湾图沟煤矿高强度采动巷道稳定性评价研究

Study on stability evaluation of roadway induced by high-intensity mining in Wantugou Coal Mine

针对高强度采动巷道围岩控制难题,从实验室岩样尺度和现场巷道尺度研究了湾图沟煤矿13405工作面回风平巷围岩稳定性特征。结合单轴压缩试验和声波测试分析了干燥、自然及饱和状态下3组岩样的力学行为差异特征。利用钻孔成像,分析了高强度采动影响巷道围岩裂隙发育分段特征。结果表明:干燥、自然及饱和状态下岩样的单轴抗压强度和弹性模量依次降低,水分的存在极大地降低了岩石的强度和刚度。实煤体段围岩仅在深度1 m范围内发现少量纵向裂隙。高静压段两帮维护效果较差,煤帮裂隙极为发育,存在高量值的离层。动压段巷道顶板完整性较好,两帮均发现较大离层,且超出了锚杆正常锚固范围,严重影响了巷道锚固结构的稳定性。

Aiming at the difficult problem of surrounding rock control in high-strength mining roadway,the stability characteristics of surrounding rock in 13405 working face of Wantugou Coal Mine were studied from laboratory rock sample scale and field roadway scale.Combined with uniaxial compression test and acoustic wave test,the mechanical behavior differences of three groups of rock samples under dry,natural and saturated conditions were analyzed.By using borehole imaging,the characteristics of fracturing development in surrounding rock of roadway affected by high-intensity mining were analyzed.The results show that the uniaxial compressive strength and elastic modulus of rock samples decrease in turn under dry,natural and saturated conditions,and the strength and stiffness of rock are greatly reduced by the presence of water.Only a few longitudinal cracks are found in the surrounding rock of the solid coal body within the depth of 1 m.The maintenance effect of the two sides of the high hydrostatic pressure section is poor,the cracks in the coal side are very developed,and there are high value separation layers.The roof integrity of the roadway in the dynamic pressure section is good,and large separation layer is found in both sides,which is beyond the normal anchorage range of the bolt and seriously affects the stability of the roadway anchorage structure.