基于损伤分级的底框结构抗震可靠性分析

Structure seismic reliability analysis based on injury classification

底部框架上部混凝土多孔砖砌体结构是一种复合结构形式,在地震作用下两部分结构的损伤状态及其概率可能不同。因此,本文将两种结构形式的"破坏指标"分别用于其结构损伤程度的标定,并考虑地震烈度的发生概率,以此为基础探讨抗震可靠度的分级计算方法。通过对一幢底框结构案例的分析,说明该方法有效实现了抗震可靠度分析的精细化,突破了传统可靠度计算中首超破坏机制对结构破坏判断的单一性限制,适用于复合结构多级风险的量化分析。

Bottom frame structure with concrete perforated brick masonry above the upper levels is a kind of com- plex structure. Seismic injury stage and probability of the two-part structure could be different. Therefore, the ＂damage index＂ of the two structures are used for calibration of structural damage stage. At the same time the prob- ability of earthquake intensity is considered in this paper. Based on these two, the grading calculation method of seismic reliability is studied. A bottom frame structure case is analyzed to illustrate that this method is helpful in get- ting the refinement in seismic reliability analysis. It overcomes the unitary limitation on structural damage judgment from the first-excursion mechanics in traditional reliability calculation. This method is suitable for the multi-level risk quantitative analysis of the composite structure.