摘要
井下采空区储水是西部生态脆弱区保水开采的重要手段之一,防水密闭墙的稳定性关系到采空区储水的安全性。针对采空区防水密闭墙稳定性难以监测、抗水压能力难以预测这一关键问题,以察哈素煤矿井下采空区防水密闭墙为背景,采用理论分析、数值模拟和现场实测等方法,测试了煤层及顶底板力学性能,获得了煤体及顶底板最小抗压强度;考虑密闭墙结构的受力特点,计算推导了不受采动影响情况下防水密闭墙的最大承压能力;建立了防水密闭墙数值模型,分析了超前采动影响和不同水头高度(6、9、12、15 m)下密闭的受力状态、变形及破坏情况;研发了井下采空区防水密闭墙应力、位移监测系统,并基于理论分析,合理布设监测点,且在现场进行了应用。在此基础上,结合理论分析与数值模拟结果,确定了防水密闭墙的最大安全水头高度和警戒水位线的水头高度。结果表明:超前采动对防水密闭墙损伤有一定的影响,且水压作用加大了密闭墙与煤柱接触面间裂隙滑移范围;采终防水密闭墙承受的最大水头高度为12 m,防水密闭墙的警戒水位线的水头高度为9.6 m;防水密闭墙在墙体与煤柱的接触面以及密闭墙体顶底角位置为结构弱面,易发生破坏,应注意加强密闭墙相嵌与煤岩体位置以及密闭墙体顶底角位置处的监测或观测,必要时可采用注浆封堵手段对结构弱面或渗漏部位进行加固处理。研究结果可为类似矿井防水密闭墙的稳定性监测与抗水压能力评估提供理论基础与应用参考。
Underground water storage in goaf is one of the important means of water conservation and mining in the western ecologically fragile area.The stability of waterproof sealing wall is related to the safety of water storage in goaf.In view of the key problem that the stability of the waterproof sealing wall in the goaf is difficult to monitor and the water pressure resistance ability is difficult to predict,under the background of underground mining end sealing in Chahasu Coal Mine,by means of theoretical analysis,numerical simulation and field measurement,the mechanical properties of coal seam and roof and floor are tested,and the minimum compressive strength of coal body and roof and floor is obtained.Considering the stress characteristics of the sealing wall structure,the maximum bearing capacity of the waterproof closed wall without the influence of mining is calculated and deduced.The numerical model of waterproof sealing wall is established,and the stress state,deformation and damage of sealing wall under the influence of advanced mining and different water head heights(6,9,12 and 15 m)were analyzed.The stress and displacement monitoring systems of the waterproof sealing wall in the underground goaf has been developed.Based on the theoretical analysis,the monitoring points had been reasonably arranged and applied in the field.On this basis,combined with theoretical analysis and numerical simulation results,the maximum safe head height of the waterproof sealing wall and the head height of the warning water line are determined.The results showed that the advance mining has a certain impact on the damage of the waterproof sealing wall,and the water pressure increases the sliding range of the cracks between the sealing wall and the coal pillar contact surface.The maximum water head height borne by the waterproof sealing wall at the end of mining is 12 m,and the water head height of the warning water level line of the waterproof sealing wall is 9.6 m.The contact surface between the wall and the coal pillar as well as the top and bottom corners of the closed wall are structural weak surfaces,which are prone to damage.Attention should be paid to strengthening the monitoring or observation of the position of the sealing wall embedded in the coal and rock mass and the top and bottom corners of the sealing wall.If necessary,grouting and plugging can be used to reinforce the weak surface or leakage part of the structure.The research results can provide theoretical basis and application reference for stability monitoring and water pressure resistance evaluation of similar mine waterproof sealing walls.
作者
杜明泽
孔繁龙
费宇
王东昊
DU Mingze;KONG Fanlong;FEI Yu;WANG Donghao(China Coal Research Institute,Beijing 100013,China;State Key Laboratory of Coal Mining and Clean Utilization,Beijing 100013,China;Chahasu Coal Mine,Guodian Construction Investment Inner Mongolia Energy Co.,Ltd.,Ordos 017000,China;School of Mechanics and Civil Engineering,China University of Mining&Technology-Beijing,Beijing 100083,China)
出处
《煤炭科学技术》
EI
CAS
CSCD
北大核心
2023年第5期200-208,共9页
Coal Science and Technology
基金
国家自然科学基金资助项目(52104196)
中国煤炭科工集团有限公司科技创新创业资金专项资助项目(2019-ZD004)
煤科院科技发展基金资助项目(2021CX-I-06)。
关键词
防水密闭墙
采空区储水
承压能力
保水开采
waterproof sealing wall
water storage in goaf
pressure bearing capacity
water-preserved mining
