特厚煤层综放工作面多参量监测预警分析

根据某矿12220工作面特厚煤层综放开采，穿越F16逆冲断层的特殊情况，为保证安全生产及时提供预警信息，采用微震、钻屑量、支架阻力、地表变形多种监测手段综合分析回采过程中的参量变化规律。结果表明:微震活动的峰值能量周期约为3 d，回采间距约为4.5 m，且断层下盘较上盘的微震事件能量更集中；钻屑量的统计分析发现最大值出现在上巷下帮7～11 m和下巷上帮9～11 m范围内，划定该区域为巷帮高应力集中区，并将平均钻屑量3 kg/m作为黄色预警临界值，3.5 kg/m作为红色预警临界值；另外，根据支架前、后柱阻力变化情况，划定了2个连续变化的高压力区，发现在初撑力偏低，甚至不接顶、虚顶情况下，支架梁顶部煤体受自重和构造应力作用易发生准脆性受拉断裂破坏，且在穿越逆冲断层的回采过程中，支架阻力峰值呈现由中下部向上部转移的变化规律；最后，通过对地表走向、倾向测点的变形量数据进行统计分析发现，走向面后84.9～284.8 m范围内下沉量较大，下沉速率增幅明显；而工作面倾向中部下沉量最大，整体下沉变形呈二次抛物型，其中下部下沉速率增幅明显。

Analysis on multi parameter monitoring and early warning of fully mechanized caving face for extra thick coal seam

According to the special situation of fully mechanized caving mining in 12220 working face of a mine with crossing F16 thrust fault,in order to provide the early warning information for the work safety in time,the variation laws of parameters in the mining process were comprehensively analyzed by multiple monitoring means such as microseism,drilling cuttings weight,support resistance and surface deformation.The results showed that the peak energy period of microseismic activity was about 3 days,the mining spacing was about 4.5 m,and the energy of microseismic events at the lower wall of fault was more concentrated than that at the upper wall.The statistical analysis of drilling cuttings weight showed that the maximum value appeared in the range of 7-11 m on dip side of upper roadway and 9-11 m on rise side of lower roadway,and this area was designated as the high stress concentration area of the roadway side.The average drilling cuttings weight of 3 kg/m was taken as the critical value of yellow early warning,as well as 3.5 kg/m as the critical value of red early warning.In addition,according to the change of resistance on the front of the support,two continuously changing high pressure zones were delineated.It was found that the coal body at the top of the support beam was liable to be damaged by quasi brittle tension fracture under the action of self weight and tectonic stress when the initial support force was low or even not connected with the roof or the virtual roof,and during the mining process passing through the thrust fault,the peak support resistance presented the change laws of transferring from the middle and lower parts to the upper parts.Finally,through the statistical analysis on the deformation data of the surface strike and inclination survey points,it was found that the subsidence amount was larger in the range of 84.9-284.8 m behind the strike plane,and the subsidence rate increased obviously,while the subsidence amount at the inclination middle part of the working face was the largest,and the overall subsidence deformation was a quadratic parabolic type,in which the subsidence rate at the lower part increased obviously.