斜梯板双层配筋的混凝土框架楼梯间单元地震响应分析

以混凝土框架结构中常见的板式楼梯间单元为研究对象,按照梯板单层配筋和双层配筋建立两种有限元模型,通过模态分析以及多遇地震和罕遇地震的动力时程分析,研究梯板双层配筋的影响。分析表明,楼梯间单元表现出较为明显的扭转特征,小震时两种模型的动力反应基本相同,大震下两种模型的梯板破坏存在较大差异,梯板的钢筋截断会形成薄弱环节,而双层配筋则可以避免梯板在整体结构破坏前被拉断,梯板两端支座处塑性应变较大,梯梁、框架柱、梯柱在半休息平台处均出现明显的破坏。

Analysis of seismic response of the concrete frame unit with doubly reinforced staircase

This article takes the common concrete frame unit with staircase as research object.We create two kinds of finite element model,one of which is singly reinforced staircase while the other is doubly reinforced staircase,in order to study the impact of double reinforcement.After the modal and time-history analysis,we see that the staircase unit twists obviously.And the dynamic response of the two models under the minor earthquake is more or less the same.When the models confront with the rare earthquake,the damage situation is very different with each other.Weak points will be formed around the section of the cut rebar,and the doubly reinforced staircase can make the ladder board safe before the damage of the frame.On both end of the ladder abroad,the plastic strain is obvious.Obvious damage can also be found in ladder beam,frame columns and ladder columns at halfspace.