The new Museum extends to over 65,000m2 and includes exhibition space for Natural History, History and Folk, and an 800 seat Chinese Shadow Play Theatre, as well as a 1000m2 Temporary Exhibition space. A huge challenge was to provide 30m clear span exhibition halls with a structure capable of withstanding an earthquake measuring up to 8 on the Richter scale. Sections of the building also cantilever over the subway network tunnels. The solution was a rigid diagrid steel lattice that forms the structural shell.
The building sits on the West side of Tian-Fu Square – a new central focus of Chengdu. It presents an East façade of commensurate scale and proportion to embrace and address the huge scale of this new square and establishes a strong formal relationship to it with a simple enclosing rectilinear profile. The building celebrates this relationship to the monumental public space by extending an internal promenade of public foyers and circulation behind the entirety of the veiled façade.
It also envelops a new undercover outdoor public space - a monumental gateway through the building. Here, people can gather, cultural events can take place and even the local street market extends through to the square. This also creates an important connection between the C16th Huang Cheng Mosque, the most significant in South West China, and the main square.
A PRECIOUS SKIN OF COPPER ALLOY
The long narrow site is exploited to give all the public areas a dramatic relationship with the new square via the East elevation. The remaining three façades then enclose the largely hermetic exhibition halls, represented as a giant crafted artefact in the city cloaked in a precious skin of copper alloy rigorously profiled to play with light, shade and texture whilst accommodating all the technical requirements for ventilation grilles. Aside from the East face this skin is ‘lifted’ to reveal glazing at street level, allowing a more intimate human scale and relationship with the interior.
The skin forming facades and roof is expressed as one homogeneous material – a golden copper alloy which holds its colour well with age – but designed in such a way that it modulates and folds to present a variety of qualities. This is done through the tessellation of the skin profile and the arrangement of solid and perforated mesh panels, arranged to suite functional requirements inside.
The solid panels catch the sunlight dependent on their orientation and the mesh panels positioned where openings are required or where mechanical equipment needs to be ventilated. Meanwhile, the Eastern face is protected by a skin of perforated copper alloy mesh on a tension cable facade, coordinated with the folding geometry to maximise views out across the square. This also provides shading for the interior from the harsh glare of the Eastern sun and mediates the foyer spaces between outside glare and the dimmer environment of the exhibition halls.