Structured by Modern Methods

The composite steel / concrete structure is an impressive feat of engineering. The building not only has to support its own colossal weight but must also withstand typhoons and earthquakes. The subtropical humidity brings clouds that cloak the top of the structure during much of the relatively cool winter.

Built on a site just 650 feet (200 meters) from a fault line, the 101 Tower has been structured with pioneering features. An 800-ton (725,000-kilogram), 18-foot- (5.5-meter-) diameter sphere on the 88th floor is part of a tuned mass dampening (TMD) system. The primary structure is flexible to withstand earthquakes, and the sphere hangs like a pendulum that swings to counteract the movement created in the flexible structure by high winds, thus dampening the resonance in the building and providing stabilization (Fig. 2.3).

 

a - the suspended sphere which absorbs movements from typhoons and earthquakes

b - cross section of the top of the tower with the huge sphere that acts as a stabilizing pendulum

Figure 2.3 - The huge steel sphere of the tuned mass dampening system

 

The hanging ball of the TMD also forms a tourist attraction in the observatory at the top of the building, which offers spectacular views of the city. One million visitors a year are expected to visit the "Topview Taipei" observatory, reachable by the world's fastest elevator that goes from the ground floor to the 1150-foot- (352-meter-) high viewing area in just 37 seconds. The fastest elevators in the tower travel at 55 feet (17 meters) per second.

The tower's structure is a steel box frame, toward the center of which are 16 steel plate columns, each filled with concrete up to the 62nd floor for added strength. Close to each of the four exterior walls, up to the 26th floor, are two "super-columns," two "sub-super-columns," and two corner columns. The super- and sub-super-columns are filled with reinforced 10,000-psi concrete.

The architects are confident that this structural solidity will not compromise floor layout flexibility. At the top of the building, for example, where the floor plan is much smaller, the loading transfers directly to the core columns, thus providing support while allowing for column-free interior planning.