地震荷载作用下大坝系统的非线性动力损伤分析

Nonlinear dynamic damage analysis of dam and rock foundation under the action of earthquake

本文在连续损伤力学理论基础上,把非线性动力损伤的概念引入岩石类介质的本构模型,分别提出岩石类材料的脆性动力损伤和粘弹塑性动力损伤破坏模型。同时,将损伤、渗流及孔隙率演化等相互耦合的有效应力概念引入Mohr Coulomb破坏准则,用于分析在渗流压力、损伤发展、孔隙率演化和动应力共同作用下堤坝及岩基系统的非线性地震动力损伤,建立了相应的二维有限元动力损伤数值分析模型,并应用于地震荷载作用下的龙滩混凝土重力坝及其岩基的破坏过程分析,分析结果可作为大坝的安全性评估的依据。

Based on the theory of continuous damage mechanics the concept of nonlinear dynamic damage is introduced into the constitutive model for rocky material. The model for brittle material and the model for visco-plastic material are established consequently. Furthermore, the effective stress formed by the combination of damage, seepage pore pressure and porosity evolution in cracked mass are introduced into the Mohr-Couloum failure model to develop the failure criterion for dynamically damaged rock structure. The corresponding 2-D models of FEM for numerical calculation of damage are established. The proposed models are applied to analyze the failure process of the gravity dam and its rocky foundation in the Longtan Project under the action of earthquake.