增层改造与加固砌体结构抗震可靠性向量分析

Seismic Reliability Vector Analysis of Story-adding Retrofitting and Strengthening Masonry Structure

根据考虑中介状态的结构可靠性向量理论,认为砌体结构具有"安全-中介-失效"三级工作模式,这里的"中介"状态即为砌体结构带"故障"工作状态。由此,提出了一种加层改造及其加固砌体结构抗震性能的分析方法。根据地震作用引起的结构底部水平地震剪力的概率分布服从极值Ⅱ型的特点,选取以单片墙抗剪强度和楼层平均抗剪强度为计算指标,分别建立了砌体结构的单片墙和楼层的可靠性向量计算方法。采用该方法分析了一增层改造砌体结构,得到不同计算指标条件下原结构、加层改造结构的可靠性向量,同时计算了加固后结构的可靠性向量,为砌体结构的抗震性能评价和加固设计提供决策依据。

According to the theory of reliability vector of structure with intermediate state,it is assumed that masonry structure has three-stage work modes of safety,intermediate and failure.The intermediate state means the state when the structure works with trouble.Based on this,an analysis method for seismic performance of story-adding retrofitted and strengthened masonry structure is put forward.The probabilistic distribution model of seismic loads of masonry structure fits Extreme Value TypeⅡ,and shear strength of wall and mean shear strength of story are chosen to be calculation indexes,based on which calculation methods are put forward respectively to calculate the reliability vector of walls and stories of the masonry structure.This method is used to analyze a story-adding retrofitting masonry structure,and the reliability vector of the unretrofitted and story-adding retrofitted structure is calculated under different calculation indexes.In addition,reliability vectors are developed for the strengthened structure,which can offer decisive data to assessment of seismic performance and strengthening design.