Construction Update: Shanghai Tower

Shanghai Tower construction charges forward on schedule; we are on track to open by the end of 2014. When complete, Shanghai Tower will be the second-tallest building in the world, at 632 meters and with 121 occupied floors. I sat down with Dick Fencl, technical director for the project, to talk over where we are now.

Quick stats on Shanghai Tower's construction progress as of April 2011:

• Tower floor framing: up to the 4th floor
• Tower core steel reinforcement: up to the 18th floor
• Tower core concrete: up to the 15th floor

 

Q: This shot is a little grey because it was taken from inside the Jin Mao Tower. It looks like this is a photo of the tower core construction. Can you explain how we're building it?

A:  This image begins to show how we're slip forming the core. What that means is that we're using a repetitive formwork system to place the concrete core. As we complete one level, we slip the form up to pour the next level.

The scale and immensity of the job site are staggering. The openings in the construction slab you can see in this image are left to insert equipment including electrical transformers as well as the beginnings of the construction of ramps to access below-grade parking. The red roof tops are on-site housing for construction workers.

Q: The scale of the project is certainly evident here, with the Jin Mao Tower and World Financial Center in the background. When Shanghai Tower is complete, it will be taller than both of these. Can you explain what's happening in this shot, on the level that will become the ground plane?

A: This level presented a particular challenge for the design team. The concrete slab you see here sits atop retail space, which required high ceilings. Yet this level will also create the ground plane, on which we'll plant trees, grass and landscaping. All of these demands typically require stairstepped elevations at varying heights. Shanghai Tower sits in a seizmic zone, so Chinese building code wisely required us to minimize the number of elevation changes we made to the ground plane, so that the site and tower are very stable in the event of an earthquake. It was a balancing act to juggle these varying demands.

Q: These brighly-colored elements reappear throughout the construction photos. What are they?

A: The quick answer is that the brightly-colored elements are all temporary; they're the equipment we're using to build the tower. Yellow elements are scaffolding, the green is a protective barrier. The red towers are part of the construction cranes for the site. In this image, they're lifting a portion of the floor edge structure.

This is another great shot showing the slip forming of the core. You can clearly see the solid formwork at the top of this shot, and beneath, the concrete core that's complete. The openings in the core are left for elevator doors, which give you a sense of the sheer immensity of the project.

Q: What a view these construction workers must have! It looks like they're sitting on a portion of the bamboo scaffolding, which is typical of Shanghai construction sites. Can you explain why there are holes in the grey structural beams at the top of this image?

A: The grey beams at the top of this shot are floor beams, and the openings in them enable us to run ductwork and utilities through them. The massive steel supercolumns in gold are in the background of this shot. 

Richard Fencl is a Principal at Gensler, and Technical Director for our North Central region. Dick loves to talk building technology, and delights in explaining concepts ranging from the best way to create a water resistant building envelope (harder than it looks) to why we place concrete—we never pour it! Got a question about the best way to detail a building? Contact him at richard_fencl@gensler.com.