水体对河床式水电站厂房动力特性和地震动力响应的影响分析

为探讨库水、尾水及流道内水体对河床式水电站厂房动力特性和地震动力响应的影响,以势流体单元模拟水体、粘弹性边界模拟地基辐射阻尼效应,建立了完整的机组坝段厂房结构—地基—水体耦合有限元分析模型。结果表明:水体对河床式厂房结构动力特性和地震动力响应有较大的影响,没有正确考虑水体作用的动力计算偏于不利;仅模拟库水和尾水的附加质量及势流体模型,由于对占主要部分的流道内水体的影响无法估计而带来较大的误差;计算中对水体进行简化模拟时必须考虑流道内水体的作用。

Effects of water body on dynamic characteristics and seismic responses of run-of-river hydropower house

A complete plant structure-foundation-water body coupling FEM model have been developed to study the effects of water bodies in the flow passages and reservoir on the dynamic characteristics and seismic responses of a run-of-river hydropower house. This model adopts potential-flow fluid elements to simulate these water bodies, and a viscous-spring boundary for considering the radiation damping of the foundation. The results show that the water bodies have a significant effect on the vibration frequencies and seismic responses of the powerhouse and that neglecting the effects of water body may be unfavorable to the structural design of powerhouse. Simulation errors could be produced by simplification in those methods that simulate the water body in the reservoir only, such as the added mass model or potential fluid model, because the water bodies in the flow passages have a significant effect. Thus, the effect of water bodies in the flow passages must be considered for more accurate simulations.