Study on microseismic monitoring and measuring of fracture distribution features in mining overburden strata

Based on the microseismic monitoring and measuring results of the fracture ditibution in the mining overburden strata above the coal mining face,the paper analyzed therelationship between the microseismic events ditibution and mining- induced fracture in strata. The emprical formula and the site mine stata pressure montoring and measuring resuts were appied to the comparison stuty on the fracture ditibution features of the mining overburden stata The resuts showed tatalong the vertial lrection,.the microseisnic events o.cured with adistance of 0 ~40 m to the sean was distributed in a high densitythe microseismic events with a dstance of 40~70 m to the seam was distributed in a medum density and the microseismic events with a distance over 70 m was distributed in a lovw densit .Aong the nclination drection of the coal mining face,the microseismic everts was concentrated and ditriuted in hvee aress and they were the conveyor head area 1 45 ~ 90 marea Ⅱ of the coal mining face and 90 ~ 120 m are lⅢ of the coal mining fac.Based on the height(20~70 m above the sean ofthecal mining face) fthe waterconducted zone obtained from the microseismic montoring resut.based on the height ofthe water conducted zone outained fom the empircal formula wa 80 m and couldbe basicall fit.With the advancing forvard of the coal mining face.the energy of the microseismic events vould have periodcl citrituion features.theperodical stepdistance of the microse isnic events was 30 m in average and could be ftld with periodic weighting revealed by the working res stance of the powered support The study achievement could provide a monitoring and measuring method to the study and application on the fracture distribution features of the mining overburden stata.