Expo Axis, Expo 2010

Shanghai

structural engineering, special structures Services

SBA International Architect

Membrane roof and free-form bar structure

Project

The landmark of Expo Shanghai 2010 was the central boulevard – called the “Expo Axis” with one of the world's largest membrane construction, a 1,000 m long and 100 m wide axis from which visitors were guided to the theme and country pavilions. With an area of 350,000 m², the central entrance was the main entrance to the Expo, the China Pavilion, the Theme Pavilion, the Expo Center and the area along the Huangpu River. The sustainability concept still includes the preservation of the “Expo Axis”, with four further buildings after the mega-event – which will also stand for the urban center of a new district of Shanghai in the future.

Six freely shaped steel-glass structures with funnel-shaped geometry

Steel-Glass Construction

The roof structure consists of six funnel-shaped steel-glass constructions with a membrane structure in between. The funnels are made of a node-member-system with rectangular hollow sections and star-shaped nodes, which were welded on site. The geometry of the funnels was developed using form-finding tools; the member grid was generated with RhinoScript, following the force-density method, with the goal of ensuring optimal load flow while minimizing variance in glass sizes and rod lengths.

1000 m long and 100 m wider membrane roof construction

Membrane Construction

The membrane roof, covering an area of 65,000 m², is supported by 19 inner and 31 outer masts and is additionally anchored to the funnel-shaped “Sun Valleys.” The PTFE membranes are primarily tensioned between edge cables, diagonal cables, and the roof’s low points. The cable structure was pre-tensioned at the cable ends, and the membrane edges were subsequently carefully drawn to the cables.