拱坝–坝肩三维可变形离散元整体稳定分析  

ANALYSIS OF ARCH DAM-ABUTMENT STABILITY BY 3D DEFORMABLE DISTINCT ELEMENTS

作　　者：张冲[1] 侯艳丽[1] 金峰[1] 王光纶[1] 张楚汉[1] 

机构地区：[1]清华大学水利水电工程系,北京100084

出　　处：《岩石力学与工程学报》2006年第6期1226-1232,共7页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家自然科学基金资助项目(90510018)

摘　　要：三维可变形离散元是模拟不连续介质力学行为的有效数值分析方法。由于该方法采用显式差分方法和自动接触检索技术,故尤其适合于求解弹塑性、大变形和动力问题。首先介绍三维可变形离散元的基本原理及特点,然后对拱坝–坝肩系统整体抗滑稳定进行超载仿真分析和强度折减仿真分析。分析结果表明:超载计算时,拱坝坝肩失稳可能性很小,但是,当水压超载到3.5～4.0倍时,坝体材料会出现较大范围的受压屈服;强度折减计算时,当结构面强度折减3.5倍时,拱坝左坝肩在水压和渗压的作用下开始向下游坍塌,并最终导致拱坝失去支撑而溃决。3D deformable distinct element method （3D DEM） is an efficient numerical method for simulation of mechanical behaviors of discontinuous media. It is especially suitable for analyzing problems of nonlinear, large deformation and dynamic systems due to the explicit finite-difference scheme and the automatic contact detection skill. Herein, the principles and features of the 3D deformable distinct element method are first summarized. Then, an analysis of stability against sliding of an arch dam-abutment system is performed by 3D DEM. Two methods, i.e. overloading method and strength reduction method are used to determine the safety factor against sliding of the system. Some conclusions are drawn as follows： （1） the rock abutment will not slide under even large overloads due to self-locking effect for this specific case, but the dam concrete will yield to compression failure at the overload factor of 4.01 （2） the strength reduction method shows that the left abutment rock reaches failure, which causes the dam collapse under the designed upstream water and seepage pressure when the coefficient of reduction arrives at 3.5. Based on the explicit finite-difference scheme of the 3DEC, the dam collapse process is emulated very well.

关 键 词：岩石力学 三维可变形离散元 抗滑稳定 溃坝 

分 类 号：TU45[建筑科学—岩土工程]