Datong Art Museum

Assignment:  Write a memo on the design of a specific gravity structural system.  Indicate significant features the system was trying to solve and the methods used to address the issue. 

The Datong Art Museum has a pyramidal space truss roof.

The Datong Art Museum has a pyramidal space truss roof.  The space truss roof can span very large spans and space.  The 40m high roof composed of four interconnected pyramids supported on a series of inclined, two-layer steel space trusses.  The spans range from 75 to 130 m.  The art museum program calls for large open space so the museum can display large-scale works of contemporary art.  This dedicated space is called the Grand Gallery, the museum’s center piece.   The Grand Gallery is a large, column free exhibition space that will be 37 m tall and features a clear span of about 90m.  Architect Norm Foster led the design.    Wang Chun Guang and Yang Jie were the structural engineers for the project.  Most of the building is underground to a depth of 12m.  .  The pyramidal space truss erupts from the ground. 

The tilting planes in the roof achieve a simpler structural concept than a conventional beam and column solution.  Each space truss will consist of two planar trusses from hollow circular steel sections; the main chord member is 400 mm in diameter.  The truss depth ranges from 7 to 16 m.  Yang describes the four pyramidal structures as a fusion of each individual pyramid, forming an integrated enclosure.  The engineers noted the long-span trusses providing the vertical loading support system and “the so-called spatially penetrated joint connections in the trusses bearing the axial loads and transferring the lateral forces”.          

The bracing element will be added to the roof ridge and the main roof edge connections, enabling the trusses to work as a loop beam, the engineers explained.  This technique will stabilized and strengthen the roof structure.  The reinforced-concrete shear walls varying in height from 7 to 13 m and from 300 to 500 mm thick act as the plinth for the roof truss structure.  Their location is permanent so these shear walls crate the circulation channels within the museum galleries.  The foundation system is made of piles.  The piles are 800 to 1,000 mm in diameter.  The pile depth ranges from 10 to 15 m.  Because most of the building is underground, the building needs to be protected against groundwater intrusion.  The design features a water cavity, waterproof concrete, and other waterproofing materials.    

References:

Reid, Robert L. (2012, December). Datong Art Museum Will Feature Pyramidal Space Truss Roof. Civil Engineering, 82(12), 24-27.