Optimal Design of Super-Tall Structures Based on the Sensitivity of Stiffness-Weight Ratio

Abstract:

The overall stability is the essential requirement of the structural design of super-tall buildings. A single driven constraint optimization design method based on the sensitivity of the stiffness-weight ratio was proposed to control the P-Δ effect (additional effect of gravity caused by horizontal deformation of structure) of super-tall buildings. Stiffness-weight ratio, the ratio of stiffness to gravity load, is an important parameter that affects the P-Δ effect. Based on the principle of virtual work and the method of equal increment analysis, the formulas of sensitivity coefficients were deduced, and the sensitivity coefficients of a two-story plane frame were calculated as an example. The feasibility of the proposed method was verified theoretically. Finally, the proposed method was applied to a super-tall building with a building height of 468 meters. And after adjusting the dimensions of components, a total cost of 9.391 million yuan was saved. The feasibility of the proposed method was illustrated by this engineering case. The results show that the proposed method can reasonably distribute the materials to different component groups for a super-tall building structure with the stiffness-weight ratio as a driven constraint, which can realize the economical and practical structural design.

Key words:structural design;super-tall building;sensitivity analysis;optimization of stiffness-weight ratio;equal increment analysis