矿区岩质斜坡稳定性评价与研究

The Evaluation of Mine Rock Slope Stabilities

以某矿为例,采用不平衡推力法和统计矩法等方法对矿区斜坡稳定性进行了评价,给出了各种算法下斜坡的安全系数和可靠指标;同时采用FLAC3D有限差分数值计算方法,对斜坡的位移场、速度场和稳定性做出综合评价,得出了斜坡安全系数;最后运用瑞典法、Bishop法、Janbu法等其他方法也对斜坡的安全系数进行了计算;比较研究结果表明:工程地质环境等随机变量对斜坡稳定性影响较大;FLAC3D与其他方法计算值基本一致,在矿区特殊的地质环境下,统计矩法能够有效地避免不确定因素过多产生的误差,其简便的计算和合理的结果显示了很大的优越性;对斜坡稳定性分析要求严格时,应采用多种方法进行综合比较。

With the economic development, the ecological, geological and environmental problems are becoming an ever increasing concern. The stability of the mining slopes is a very important engineering problem. In this paper, the reliability evaluations are performed on the mine material slopes using conventional force limit equilibrium and point estimate methods in a mine in, Hubei Province. Both the factors of safety and the reliability indices are obtained throughout these analyses. The finite difference numerical analysis models are also established using software FLAC3D. The displacement and the rate of the deformation of the slope are evaluated and the factor of safety is also obtained through the numerical analysis. The factors of safety are also analyzed by different limit equilibrium methods, such as, Swedish, Biship and Janbu methods. The results indicate that the engineering geology environment factors, such as, cohesion, internal friction angle and the unit weight, have large impact on the stability of the slope. The numerical analysis results by FLAC3D are consistent with the other simplified analytical results. Under the special environment of in the mining area, the point estimate method can effectively avoid the errors originated from the uncertainties. The simple analytical approach and reasonable results have a significant advantage over other methods. It is also concluded that, for a complicated slope problem with higher requirement, multiple analyses are desired in order to result in the reliable conclusions.