Technology Research And Application Of Repeated Mining In Goaf Of Thick Coal Seam

In this paper,with the background of six mining areas in Tai Ping coal mine,by means of theoretical derivation,numerical simulation and field application.Study on the overburden structure characteristics and its movement rules,roadway tunneling and support,etc.According to the actual initial mining working face mining conditions,studied the drivage construction method,face dust technology and fire prevention safety measures,and probes into the compound mining face underground pressure observation,get the following results:(1)According to the location of the compound mining face layout,respectively,to study the overlying protogenesis and regeneration strata structure,and establish the mechanical model.It is concluded that the roof supported in the middle of coal pillar suffers the maximum stress and the stress concentration.The pressure at the coal pillar is mainly from the downward movement of the roof above the coal pillar.The pressure on both sides of the working face mainly comes from two aspects.On the other hand,the roof on both sides of the working face sinks again under mining.(2)The method of numerical simulation is used to simulate the selection of roadway support mode.The support scheme confirmed is:steel scaffolding was selected to support the surrounding rock of roadway.grouting+steel scaffolding is selected to support the broken surrounding rock in the roadway.(3)In the course of roadway tunneling,a method of roadway tunneling construction in coal seam in goaf is invented to strengthen the leading support of roof during blasting,and to protect the integrity of roof well.(4)Repeated mining work face dust removal,designed a kind of water curtain dust removal device,adsorption into the return air roadway dirty dust in the wind,and greatly improve the air quality of mine.