煤层开采后顶底板的破坏规律及水害防治

Law behind roof and floor failure after coal seam mining and prevention and control of water

针对煤层开采后所面临的顶底板不同充水水源的水害威胁问题,利用FLAC3D数值模拟和冲洗液消耗量、钻孔窥视、压水试验、联合放水试验等多种测试方法,研究堡子煤矿9号煤层回采工作面顶板导水裂隙带和底板破坏带的发育规律、矿井充水水害类型及专项防治水措施。结果表明:9号煤层顶板导水裂隙带发育高度最大为64.26 m,破坏形态似“马鞍状”,底板采动破坏带发育深度最大为12.50 m,破坏形态似“倒马鞍状”;结合含水层赋存层位,煤层开采后顶板主要水害类型为2号煤层采空区积水水害和太原组K2灰岩水害,底板主要水害类型为奥陶系灰岩水害,采取超前疏放和疏水降压措施,可以实现矿井安全开采。

This paper aims to address the water hazard threats posed by different water flooding occurring in roof and floor after coal mining.The study involves investigating the development regularity behind roof water flowing fractured zone and coal seam floor failure zone,types of mine water flooding and special water prevention measures in the No.9 coal seam working face,using FLAC3D numerical simulation,flushing fluid consumption,borehole peeping,water pressure test,joint drainage test and other test methods.The results show that the water flowing fractured zone in the roof of No.9 coal seam has the maximum development height of 64.26 m and the failure mode shaped like a“saddle”and the coal seam floor mining failure zone has a maximum development depth of 12.50 m and the failure mode shaped like an“inverted saddle”;combined with the occurrence horizon of aquifer,the main types of water damage on the roof after coal seam mining are water accumulation damage in No.2 coal mined-out area and K2 limestone in Taiyuan Formation,and floor water disaster is of the main type of ordovician limestone water disaster;and the measures of advance drainage and drainage and depressurization could enable the safe mining of the coal mines.