库水模型及库水深度对拱坝动力响应的影响

基于接触非线性有限元模型,以锦屏一级拱坝为例,库水分别采用附加质量模型、可压缩流体有限元模型、不可压缩流体有限元模型计算了正常蓄水位及运行低水位时坝体的动力响应,结果表明:库水模型对拱坝动力响应有较大影响,随库水深度的增大,各模型计算结果差异增大;相比于流体可压缩模型,采用不可压缩流体模型所得动力响应普遍偏大;运行低水位工况,由于静水压力减小导致拱效应减弱,从而降低了拱坝的整体性,因此运行低水位工况各缝开度普遍高于正常蓄水位工况,且其拉应力范围较大,因此,运行低水位工况将对抗震设计起控制作用。

Effects of reservoir model and reservoir depth on dynamic responses of arch dams

Based on the contact nonlinear finite element model, the dynamic responses of Jinping arch dam in the case of normal water level and operating low water level were simulated by using additional mass model, compressi-ble fluid finite element model and incompressible fluid finite element model for reservoir respectively. The results show that the effects of reservoir model on dynamic responses of arch dams are notable. The greater the reservoir depth is, the bigger the differences among them will be. Comparing with the compressible fluid finite element model, the incompressible one exaggerates the dynamic response. In the case of operating low water level, the integrity of arch dam is lowered due to the weakened arch effect. The opening width is greater than the case of nor-mal water level. Meanwhile, the range of tensile stress is wide, so the case of operating low water level will control the seismic design.