超高层结构基于刚重比敏感性的优化设计方法

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

摘要:

结构整体稳定是超高层建筑结构设计的基本要求。为控制超高层建筑结构的重力P?Δ效应（结构的水平变形引起的重力附加效应）不至于过大，提出一种基于刚重比敏感性的单驱动约束优化设计方法。刚重比，即结构的刚度和重力荷载之比，是影响重力P?Δ效应的重要参数。依据虚功原理和等增量分析方法，分别推导敏感性系数公式，并以两层平面框架为例计算其敏感性系数，从理论上说明了方法的可行性。将该优化方法用于建筑高度468 m的某超高层建筑，调整构件尺寸后共计节约成本939.1万元，从工程实践上说明了方法的可行性。研究表明，针对以刚重比为驱动约束的超高层建筑结构，该方法能合理地将材料分配到不同的构件组中，可实现经济有效的结构设计。

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.