软弱基底排土场堆载过程中稳定性数值模拟

Numerical Simulation of Stability in Loading Dump with Weak Basement

针对软弱基底排土场普遍存在稳定性差的问题,在分析了排土场失稳的主要影响因素以及常见的5种失稳模式的基础上,结合胜利东二露天煤矿南排土场南帮边坡工程地质实际,基于强度折减理论,运用大型岩土数值模拟软件FLAC3D对排土场逐水平堆载过程中基底与边坡岩体变形破坏规律及稳定性进行了数值模拟分析,确定了南排土场南帮边坡的破坏模式以及最终排弃高度。结果表明:胜利东二露天矿南排土场边坡变形破坏主要受排弃物料重力影响,随着排弃高度的增加,基底内部第四系弱层最大位移呈线性增加,弱层以下岩土体变形量较小,其滑坡模式为沿基底内部弱层发生的剪切圆弧滑动,可在原设计基础之上继续排弃一个排土台阶高度,提高了排土场的空间利用率,并为类似排土场边坡设计提供借鉴。

Aiming at the widespread problem of poor stability about dump with weak basement,based on the analysis of the instability of the main influence factors and five kinds of common instability mode about the dump,combined with the engineering geological practice of south slope in south dump of Shengli eastern NO.2 surface mine,based on the strength reduction theory,the deformation-failure rule and stability of basement and slope rock mass in loading dump were analyzed by large geotechnical numerical simulation with FLAC^3 D.The landslide model and the final dumping height in south slope of south dump were researched.The research results show that the deformation-failure is mainly influenced by the gravity of the dump,and the maximal displacement of the basic weak layer increases linearly with the increase of the dumping height and the deformation under the weak layer of the rock mass is small.The landslide model is shear circular sliding along the basic weak layer and it can add one dump bench on the original design in the south dump of Shengli eastern NO.2 surface mine.It improves the utilization of dump space and provides reference for the similar dump slope designing.