The Stability of Gob-Side Entry Retainingina High-Gas-Risk Mine

Abstract

There are series of problems faced by most of the coal mines in China, ranging from low-coal recovery rate and strained replacement of working facestogasaccumulationintheuppercornerofcoalfaces.Basedonthegob-sideentryretainingattheNo. 18205 workingface ina coal mine in Shanxi Province,theoretical analysis, numerical simulation, and engineeringpractice were comprehensivelyusedtostudythemechanicalcharacteristicsoftheinfluenceofthewidthofthefillingbodybesidetheroadway and the stability of surrounding rock in a high-gas-risk mine. The rational width of the filling body beside the roadway was determined,andaconcreteroadway-sidesupportwithaheadedreinforcement-integrated strength eningtechniquewasproposed, which have been applied in engineering practice. The stability of the filling body beside the roadway is mainly influenced by the movement of the overlying rock strata, and the stability of the surrounding rock can be improved effectively by rationally determining the width of the filling body beside the roadway. When the width of the roadway-side filling body is 2.5m, the surrounding rock convergence of the gob-side entry retaining is relatively small atonly 5% of theconvergence ratio. It has been shown that the figure for roof separation is relatively low, and strata behaviors are relatively alleviated and gas density do not exceedthelimit,whicharethebestresultsofgob-sideentryretaining.There sults of this research can provide theoretical guidance for excavation of coal mines with similar geological conditions and have some referential significance to safety and efficient production in coal mines.