core wall has a size about 30 meters by 30 meters and it reaches to the 79th floor of the building. The core wall will be constructed with steel encased reinforced concrete. Pursing the highest grade in safety, the tube-structure in the Shanghai World Financial Tower will be connected with the core wall. There are two ways of ensuring the stability of the building. This system is called the dual lateral force system and it is ideal for tall buildings and is designed to be much safer and more robust during earthquakes and typhoons compared to a single lateral force system, which resists forces only with perimeter columns and beams.

The tube-structure is connected to the core wall with the outrigger trusses. These outrigger trusses are located at three different levels in the building. Each outrigger truss is as high as three stories. At the first two levels where these outrigger trusses are applied, there are also the sky lobbies located. These levels are at the 28th, 29th floor and at the 52nd, 53rd floor of the building. The sky lobbies are as high as two stories. Functionality is beautifully combined with the construction of the building.

The reason why the core wall only reaches till the 79th level is because the hotel starts here. The hotel needs another floor plan than the other functions that are located in the building. And it couldn’t use a core wall in its floor plan. For this section of the building only the tube-structure takes care of the stability.

 The section above the hotel is the observatory. The construction of the last three floors of the hotel, the penthouses, and the observatory is completely made out of steel. These are in total 11 floors. The reason because of this is that the stability of the building is already ensured. The steel framework is only connected to the stable structure. The use of steel also works weight reducing and because of the fact that there are only a few more levels, there isn’t much pressure to resist by the construction. The choice to make it out of steel is a logical one. It is also easy to create the characteristic aperture in steel. If in another way constructed it would be a very difficult task.

 

 Image 2.3: The SWFC divided in different sections.

Elevators 

In such a tall building a lot of people have to go up to one of the many stories. The tower has 91 elevators in total to transport this large amount of people. If traditional elevators would have been used, the already small amount of free floor space would have been even smaller. The floor plan would mostly consist of a large amount of elevators. This problem is being solved by stacking two elevator cars. By doing this, it is possible to transport twice as many people in one ride with the minimal use of floor space. By stacking two elevator cars the traveling time is reduced to a minimum during rush hours, when the amount of people that need to be transported is at its peak. Stacking two elevators cars is a system successfully deployed in skyscrapers around the world.

 

Image 3.1: Two elevator cars are being stacked to transport the largest amount of people possible.

Image 3.2: All the different elevators that are in the building.

Please take notice of the elevators that are at each side of the characteristic aperture.

 


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