Study On Fully Mechanized Caving Facegob-side Entry Retaining Technology Of Chengzhuang Coal Mine

This paper set the Chengzhuang Coal Mine 4311 fully mechanized caving face of Jinmei Coal Group as engineering background,its mining thickness is 6.3m,retaining roadway's height is 3.2m,this paper uses theoretical analysis,numerical simulation,field test method to study the technology of gob-side roadway retaining.Firstly,based on analysis of the overburden structure and activity patterns of the roof,established roof structure mechanical model to calculate key parameters of backfill;secondly,designed the filling body and lane cable reinforcement parameters based on the results of theoretical calculations and numerical simulation;then,designed remote filling process and backfill picking up roof process;finally,did surrounding rock pressure observation.Results showed that: In roof movement transition period and stable period,we got the relationship of strength and width of filling body,and the relationship of the amount of compression and width;backfill dimensioned length × width × height = 3m × 2 m × 3.2m,7d strength reaches to 9.2MPa,set 400 mm upper part as compressible layer,nine pairs of worn steel is applied to reinforce the backfill;lane basic support using combined support with anchors?mesh and cable,roof reinforcement using 8.4m cable,one row is above the center of retaining roadway,one row is directly above the backfill,and one row is belong the backfill edges of mined-out area side,using 5.3m cable to reinforce coal wall;according to the mine pressure observation rear working face,retaining roadway surrounding rock activity can be divided into three periods: roof movement event period? roof movement transition period and roof movement stable period.The origin section of retaining roadway is 2.8m×3.2m,and stablized section of retaning roadway is 2.3m×2.6m,roadway maintenance effect is overall good.