高拱坝-地基体系强震破坏机理和整体抗震安全性研究

本文在高拱坝-地基整体抗震安全评价体系的基础上，对设计地震动峰值加速度达0.5565g的大岗山拱坝—地基体系的地震响应进行数值分析，并分别对其在不同地震超载倍数和不同基岩控制性滑裂面抗剪强度降低倍数下的安全性和破坏机理进行研究，进一步明确了以寻求坝体控制性位移或与位移相关的变量随安全系数变化曲线的拐点作为整体失稳判断准则的具体实施方法，对其整体抗震安全性作出评价。研究表明，由此建立的高拱坝-地基体系整体抗震安全评价方法是可行的。

Study on the failure mechanism in earthquake and the seismic safety of integral high arch dam system

In this paper, based on a new seismic safety concept of arch dam a corresponding analytical technique using FEM has been developed. The seismic safety of Da Gang Shan arch dam with a design peak ground acceleration of 0.5575g due to seismic overloading and shear strength reduction of the slide surfaces in the wedges are given respectively. In the numerical model, dam-reservoir-foundation interaction and nonlinear contact between contraction joints, dam-foundation interface as well as slide surfaces in abutment wedges are taken into consideration. Both dam body and critical abutment wedge are treated as an integral system and the system safety are determined by one single safety criteria, defined as the point of inflection of the relationship curve between dam displacement and seismic overloading factor or shear strength reduction factor. By this way, the solution was proved to be practicable.