基于联合有限元-离散元的混凝土重力坝破坏三维仿真模拟

水利工程中混凝土重力坝在地震等作用下的三维破坏形式以及破坏过程对大坝安全影响重大。本文建立了固体材料的联合有限元-离散元(Combined Finite-Discrete Element)三维数学模型,并引入Single/Smeared断裂损伤模型,模拟混凝土材料的破坏。数学模型经验证后,用于地震作用下混凝土重力坝破坏的三维数值模拟,结果表明,联合有限元-离散元方法能够有效模拟坝体的破坏模式和破坏阈值条件,且具有将坝体连续变形与不连续断裂有机结合的优点。通过一系列数值模拟工况的对比,分析了模型网格分辨率对破坏条件、破坏模式以及程序计算效率的影响,研究结果能够为大坝的抗震设计提供有价值的参考。

Three-dimensional simulation of failure of a concrete gravity dam using the Combined Finite-Discrete Element Method

The three-dimensional failure pattern and failure process of concrete gravity dams under the action of earthquakes have great influences on safety of dams in hydraulic engineering.A three-dimensional mathematical model based on the Combined Finite-Discrete Element Method (FDEM) was established for solid materials.The Single/Smeared model was introduced into the FDEM model as the damage constitutive law of concrete material.After verification,the mathematical model was used to simulate the three-dimensional failure of a concrete gravity dam under earthquakes.Numerical simulation results show that the FDEM model is capable of effective reproduction of both the failure pattern and the failure threshold conditions of concrete dam.It has the advantage of well combination of the continuous deformation and discontinuous rupture in the simulation.A series of numerical simulations were carried out for different cases,based on which,the mesh resolution''s influence on the failure threshold,failure pattern and computational efficiency was investigated.The research achievements can provide valuable references for the earthquake-proofing design of large dams.