西藏某高陡露采边坡稳定性分析与优化

Stability Analysis and Optimization of a High and Steep Open-pit Slope in Tibet

为探讨西藏某高陡露采边坡稳定性,利用数值模拟和极限平衡法对西藏某露天矿高陡边坡稳定性进行评价,并考虑暴雨荷载劣化因素,采用FLAC3D边坡稳定性进行定性计算,并对露采边坡不同开采方案进行对比分析,选定最佳设计方案后,利用slide选择最终露采边坡角。结果表明原设计方案安全平台15 m,清扫平台15 m,接渣平台20 m;岩质台阶坡面角75°,碎石土覆盖层坡面角75°虽能保持边坡整体稳定,但碎石土区边坡欠稳定,且剥采量较大;建议修改方案为安全平台6 m,清扫平台12 m,接渣平台30 m;岩质台阶坡面角70°,碎石土覆盖层坡面角40°,一期最终边坡角38°,能使碎石土区域边坡及整体边坡保持稳定,且能减少剥离量,在保证安全的情况下能实现效益的最大化;最终露采边坡角为38°,此时边坡稳定性可满足自然开挖和暴雨载荷下的边坡稳定性要求。

The stability of a high-steep slope of an open pit mine in Tibet is evaluated by numerical simulation and limit equilibrium method.Considering the deterioration of rainstorm load,the FLAC3D is used to qualitatively calculate the slope stability,and different mining schemes of open-pit slope are compared and analyzed.After choosing the best design scheme,the slide is used to select the final open-pit slope angle.The results show that the original design scheme with a safety platform of 15 m,a cleaning platform of 15 m,a slag platform of 20 m,a rock step slope angle of 75°,and a gravel soil cover slope angle of 40°,that can maintain the overall stability of the slope,but the slope in gravel soil area is not stable and the stripping volume is large.It is suggested that the modification scheme should be a safety platform of 6 m,a cleaning platform of 12 m,a slag platform of 30 m,a rock step slope angle of 70°and a gravel soil cover slope.The surface angle is 40°and the final slope angle is 38°in the first stage,which can keep the stability of the gravel soil slope and the whole slope,reduce the amount of stripping,and maximize the benefit under the condition of ensuring safety;Finally,the slope angle of open-pit mining is 38°.At this time,the stability of slope can meet the requirements of slope stability under natural excavation and rainstorm load.