沥青混凝土心墙堆石坝动力有限元分析

Finite element analysis of dynamic on rockfill dam with asphaltic concrete core wall

采用三维非线性有限元技术,结合某沥青混凝土心墙坝工程,在静力分析的基础上对大坝的动力特性及抗震安全性进行动力反应分析,动力计算中坝体材料及沥青混凝土均采用等效非线性粘弹性模型,计算分析了坝体的加速度反应、动位移反应、大坝的地震永久变形、坝体单元的安全系数的分布规律。结果表明:大坝在地震作用下的动力反应发生了明显的变化;坝体顶部发生了较明显的永久变形,地震最大沉陷量为429mm,为坝高的0.42%;大坝的抗震安全系数基本均大于1,坝体的局部抗震安全性基本满足要求,因此坝体在设计地震作用下是满足稳定要求的。

A three-dimensional finite element model on rockfill dam with asphaltic concrete core wall is established by the three-dimensional and non-linear finite element techniques. Based on static analysis, the dynamic characteristics and seismic safety of dams are analyzed. In dynamic calculation, equivalent nonlinear viscoelastic model is used for dam materials and asphalt concrete. The acceleration response, dynamic displacement response, earthquake permanent deformation and the safety coefficient of the dam element are obtained. Results obtained show that the dynamic responses of dam under the action of earthquake has changed remarkably, an obvious permanent deformation takes place at the dam crest with a biggest subsidence of 499 mm, which is 0.42% of the maximum dam height, and the seismic safety coefficient of dam are almost greater than 1. The local seismic safety of the dam basically meets the practical requirements, so the design of the dam under earthquake is safety.