不同边界条件下抽水蓄能电站地下厂房地震动响应分析

随着抽水蓄能电站运行水头和转速的不断提高,边界条件对厂房结构震动影响问题日益突出。为此,以某抽水蓄能电站地下厂房为例,通过建立其有限元三维模型,利用振型分解反应谱分析方法分析了不同边界条件下厂房的抗震性能,研究了地震情况下四种不同边界条件下厂房主要结构的反应特性。结果表明,是否考虑围岩对地下厂房稳定性并无很大影响,顺河向地震荷载对厂房作用影响很小;考虑粘弹性边界条件对顺河向地震波有一定放大作用,不可忽略,而叠加后的总位移值相对无质量边界条件有一定比例下降,下部结构有一定比例上升。研究结果为厂房抗震结构设计与安全分析提供了依据。

Seismic Response Analysis of Pumped Storage Plant Underground Powerhouse Based on Different Boundary Conditions

With the increasing of operation head and rotating speed of the pumped storage power station, the influence of boundary condition on the vibration of powerhouse structure becomes increasingly prominent. Therefore, taking underground powerhouse of a pumped-storage power station as an example, a three-dimensional model was established and the mode-superposition response spectrum analysis method was used to analyze the seismic performance of the powerhouse under different boundary conditions. The response characteristics of the main powerhouse structures of the four different boundary conditions under earthquake conditions were analyzed. The results show that whether or not considering surrounding rock does not have a great influence on the stability of the underground powerhouse. The downstream directional seismic load has little impact on the powerhouse. Considering the viscous-spring boundary conditions has a certain amplification effect on the downstream directional seismic waves and it can not be ignored. However, the total displacement after the superposition of the viscous-spring boundary condition is smaller than the non-mass boundary condition, but it is larger on the substructure. The research provide scientific basis for the powerhouse''s anti-earthquake design and safety analysis.