填充墙刚度贡献对结构位移计算的影响分析

The Influence of Infill Wall Stiffness on the Calculation of Structural Displacement

为了考虑填充墙刚度贡献对结构位移计算的影响,引入了考虑填充墙刚度时的结构刚度增大系数λ。按照底部剪力法,推导出考虑填充墙刚度影响后,基本周期位于T_g^5T_g的结构在多遇地震作用下的层间位移是减小的。λ取1.5的混凝土结构,位移与不考虑填充墙刚度的结构层间位移比值有理论上限值0.80。用实例及软件原理推导出常用设计软件考虑填充墙刚度后的位移相比纯框架是增大的,λ取1.5的混凝土结构二者之比的上限值为1.20。二者矛盾的原因在于,填充墙较均匀的结构在位移计算时,软件的处理方法过于保守。此时不考虑填充墙刚度贡献的位移计算结果即是偏于安全的。

A increscent coefficient of structure stiffness ＂λ＂was introduced to consider the stiffness of filled wall to the structural displacement. It is found that the structure＇s lateral seismic displacement is reduced by considering the role of infill walls when the structure＇s fundamental period is between Tg and five times Tg. The displacement ratio of infilled frame and pure frame has a theoretical maximum value 0.80 for the reinforced concrete structures when the λ value is 1.5. However the seismic displacement calculation result is enlarged by usual structure design software after considering the filler walls stiffness. The displacement ratio of infilled and pure frames calculated by software has another maximum value 1.20 for the same structures. The reason is that the software＇ calculation method is too conservative and the result is safe enough when not considering the filler walls stiffness.