薄基岩突水威胁煤层开采覆岩变形破坏演化规律研究

针对赵固一矿11011工作面大埋深薄基岩厚覆盖层下煤层开采难度大,存在涌水涌砂威胁的现状,采用现场调研与统计分析方法,论述了薄基岩突水威胁煤层涌水涌砂的条件.其基本顶关键层周期性破断后形成“砌体梁”结构.此文利用“短砌体梁”及失稳后呈“台阶岩梁”的理论解析验算后认为,该面顶板结构极易产生回转及滑落失稳,进而形成突水通道.在此基础上还采用相似模拟试验的方法,分析了采场上覆岩层破坏、运移演化规律,确定了该面项板垮落带高约17m,导水垮裂带高约48 m,故若在此范围内存在含水层或流砂层,应及时采取措施.课题组还用实测法验证了工作面采后覆岩破坏高度,并制订了预防顶板突水开采方案,为类似条件下煤矿防治顶板突水安全开采提供参考.

The Study on the Deformation Process of Overlying Strata in the Deep and Thin Bedrock

According to the geological condition of buried deep with thin bedrock coal seam in the 11011 working face of Zhao-Gu No.1 coal mine,the paper discussed the conditions of thin bedrock water gushing and running sand coal seam by using the coal mine field investigating and statistical analysis method.After analyzing and calculating the working face roof’s structure instability mode by using the theories of ’masonry beam’ and ’step beam’ we have analyzed the overlying strata damage,migration evolution rule of fractures.The results show that and the height of the working face roof water fracture zones is about 48 m.Therefore,some preventive suggestions and measures have to been taken into practice when mining a coal within such a range.The measures can also guide other coal mines with similar geological condition.