水电站地下厂房对洞室围岩地震反应的影响

Influences of Underground Powerhouse on Seismic Responses of Surrounding Rock of Cavern

结合某抽水蓄能电站地下厂房工程,建立全机组段地下厂房与洞室群的耦合地震反应时域数值仿真模型,考虑初始地应力、分部开挖与柔性支护以及岩体的材料弹塑性,分析了厂房混凝土结构的存在对洞室围岩的地震位移、速度、加速度、塑性区等反应特征的影响。结果表明,厂房混凝土结构与围岩的相互作用对洞室围岩的地震反应影响不大,对围岩塑性区的发展起到了一定的约束作用,有利于洞室的安全。

A numerical simulation model for analyzing the seismic responses of underground caverns and powerhouse in time domain is firstly established based on a pumped-storage power station project. By taking into account of the initial ground stress, step excavation, flexible support and the nonlinearity of rock mass material in model, the influences of powerhouse concrete structure on the displacement, velocity, acceleration and plastic zone of underground cavern under earthquake are analyzed. The results show that the influence of powerhouse-rock mass interaction on seismic responses of surrounding rock mass is small, and the existence of powerhouse concrete structure may effectively restrain the development of plastic zone of surrounding rock mass which is advantageous to the safety of powerhouse cavern.