露天矿边坡岩体稳定性各向异性分析方法及工程应用

露天矿边坡岩体通常含有大量IV、V级结构面,影响岩体稳定性。针对这种岩体特性,提出了系统的工程分析方法：首先,应用3GSM非接触测量系统对岩体出露结构面现场测试,统计结构面几何参数概率模型;进一步根据Monte Carlo方法生成裂隙网络,分别利用离散介质渗流方法和几何损伤理论,在分析REV尺寸效应基础上,计算岩体渗透张量和弹性张量,实现岩体参数表征;最后,基于等效连续介质模型,建立各向异性岩体渗流应力耦合模型,采用COMSOL有限元软件分析边坡岩体稳定性。应用该方法对抚顺西露天矿南帮进行了实例分析,计算结果与实际吻合较好。提出的露天矿边坡岩体稳定性分析方法能够考虑节理分布导致的岩体各向异性特征,简单合理,具有良好的工程应用前景。

Anisotropy analysis method for stability of open-pit slope rock mass and its application

A lot of grade IV and V discontinuities distributed in the open-pit slope rock mass have great effect on the stability of rock mass. According to the characteristics of open-pit slope rock mass, a systematic analysis method is put forward. Firstly, a 3GSM contact-free measuring system is employed to capture the discontinuities outcropped in rock mass, and the probability model for geometric parameters of structural plane can be obtained. Then the fracture network is generated by means of the Monte Carlo method. Considering the size effects of REV, the permeability tensor of rock mass is calculated using the discrete medium seepage method, and the elasticity tensor of rock mass is obtained using the geometrical damage theory, and the rock mass parameters are finally determined. Finally, the anisotropic seepage-stress coupling model based on the equivalent continuum model is established for mechanical analysis of stability of slope rock mass by using COMSOL software. Moreover, the proposed method is applied in the southern slope of Fushun west open-pit mine, and the results agree with the failure observation well. The stability of slope rock mass can be evaluated by using the proposed method considering the characteristics of rock mass caused by distribution of joints. It is simple but very reasonable, and hence it has a good application prospect.