Surrounding rock control mechanism and its application of gob-side driving entry in extra thick coal seam

doi:10.13225/j.cnki.jccs.2016.1571

Abstract：According to the characteristics of gob-side entry driving in fully-mechanized coal mining face at extra thick coal seam (up to 15 m),such as the large scope of mining influence scope,the properties and fissures in surrounding rock,the poor stability of coal pillar,etc.,a high strength collaborative control technology acting on roof was proposed,which consists of high strength and pre-stressed yield-pressure anchor support system,step anchored bundled anchor cable support system,and multiple cable-belt truss support system.Besides,a rigid-flexible collaborative control technology,which composes of high strength anchor,high-tenacity material grouting reinforcement and reinforced concrete wall support systems,was proposed in coal pillar side.Furthermore,the strong bolt supporting system was applied to control the integrated coal beside the roadway of full-mechanized caving mining at extra thick coal seam,and the supporting mechanism was fully analyzed.With geological condition on spot and program experience considered,the support scheme and appropriate process flow of roadway driving along goal were confirmed.The engineering practice shows that the maximum displacement of the two sides of roadway was 65 mm,and that of roof and floor was 57 mm,which first achieved an effective control of surrounding rock of gob-side entry driving in 15 m extra-thick coal seam.