基于地震动参数的RC框架结构易损性分析

Seismic Vulnerability Analysis of Reinforced Concrete Frame Structures Based on Ground Motion Parameters

以某典型的12层钢筋混凝土框架结构作为研究对象,研究基于非线性动力时程分析和地震动参数的RC框架结构易损性分析方法。首先采用静力pushover分析判定结构薄弱层,并确定结构性能(capacity)参数;然后应用非线性动力时程分析估计结构地震反应,研究以峰值加速度和基本周期加速度反应谱作为地震动参数结构反应的不确定性,并进一步分析结构地震需求(demand)参数与地震动参数的关系;在此基础上,分别建立该结构基于峰值加速度和加速度反应谱的易损性曲线,通过考虑场地条件对地震动特性的影响,研究场地条件对结构易损性的影响,结果表明不同场地条件下的结构易损性曲线有一定差异。应用本文方法,根据新一代地震区划图或地震安全性评价确定的地震动参数,可以直接估计结构在未来地震中出现不同破坏的概率,这在结构的抗震性能评估和地震损失预测中有一定意义。

In this study, we performed the seismic vulnerability analysis of reinforced concrete （RC） frame buildings based on nonlinear dynamic time history analysis and ground motion pa- rameters.We used a typical 12-story RC frame structure as the research object.First,we conducted static pushover analysis to identify a weak layer and to determine the capacity parameters of the building.Then, we performed nonlinear dynamic time history analysis to estimate the seismic re- sponse of the structure and to analyze the relation between the demand and ground motion param- eters.With respect to ground motion parameters,we studied the uncertainty of the structural re- sponse and then established peak ground acceleration and vulnerability curves based on the first- mode acceleration response spectrum.By considering the impacts of site conditions on ground mo- tion characteristics, we examined the impact of site conditions on vulnerability.The results show differences in vulnerability curves under different site conditions.Based on ground motion parame- ters obtained from new-generation seismic zoning maps or seismic safety evaluations, the pro- posed method can be used to directly estimate damage to a structure following an earthquake,which has significance in seismic performance evaluations and in the prediction of earthquake losses.