基于剪重比敏感性的超高层结构优化设计方法

为保障建筑物最低抗震安全性的要求，地震作用下结构系统受剪承载力不应过小，GB 50011—2010《建筑抗震设计规范》中提出了剪重比指标。由于地震影响系数在长周期段下降较快，超高层结构在地震作用下的基底剪力及楼层剪力偏低，导致其剪重比指标往往无法满足规范要求。通过对剪重比约束下构件尺寸的敏感性分析，研究以最小成本满足剪重比指标的优化设计方法。依据虚功原理和等增量分析方法推导了敏感性系数公式，并以简单框架结构为例验证了两种敏感性分析方法的有效性。并将上述敏感性分析方法用于建筑高度为468 m的某超高层建筑，结果表明，以敏感性为指引对剪重比控制的超高层结构进行优化设计，共节约材料成本1141.99万元，具有较好的经济效益。

Optimal design method of super tall building based on sensitivity of shear-weight ratio

Considering that the shear capacity of the structural system should not be too small to ensure the minimum seismic safety of buildings, the shear-weight ratio was proposed in GB 50011—2010 ‘Code for seismic design of buildings’. Because of the rapid decrease of seismic influence coefficient for structures with a long period, the base shear force and floor shear force of super tall structures under earthquakes are low, which leads to the situation that the shear-weight ratio cannot be satisfied. In this paper, through the sensitivity analysis of the component size with the constraint of the shear-weight ratio, the optimal design method to meet the requirement of shear-weight ratio at the minimum cost was studied. Based on the principle of virtual work and the equal increment analysis method, the sensitivity coefficient formulas were derived, and the effectiveness of the two sensitivity analysis methods was verified by taking a simple frame structure as an example. Then, the sensitivity analysis method was applied to a 468 m super high-rise building. The results show that the material cost of the super tall building controlled by the shear-weight ratio is optimized by using the sensitivity analysis method, and the material cost is saved by 11.4199 million RMB, which has good economic benefits.