WORLD TRADE Center structural engineer Leslie Robertson has claimed his latest redesign of the long delayed Shanghai World Financial Centre 'reaches to the highest level in economy, strength, stiffness and robustness'.
Robertson made the claims during his IStructE Gold Medal address in London last week.
He said the client wanted an extra 15% of fl oor space - but the redesign would have to use the foundations for the original design. These had been installed in the late 1990s before a financial crisis led to a shelving of the project.
Height will also increase, from 460m to 493m. The project had been through the hands of three other structural engineering practices by the time Leslie Robertson Associates were called in to work with architect Kohn Pedersen Fox.
Meeting these new, more onerous conditions could only be done by a complete redesign of the structural system, Robertson said. 'Previous designers used a moment-resistant space frame at the façade, with closely spaced columns of considerable size.
'We chose to use no more than three columns on each face and keep them slim by using three storey outrigger trusses every 12 fl oors to transfer the column loads to the core. The fi al design is reminiscent of a pair of bent leaves cantilevered from the ground and cross braced for additional stiffness.' Robertson's presentation to an audience of around 250 covered his entire career, including the World Trade Center. He urged young designers in particular never to design an ugly structure, even when the structure would ultimately be hidden from view. 'Handsome structures are usually more efficient than ugly structures, ' Robertson said.
At the end of his address Robertson was awarded an honorary Fellowship of the IStructE.