表土层厚度对地面瓦斯钻孔稳定性影响研究  

On impact of thickness of topsoil on stability of ground gas drilling

作　　者：赵国贞[1,2] 马占国[1,2] 龚鹏[1,2] 王坤[2] 蒋众喜[2] 

机构地区：[1]中国矿业大学深部岩土力学与地下工程国家重点实验室,江苏省徐州市221116 [2]中国矿业大学力学与建筑工程学院,江苏省徐州市221116

出　　处：《中国煤炭》2013年第10期35-40,共6页China Coal

基　　金：国家自然科学基金项目(51074163);国家自然科学基金重点项目(50834005);江苏省自然科学基金(BK2009092);中央高校基本科研业务费专项资金资助(2012LWB66);江苏省研究生培养创新工程(CXZZ12_0923)

摘　　要：针对淮南矿区煤矿11-2煤层覆岩物理力学特性,利用ANSYS软件中死活单元技术与材料非线性分析方法,模拟在不同表土层厚度下覆岩的水平变形情况,研究表土层厚度对瓦斯抽采钻孔稳定性的影响。研究结果表明,不同表土层厚度下,覆岩水平变形"O"形圈现象明显,并表现出明显的对称性,Ⅰ测线和Ⅲ测线变形错动明显,呈现趋势对称,梯度差值不对称;Ⅱ测线表土层变形平缓;随表土层厚度增加,覆岩水平位移最大变形位置明显由地表、表土层底部向表土层下部基岩转移,基岩梯度变化区间个数明显减少,梯度差值增大;工作面中部Ⅱ测线位置不容易剪断,但中部的破碎岩体易被压实,后期抽气效率不高。Based on the physical and mechanical properties of overlying strata of 11--2 coal seam located in Huainan mining area, the paper researches the impact of the thickness of topsoil on stability of gas drainage boreholes. It uses the birth-death element technology of ANSYS soft- ware and the material nonlinear analysis methods to simulate the horizontal deformation of over-lying strata with different thickness of topsoil. The results show that O-ring phenomenon of overlying strata is obvious and the horizontal deformation presents obvious symmetry with different thickness of topsoil; I and III survey lines show the tendency symmetry and gradient difference asymmetry with evident dislocation deformation; however, deformation of topsoil of II survey line is gentle; with the increases of topsoil thickness, the maximum horizontal displacement deformation position of overlying strata transfers to the bedrock from the surface and the bottom of topsoil, and the number of gradient interval significantly decreases and gradient difference increases, the position of II survey line in middle part of working face is not easy to cut, but the broken rock is easily compacted, so the gas post-extraction is not efficient.

关 键 词：瓦斯抽采 表土层厚度 覆岩 水平位移 数值模拟 死活单元 

分 类 号：TD325[矿业工程—矿井建设] TD712