带水平加强层的框架-核心筒结构有限刚度分析

Analysis of Limited Stiffness for Frame-core Tube Structure with Horizontal Outriggers

加强层可以增加结构的整体刚度,但同时使结构在加强层处出现刚度突变,随着加强层刚度的增加,刚度突变越明显,对结构产生不利影响越大。针对这种不利影响,一些学者提出了有限刚度加强层的概念,本文即对高层框架-核心筒结构的加强层的有限刚度进行了研究。文中采用底部剪力法计算在地震作用下,带加强层框架核心筒结构的顶点水平位移,通过计算不同加强层广义刚度与核心筒广义刚度比下结构顶点水平位移,来研究加强层广义刚度对结构整体刚度的影响。结果表明:只有当加强层广义刚度与核心筒广义刚度比在一定范围内,才会对结构侧移减小产生明显效果;而当加强层广义刚度与核心筒广义刚度比增大到一定值后,则对减小结构侧移影响不显著。

Strengthened storey can improve the whole rigidity of the structure, but meanwhile, it also causes rigidity abrupt change of the structure on the strengthened storey. With rigidity of the strengthened storey increasing, rigidity abrupt change is more obvious and adverse effect on the structure is greater. Based on the adverse effect, strengthened storey with limited rigidity was put forward by some scholars. In this paper, the limited rigidity of the strengthened storey of the high-rise frame-core wall structures is studied, and the top horizontal displacement of the structure with strengthened storey is calculated by base shear method under seismic action. The impact of the generalized stiffness of strengthened storey on the whole rigidity of the structure is researched by the means of analyzing relationship between the top horizontal displacement of the structure and the limited rigidity ratio of strengthened storey to core wall. The results show that only when the ratio of generalized stiffness of strengthening layer and generalized rigidity of the core tube is in the certain range, it will reduce the structural displacement; and when the ratio increases to a certain value, then the effect on reducing displacement of the structure is not significant.