高海拔地区金属矿排土场稳定性分析及关键参数优化  

Stability Analysis and Key Parameters Optimization of Metal Mine Dump in High Altitude Area

作　　者：张凯 高毓山[3] 刘奎明 陈成诚 陶志刚 苏春阳 Zhang Kai;Gao Yushan;Liu Kuiming;Chen Chengcheng;Tao Zhigang;Su Chunyang(State Key Laboratory for GeoMechanics and Deep Underground Engineering(Beijing),Beijing 100083,China;School of Mechanics and Civil Engineering,China University of Mining and Technology(Beijing),Beijing 100083,China;Nanfen Open-pit Iron Mine,Benxi Iron and Steel Group,Benxi 117000,China;Geological Resources Department of Tibet Huatailong Mining Development Co.,Ltd.,Tibet 850200,China)

机构地区：[1]深部岩土力学与地下工程国家重点实验室(北京),北京100083 [2]中国矿业大学(北京)力学与建筑工程学院,北京100083 [3]本溪钢铁集团南芬露天铁矿,辽宁本溪117000 [4]西藏华泰龙矿业开发有限公司地质资源部,西藏拉萨850200

出　　处：《金属矿山》2020年第3期71-78,共8页Metal Mine

基　　金：山东省自然科学基金项目(编号:017PD011);2019国家级大学生创新创业训练计划项目(编号:c201806121)。

摘　　要：针对高海拔地区金属矿排土场稳定性问题,以西藏甲玛矿区角砾岩排土场边坡为依托,采用FLAC^3D数值模拟软件,基于有限差分法并结合强度折减理论,利用冻融损伤修正后的岩体力学参数,得出了在当前排土工艺下边坡的位移变化规律、应力变化特征、剪应变速率和塑性区的分布特征,分析了其稳定性,并进行了关键参数优化。研究表明:①高海拔这一因素易导致岩体在冻融循环作用下损伤劣化;②滑坡产生的过程可归纳为:当排土场形成之后,坡体内部出现塑性破坏区,伴随着剪应变带逐渐扩大,边坡内的塑性破坏区面积也增加,剪切塑性区将会大面积出现在斜坡的前缘上,其塑性区基本贯通,滑坡产生;③角砾岩排土场边坡在当前排土工艺下有沿着近似圆弧滑面向坡脚滑动的趋势;④确定的最优关键参数为单台阶高度40 m,组合台阶宽度40 m。模拟结果与现场破坏情况具有显著的一致性,且优化后的排土工艺提高了排土场的稳定性,对于类似排土场边坡稳定性研究具有一定的借鉴意义。Aming at the stability of metal mine dump in high altitude area,based on the slope of breccia dump in Jiama Mining Area of Tibet,FLAG^3D numerical simulation software,finite difference method,strength reduction theory and mechanical parameters of rock mass modified by freeze-thaw damage are used to solve the stability problem of metal mine dump in high altitude area.The displacement change rule,stress variation characteristics,shear strain rate and shear strain rate of the slope under the current dumping technology are obtained.The distribution characteristics of plastic zone are analyzed,its stability is analyzed,and the key parameters are optimized.The study results show that:①high altitude is easy to cause damage and deterioration of rock mass under the action of freeze-thaw cycle;②the process of landslide can be described as:after the formation of waste dump,plastic failure area appears inside the slope body,along with the gradual expansion of shear strain zone,the area of plastic failure area in the slope also increases,the shear plastic area will appear on the front edge of the slope in large area,and its plastic area is basically connected,resulting in landslide;③under the current dumping technology,the slope of waste dump tends to slide along the approximate arc sliding surface to the slope toe;④the optimal key parameters are determined as follows:the height of single step is 40 m,and the width of combined step is 40 m.The simulation results are consistent with the site failure,and the optimized dumping technology improves the stability of the waste dump,which has a certain reference significance for the slope stability study of similar waste dump.

关 键 词：金属矿山 高海拔 排土场 稳定性分析 FLAC^3D数值模拟 参数优化 

分 类 号：TD854[矿业工程—金属矿开采]