铜川矿务局北区—焦坪矿区，地处陕北黄土高原南缘，地势西北高而东南低，为低中山地貌单元。同时，该区黄土覆盖层厚度较小。矿区有玉华、下石节、陈家山三个矿，煤炭资源丰富。主采4-2#煤层，煤厚8～20m之间，采深为450～500m不等。开采方法以走向长壁放顶煤为主，煤层顶板实行全部跨落法管理模式。在地下采煤的影响下，边坡发生变形与失稳活动，且频频发生。这不仅给矿山人民生命财产带来严重危害，而且严重制约矿山的正常发展。所以，对采煤引起边坡的变形进行研究具有现实意义。 本文结合铜川矿务局“焦坪矿区综放开采岩层与地表移动规律研究”项目，以玉华矿和下石节矿为主要研究对象。首先对矿区边坡的工程地质条件进行了调查。在此基础上，运用FLAC软件，对1407工作面（玉华矿）和211工作面（下石节矿）的采场边坡的变形情况进行模拟。在模拟过程中，考虑了岩石类型、坡体形态、煤层覆存条件、工作面与坡体的相对位置、工作面推进方向、开采速度、采场来压等因素对坡体的影响。再者，运用模拟结果和现场地表移动观测数据、覆岩破坏钻孔探测数据，从基础理论和实践两个方面，确定影响该区边坡变形的因素及引起边坡变形的机理。最后，利用前面两个边坡的岩体力学参数，建立模拟模型对未采区的边坡变形进行预测。 通过以上理论分析和数值模拟，得出该区采煤边坡变形方式为：以座落滑移变形为主，因受岩性的影响有的坡体出现错落滑移变形。

Jiao Ping diggings，north of Tong Chuan mining bureau, lies in a mountainous area in south of loessial altiplano in Shanbei. The topography in northwest is high but the southeast topography is low. This area thickness of loess is thin. It has three diggings: yuhua、xiashijie、chenjiashan and the coal resource is rich. The 4-2# coal bed is picked which is 8 ~ 20m thickness. The coal average deep is 450 ~ 500m. The method of mining coal is along the long wall to pick coal, and the coal top falls freely. Under the underground mining coal influence, the transfiguration and unsteadiness of slope have occured frequently. These movements have not only brought serious harm for the life and property of mine people, also seriously restricted mine normal development. So the research of mined slope has practical significance. Based on the project of “The rock layer and the surface migration rule of Tong Chuan diggings”, this article regards yuhua and xiashijie as research objects. First, it has carried on the investigation to the engineering geology condition of slope in mining area. And it has simulated the deformation of 1407 working surface (yuhua) and 211 working surface (xiashijie) by software FLAC. In the simulation process, it has considered these factors: the rock type, the slope shape, the coal bed condition, the relative position of working surface and the slope body, the working surface advancement direction, the mining speed, the press of rock. Second, using the analogue result and the spot observation data of surface migration, the drill hole survey data of rock destruction, it has determined infective factors and deformation mechanism from theory and practice. Finally, using the front rock mechanics parameters of two slopes, it has established the analog modeling to forecast the distortion of slope in area which has not excavated coal. Through above theoretical analysis and numerical simulation, it has obtained excavated slope distortion way of this area: the slope primary distortion is sitting and slippage, and the slope has occurred occasionally deformation of anomaly and slippage because of different lithology.