贵州水城煤矿上覆岩层破坏机理及地质环境灾害预测

Overlying Strata Failure Mechanism and Geological Environment Hazard Prediction in Shuicheng Coalmine,Guizhou prediction of a coalmine in Guizhou province

山区煤矿地质构造复杂,采煤导致矿区地表变形形式与平原地区有很大差异。以贵州水城煤矿为例,依照其工程地质条件及开采方式,选取贯穿矿界的3条地质勘探剖面,利用FLAC3D有限差分软件对开采过程进行数值模拟,预测采煤引起上覆岩破坏机理和地表破坏形态。研究结果表明:前期阶段上覆岩层破坏和地表下沉最为明显,随着采区向深层延伸,地形起伏增大,倾斜的覆岩组合特征和岩性发生改变,地表不会形成类似平原地区的沉陷盆地和沉陷漏斗,而是产生大量裂缝;上覆岩层破坏表现为出现贯通的拉张裂隙带,尤其在沟谷等应力集中区域更为明显,将会改变矿区原有水文地质条件,不排除局部地表水出现疏干的状况。最后结合上覆岩层变形量及破坏机理,对采区可能引发的地质环境灾害进行了预测。研究成果对山区煤矿土地复垦和矿山地质环境评价提供了参考。

Geological structures in mountainous area are complex,coal mining caused surface deformation patterns in those areas vary widely with deformation in flat areas. Taking the Shuicheng coalmine in Guizhou as an example,according to its engineering geological condition and recovery method,selected 3 geological sections run through the coalmine carried out numerical simulation of mining process through FLAC3 D finite difference software,predicted overlying strata failure mechanism and surface failure pattern. The result has shown that in the early stage,overlying strata failure and surface subsidence are most visible. Along with the winning district extending deeper,surface change increasing,declining overlying strata combination features and lithology have been changed. Ground surface will not form subsided basins and funnels in a similar way to flat areas,but instead of massive fissures. The failures of overlying strata take the form of thread together extensional fissure zones. Especially in stress concentrated gullies more evident,it will change mine area original hydrogeological condition,does not exclude surface water drained off locally. Finally combined with overlying strata deformation magnitude and failure mechanism carried out prediction of winning district geological environment hazards could have led to. The results have provided reference for mountainous area coalmine land reclamation and geological environment assessment.