强震作用下高拱坝损伤开裂研究

Study of damage and cracking in high arch dam subjected to strong earthquake

本文基于混凝土的力学特性,建立能够反映混凝土动态情况的多轴损伤开裂模型。以等效三维一致粘弹性边界反映远域地基辐射阻尼效应,采用Mohr-Coulomb材料模型模拟坝基裂隙岩体在地震作用下的力学行为,运用非线性地震波动分析方法研究国内某拱坝在强震作用下的损伤开裂过程。通过对大坝的损伤程度以及坝体上、下游面的最大拉应力进行分析,给出大坝的抗震薄弱部位,并对其抗震安全性进行了评价。研究揭示拱坝动力损伤灾变机理,为高拱坝抗震安全评价提供一种分析途径。

A multi-axial damage and cracking model is developed to model the dynamic properties of concrete materials.In this model,Mohr-Coulomb model is used to simulate the dynamic behaviors of dam foundation rock mass under earthquake,with the effect of far-domain radiation damping modeled by a 3D consistent equivalent viscous-spring boundary.This model is applied to an arch dam subjected to strong earthquake,and its damage and cracking process are studied with a method of nonlinear seismic wave motion analysis.Through an analysis on damage extent and maximum tensile stress on its upstream and downstream surfaces,aseismic safety of the dam is evaluated,and the weak parts of the dam in terms of aseismic behaviors are determined.This study reveals a mechanism of dynamic damage and catastrophe,and would provide an analytical approach to aseismic safety analysis of high arch dam.