Research on width of coal pillar of roadway driving along goaf based on coal-rock stress monitoring

In order to determine reasonable width of narrow coal pillar stability of roadway along goaf in deep mine and working face safe mining that determining t he, taking No. 101 working face of Gaojiabao Mine as the engineering background, the lateral coal stress distribution characteristics of No.101 working face was studie d before and after mining by adopting the method of borehole stress measurement.Thus it provided a measurement basis for determining the width of narrow coal pillar of roadway driving along goaf. Results showed that the peak value location of lateral coal stress was within 13 ~ 17 m off the coal wall and the scope of stress decreasin g zone was 9 m. Roadway driving along goaf within stress decreasing zone would avoid the influence of high abutment pressure and contribute to roadway maintenanc e.Based on the scope of stress decreasing zone measured, the optimized width of narrow segment pillar of roadway driving along goaf of No.103 working face was det ermined to be 6 ~ 7 m by using numerical simulation method.The actual width of narrow coal pillar of No.103 return airway ( driving along goaf) was 7 m.According to s urrounding rock deformation and the force condition of bolt monitoring of No.103 return airway, monitoring results confirmed that deformation of roadway changed sligh tly and the maximum deformation of roof and narrow coal pillar side and working face coal side were 112 mm, 88 mm and 75 mm, and the force of bolt had relatively litt e change, roadway maintenance conditions was good and met safety mining of working face.