高烈度区输水泵站地下结构地震易损性分析

SEISMIC FRAGILITY ANALYSIS OF UNDERGROUND STRUCTURE FOR WATER DIVERSION PUMPING STATION IN HIGH INTENSITY AREA

为开展某输水泵站地下钢筋混凝土结构的地震易损性评估,文中采用钢筋混凝土纤维模型和土体弹塑性本构关系,建立了输水泵站地下钢筋混凝土结构的非线性有限元模型。应用增量动力分析方法,按一定比例调整地震动加速度峰值,计算了地下结构在不同强度地震动作用下的弹塑性动力反应。以最大层间位移角和最大抗剪承载力比作为结构的两个性能指标,通过响应面法构建了地下结构在极限状态下的响应面。采用验算点法、均值一次二阶矩法和蒙特卡罗法,计算了地下结构在不同强度地震动作用下的条件失效概率,确定了地下结构的易损性曲线,并对其进行了地震易损性评估。

In order to evaluate the seismic vulnerability of the underground reinforced concrete structure of a water diversion pumping station,a nonlinear finite element model of the underground reinforced concrete structure of a water diversion pumping station is established by using the reinforced concrete fiber model and soil elastic-plastic con⁃stitutive relationship.Using the incremental dynamic analysis method,the peak ground acceleration is adjusted according to a certain proportion,and the elastoplastic dynamic response of the underground structure under different intensity ground motions is calculated.Taking the maximum inter-story displacement angle and the maximum shear capacity ratio as the two performance indexes of the structure,the limit state response surfaces of the underground structure are established by the response surface method.The conditional failure probabilities of the underground structure under different intensity ground motions are calculated by using the checking point method,the mean value first-order second-moment method,and the Monte Carlo method of reliability analysis.The fragility curves of the underground structure are determined,and its seismic fragility is evaluated.