Study On High Prestressed Anchor Rod Support Technology For Roadway Excavation Along Goaf In Yangmei No.5 Coal Mine

In this paper,the deformation control of gob side entry driving in 8103 fully mechanized top coal caving face of No.15 thick seam in Yangmei No.5 coal mine is studied.Using theoretical analysis,the failure mechanism of weak wall and the basis for small coal pillar of 8103 goaf excavation are obtained.The stress distribution of the experimental roadway and the damage of the roof and surrounding rock of the two sides are obtained by field measurement.The maximum yield strength,maximum tensile strength,energy absorbed by impact and elongation of high prestressed anchor rod are measured by laboratory experiments.The influence of roadway tunneling and working face stoping on the deformation of surrounding rock and the influence of various parameters of anchor rod support system on the prestressed field of surrounding rock are analyzed by numerical simulation.Through the above methods,the high prestressed anchor rod support system of8103 return air lane is studied comprehensively and systematically.The main achievements are as follows.(1)the test tunnel with small aperture geological mechanics parameter test methods for in situ testing: roadway of minimum horizontal principal stress 4.29 MPa,7.77 MPa maximum horizontal principal stress and vertical stress is 11.04 MPa,the lower the strength of roof integrity is poor,the remaining period of relatively complete,lane to help poor integrity,local exist obvious hollow zone and fissure,carrying capacity of coal is poor,the direct roof strength is higher.(2)The stability of goaf roadway was analyzed theoretically,and the influence law of roadway excavation and working face mining on the failure characteristics and stability of surrounding rock of the test roadway was studied by numerical simulation method.By comparing different coal pillar widths,roadway plastic zone and displacement distribution,the reasonable coal pillar widths of 8?10m were determined.(3)In view of the problems existing in the current bolt material,such as low strength,difficulty in applying prestress,low level of applied prestress,poor stress state and so on,the high prestressed anchor rod and its components are developed.Through laboratory experiments,the mechanical properties of the high prestressed anchor rod and its components developed in this project are tested.(4)By studying the prestress field of anchor rod support,on the basis of the field anchoring performance test of anchor rod,the prestress distribution characteristics of roadway under different supporting parameters were compared and analyzed through numerical calculation to determine reasonable supporting parameters,and the industrial test was successfully carried out in the underground.