考虑应变速率影响的混凝土重力坝非线性地震响应分析

通过引入应变速率、损伤变量以及刚度退化指标等参数,建立了应变率相关的混凝土弹塑性损伤模型。运用该模型对某重力坝厂房坝段分别就率相关及率无关两种情况进行了三维非线性地震响应时程分析。深入研究了混凝土应变速率等相关特性对结构动力响应的影响。结果表明,应变速率对混凝土的力学性能有一定的影响,随着应变速率的增加,坝体结构的变形减小,主拉应力有所提高,应变能有所减小以及开裂损伤有一定的降低。所得结论对混凝土重力坝的震害研究有一定的参考价值。

Nonlinear Seismic Responses Analysis of Gravity Dam Considering Strain Rate Effect

In this paper,a new rate-dependent concrete elasto-plastic damage model for simulating the mechanical behaviors of concrete is established by introducing the effect of strain rate,damage variable and stiffness degradation variables.A series of response history analyses on three-dimensional nonlinear seismic response of the gravity dam are carried out by employing this model considering the effect of strain rate or not.It is found that the strain rate caused by seismic loading varies significantly and affects the dynamic response.Results show that displacement,strain energy and damage obviously reduce with increase of strain rate,while tensile stress has a little increase.The conclusions are valuable for the earthquake analysis of the gravity dams.