Long-span structures are usually challenging in themselves. But coupled with being on top of four 63-story towers makes it uniquely complicated. Every step of this grandiose project called for an innovative solution, beginning with a double-decker truss that carried the weight of luxury penthouses while spanning 200+ feet between towers. The planar truss was not straight but curved, inducing additional forces that had to be accounted for in design.
Tall buildings are especially sensitive to wind. The project’s layout and presence of two 80-story towers in the vicinity caused “turbulence” in the four towers. Aseemingly simple solution was to connect all the 4 towers with the capping bridge, which is unprecedented. However, the analysis program’s limitation of solving only one million analysis equations had to be overcome which required months of extensive study to reduce the complex structural engineering model for the tower design into simplified, calibrated models, saving considerable analysis and design time.