基于模型试验的深部煤层合理停采线结构分析

为分析合理停采线的结构,以存在深部煤层回采情况的济宁三号煤矿为背景,通过模型试验的方法,监测上方工作面回采过程中,垂直于回采方向的下方巷道围岩的扰动特征。试验过程中综合运用PAC声发射仪、静态电阻应变仪、数字散斑等仪器,得到下方巷道围岩声发射事件发展、应变量以及巷道整体变形量。模型试验监测相似材料试样单轴压缩过程中的声发射特征,发现声发射结果可以反映相似材料试样的破坏规律;认为停采线结构应包括受影响巷道的开挖影响区范围l_1、工作面回采的采动超前影响区范围l_2,以及避免两区域相互影响的最小安全间距l;通过监测上方工作面回采过程中,下方巷道围岩内的应变及声发射特征得到了l,l_1和l_2的范围,并通过数字散斑监测了上方工作面回采过程中下方巷道的整体变形量。

Analysis of rational shape of stop line in deep coal seam based on model test

In order to obtain the shape of rational stop line，a model test was undertaken to study the disturbing characteristics below roadway with the axis perpendicular to the excavation orientation during the excavation of upper mining face. The test site，Jining #3 coal mine has a deep coal seam. The PAC acoustic emission，static resistance strain gauge and digital speckle are utilized. The events development，the strains at different locations and the overall deformation of surrounding rock below roadway were obtained. The acoustic emission characteristics of similar material were monitored during the uniaxial compression experiment and the results reflected the damage characteristic of similar material sample. It is concluded that the rational stop line should contain the excavation influenced zone l1 of disturbed roadway，the influenced zone l2 ahead of mining face，and the minimum safety distance l to avoid these two zones to influence each other. During the upper mining face excavation，the scope of l，l1，l2 were obtained by monitoring the strain and acoustic emission characteristic of surrounding rock and the total deformation was monitored in below roadway with the method of digital speckle.