Raffles City Chengdu, China: achieving a sunlight-influenced design

Raffles City Chengdu is a large, new, mixed-used development in Chengdu, China's fourth biggest city. Known locally as ‘The Sliced Porosity Block', its complex, fragmented design was driven by a planning requirement for maximum penetration by sunlight. This paper describes the unique structural engineering challenges and solutions adopted for the 300 000 m2 development's five, irregularly shaped, 110 m tall towers, which feature a variety of cantilevered and sloping sections, large openings and link bridges. Extensive computer and physical modelling was done to evaluate seismic and wind resistance of the towers both during and after construction. The high-quality white concrete finish specified for the composite steel−concrete exoskeleton also required substantial care in designing and constructing the complex composite nodes, for which several mock-ups were built.