多煤层开采条件下高陡山体变形控制

Deformation control of high and steep mountain under condition of multi-coal mining

采矿活动诱发高陡山体发生大范围高位远程滑坡,贯穿我国西南矿区规划、开发及闭矿整个阶段,前期规划时矿区采动坡体稳定性控制至关重要。为提高矿区防灾减灾水平,从西南地区地形地质及采矿条件出发,系统归纳了控制高陡山体稳定性致灾因素,提出了适宜于该矿区高陡山体稳定性控制的多煤层协调开采方法,采用离散单元法对山体变形特征及稳定性控制效果进行了模拟分析。研究结果表明:地下开采是坡体变形之诱因,重力场与采动应力场叠加引起应力集中,是引起岩体破裂及坡体失稳之本质。多煤层协调开采,可以将开采活动对覆岩变形及破坏速率降低,逐步释放总变形量,利用地表变形符号的变化,动态调整水平变形及倾斜等坡体稳定性敏感指标,提高采动坡体的稳定性。利用该方法,模拟计算某矿区采动高陡山体最大水平变形降低了67%~85%,最大倾斜值降低了41%~67%,梯子崖(永宁组灰岩)稳定性得到控制。多煤层协调开采技术是解决西南高陡山体下煤炭资源安全高效开采的有效途径。

The prevention and control of massive high-speed and long-distance landslide induced by underground mining will run through the whole stage of planning,development and mine closure in Southwest China.The stability control of mining slope is very important in the early planning stage.In order to improve the level of disaster prevention and reduction in mining areas,based on geology and mining conditions,the disaster factors of controlling the stability of high steep mountains are summarized systematically,a multi seam coordinated mining method suitable for the stability control of high and steep mountains in the mining area is put forward,and the discrete element method to simulate and analyze the deformation characteristics and stability control effect of mountains is used.The results show that underground mining is the main cause of slope deformation,and the superposition of gravity field and mining stress field causes stress concentration,which is the essence of rock fracture and slope instability.Coordinated mining of multiple coal seams can reduce the deformation and failure rate of overburden,gradually release the total deformation,dynamically adjust the sensitive indexes of slope stability,such as horizontal deformation and slope stability,and improve the stability of mining slope.By using this method,the maximum horizontal deformation are reduced by 67%-85%,the maximum inclination are reduced by 41%-67% respectively,and the stability of tiziya(limestone of Yongning formation)is controlled.Multi seam coordinated mining technology is an effective way to solve the problem of safe and efficient mining of coal resources under the high and steep mountain in Southwest China.