永陇矿区松软富水顶板灾变机理与防控研究

Research on roof disaster mechanism and prevention under soft water-enriched roof in Yonglong Coalfield

针对黄陇侏罗纪煤田采场出水压架灾害频发的现状,以永陇矿区4个综放工作面为工程背景,围绕松软富水地层覆岩破断与顶板来压特征、离层水致灾机理及灾害预警防控开展了现场跟班实测与理论研究。研究结果表明:覆岩关键层运移破断与采场矿压及离层水害存在因果关系。由于破断步距大、控制岩层组厚度大,复合关键层破断导致采场大周期来压显现异常强烈;所控岩层组断裂下沉后在洛河组含水层底部产生离层空间。受到离层水压和含水层持续补给等双重作用,离层积水越层下泄引发采场出水。基于以上认识,在实践中探索并完善了离层水害防控对策,构建了以"大周期来压、支架阻力高位预警、水位降速、宏观矿压显现异常"为主的出水压架预警机制;建立了以危险区域划分、采放工艺优化及工作面日常管控为主的防控体系。研究成果已成功指导了多个工作面的顶板水害防控,对类似地层条件的矿井具有良好的示范效应。

Supports crushing and water inrush disasters are frequent occurrence at Huanglong Jurassic Coalfield in Northwest China. Taking four fully mechanized working faces as engineering background,this study presents the results of monitoring and theory investigation of overburden breaking,strata movements,roof weighting,water inrush from separated fractured spaces,and finally,puts forward prevention measures for above disasters. The results show that the breaking characteristic of key strata is critical to the roof weighting and separation water disasters. The large breaking span and thickness of compound key strata generally cause large periodical roof weighting followed by abnormal strata behaviors during working face advances,which causes bed separated fractures to be generated under the Luo he Group. Subjected to dual effects of water pressure and continuous recharge from aquifer,water in separation breaks through aquiclude and rushes into working face.Based on above viewpoints,early warning system is established,which consists of large periodical roof weighting,abnormal high level warning of support resistance,rapid decline of water table and abnormal strata behaviors. Furthermore,a prevention system for roof and water disasters is established,which consists of predictions for potential disaster locations,top-coal drawing method optimization,and working face managements. The outcomes have contributed to the prevention of water inrush disasters at several panels. This study provides a new methodology and a set of engineering principles for the coal mines with similar geological conditions.