超长工作面过大断面空巷三维应力演化及综合治理技术

为解决超长工作面过大断面空巷极易发生片帮和大面积冒顶等难题，以晋城成庄矿某超长工作面为背景，建立大断面空巷的三维模型，将工作面顶板划分为煤柱顶板、空巷顶板和待采区顶板3部分。通过理论分析，推导了煤柱失稳的判据，并利用FLAC3D数值模拟分析了大断面空巷顶板应力演化过程。结果表明:煤柱宽度W≤40 m时，工作面超前支承应力与空巷超前支承应力在煤柱上叠加，煤柱开始发生塑性变形；W≤10 m时，煤柱顶板应力逐渐达到峰值16.6 MPa，煤柱发生破坏并失去承载能力，工作面超前支承应力向待采区转移，空巷顶板应力达到峰值12.7 MPa。根据空巷顶板应力演化规律，确定高水材料充填支柱支护的合理强度及空巷两帮煤壁注浆加固的时机，辅以空巷锚索梁补强，提出了大断面空巷综合治理措施，现场应用效果良好。 

Three-dimensional stress evolution and comprehensive treatment technology for super-long working face across abandoned roadway with large section

In order to solved the problem of super-long working face across abandoned roadway with large section,which is easy to cause rib spalling and roof falling,based on a super-long working face in Chengzhuang mine of Jincheng,a three-dimensional model of abandoned with large section roadway was established.The roof of working face was divided into three parts:coal pillar roof,abandoned roadway roof and mining area roof.The criterion of pillar instability was deduced and the roof stress evolution process of large section abandoned roadway was analyzed by FLAC^3D numerical simulation.The results show that when the W was equal or less than 40 m,the advance support stress of working face and the advance support stress of empty roadway were superimposed on the coal pillar with the plastic deformation of coal pillar;When W was equal or less than 10 m,the roof stress of coal pillar gradually reached its peak value of 16.6 MPa,and the coal pillar was destroyed and lost its bearing capacity.The roof stress of abandoned roadway reached its peak value of 12.7 MPa.According to the evolution law,the reasonable strength of filling pillar and grouting reinforcement opportunity were identified.The comprehensive treatment technology for abandoned roadway with large section was proposed.