考虑损伤的结构抗震可恢复性

STRUCTURAL SEISMIC RESILIENCE CONSIDERING DAMAGE

在定义结构剩余抗震能力比、结构整体抗震可恢复性指标以及对应于建议损伤区间的局部抗震可恢复性指标的基础上,考虑建筑物不同重要性和不同破坏影响,建议了不同的结构抗震可恢复性等级和相应的整体可恢复性指标变化范围,以及局部抗震可恢复性指标的下限值。结合易损性分析得到特定地震强度下得到其剩余抗震能力比的期望值。根据损伤区间规划、损伤性能目标以及各可恢复性等级结构剩余抗震能力比曲线下包络线,建议了结构抗震可恢复性概念设计框架。这种概念设计框架是在描述结构损伤程度的基础上,能够更加直接地评估结构面临受损或序列型强震时其剩余强度储备的情况。针对算例情况而言,按照现行规范设计的结构其抗震可恢复性和倒塌概率均满足要求,大震作用下结构剩余抗震能力比的期望值与最大结构层间位移有较好的对应关系,说明结构抗震可恢复性评估方法与常规设计方法之间的关联。

Based on the residual seismic capacity ratio, the global structural seismic resilience index and local seismic resilience indexes for damage regions, the ranges of global seismic resilience index and the lower limits of local seismic resilience indexes for different seismic resilience levels are suggested, taking into consideration the importance and social impacts of buildings of concern. Fragility analysis is applied to achieve the expectation of residual seismic capacity ratio of structures subject to certain levels of earthquakes. A conceptual design framework of structural seismic resilience is developed based on the combination of damage regions, damage performance objectives and the lower envelops of residual seismic capacity ratio curves of structures with different seismic resilience levels. The conceptual design framework is solidly based on the description of damage status of structures. Thus, it can be more directly utilized to evaluate residual seismic resistance of structures experiencing damage or sequence-type strong earthquakes. The results from the case study indicate that the example frame designed in accordance with the current seismic code is also satisfactory from the standpoint of seismic resilience and collapse probability. There is a good correlation between the expectation of residual seismic capacity ratios of structures under rare earthquakes and the maximum story drift, showing correspondence between the resilience-based assessment method and the conventional seismic design method.