Study On Backfill Technique Of An Abandoned Roadway Along The Mining Direction In A Longwall Face In Xinyuan Coal Mine

This article focuses on the way to pass through the abandoned roadway technology in Xinyuan Coal Mine 30101 working face at Anji Mining Group,by the comprehensive research of used theory analysis,mechanical analysis,numerical simulation and site measurement etc.Exploring the feasibility of filling with high water material when the working face pass through the abandoned roadway,and putting it into use when 30101 working face Pass through the 3205 abandoned roadway.Finally achieved the desired results.Main findings are as follows:(1)Based on the stress analysis to abandoned roadway,finding that span is the key to influence roadway stability and roadway span decreases to equivalent for the large span roadway.Through the analysis of the four types(Leakage failure,separation failure,shear failure,deformation failure)of damage in gob roof,finding that the roadway will be more prone to the above four types of damage when the working face near the abandoned roadway.It is necessary to support the gob of abandoned roadway.(2)Based on the analysis to traditional way to pass the abandoned roadway,finding that there are some limitations when use the traditional way to pass through the abandoned roadway.The filling body and broken rock will formed the overall structure of the cemen when filling the roadway with high water material.Filling body and the coal body will support the roof,at the same time reducing the equivalent span of the abandoned roadway.Depend on the contrasting to different filling materials costs,finding that that the material with high water filling is the most economical way.(3)Mechanism of filling body act on the roof in abandoned roadway: the filling body can provide support and to ensure that the roof abscission layer do not occur when the roof separation doesn't occurred.Due to the filling body full of roadway space,the roof doesn't have caving space and it will not cave,when the roof separation has occurred.(4)Numerical simulation software FLAC3 D is used to calculate the support parameters,select the strength of 1 MPa as the best solution,and determine the water cement ratio is 8:1.(5)Industrial test is conducted in 30101 working face,filling body produced a significant supporting role,gob although the small deformation,but did not affect the normal mining.It proved that the results of the study are verified.