Comparison on mine pressure behaviors of different dismantlement methods in fully mechanized top-coal caving
During the terminal mining stage of fully mechanized top-coal caving face with pre-excavation of single(double)retracement roadway in thick coal seam,strong mine pressure behaviors appears in the terminal space,such as coal wall breaking and large deformation of roof,bringing difficulty to the support dismantlement.To study the rational terminal mining method of the continuous face under this working condition,through field investigation,laboratory test,principle comparison,numerical analysis,and field monitoring,the mine pressure behaviors of different dismantlement methods was compared.The result shows that the pre-excavation single dismantlement roadway has the superposition of the advance abutment pressure from the working face and from the roadway(the increase coefficient is 3.37).On this basis,the pre-excavation double dismantlement roadways increase the superposition with the stress of the coal pillar(the increase coefficient is 3.69),and the self-excavation dismantlement roadway has no stress superposed during the terminal mining period(the increase coefficient is 2.53).Meanwhile,the comprehensive comparison of the advance abutment pressure,maximum shear stress,and the principal stress zoning shows that the arrangement of the self-excavation dismantlement roadway at the terminal position has the lowest mining pressure.Therefore,the terminal mining process based on self-excavation dismantlement roadway is established.Based on the monitoring of the deep hole displacement of the roof,the support parameters of terminal mining large section space are designed and verified by pre-stress field simulation.Through field practice,the terminal mining space is effectively supported and the supports are the smoothly dismantled.
thick coal seamfully mechanized top-coal cavingdismantlement roadwayterminal mining methodprestress field
NETL
NSTL
万方数据
