厚黄土覆盖层下覆岩采动裂缝闭合特征及应用研究

Studying on Mining Cracks Closure Characters of Overburden under Thickly Loess Layer and It's Application

为科学评价老采空区作为新村址的地基稳定性,采用钻孔冲洗液漏失量观测、彩色钻孔电视观测、理论计算方法对厚黄土覆盖层条件下煤层开采16a后覆岩采动裂缝闭合特征进行研究。结果表明:经过多年移动变形,采空区上覆岩层中未发现离层、空洞,采动裂缝已基本闭合,工作面煤柱上方未发现明显裂缝,隔离煤柱有效控制了覆岩裂缝发育。采动裂缝宽度与采空区距离呈现远小近大的特征,距离采空区较近的覆岩裂缝宽度相对较大,距离采空区较远的覆岩裂缝已基本完全闭合,导水裂缝带高度最大减少了21%。分析认为,建筑物附加载荷对老采空区的扰动、残留空隙二次压缩和地表残余变形对新村址影响较小,地基具有较好的稳定性。

In order to scientific evaluated base stability that old goaf to new village site,and then the mining cracks closure characters after coal mining 16 a under thickly loess overburden layer were studied by the following methods,which included that drilling fluid leakage observation,colourful TV observation and theoretical calculation method and so on,the results showed that after many years movement and deformation,separation,cavity were not found in overburden above goaf area,and mining fractures already closure,and also obviously fractures were not found above working face pillar,overburden fractures development was controlled effectively by isolation coal pillar,the characters of mining crack width and goaf distance appeared as far small and near large,overburden crack width was large as the distance to goaf was small,and overburden cracks already closure as the distance to goaf was large,and water conducted zone decreased about 21%,the influence that buildings additional load to old goaf distribution,the second compress of residual interspace and surface residual deformation to new village site all small,and the base also stability.