Research On Techiques Of Control Gob-side Entry Retaining Foor Heave In Panyidong Coal Mine

In the process of gob-side entry retaining, roadway surrounding rock faced twice violent disturbances, deformed severely, particularly in terms of the roadway floor, which with large deformation and complicated affecting factors, lead to hard governance. Studied and researched the affecting factors and mechanism of large section gob-side entry retaining floor heave by means of theoretical analysis, numerical simulations, field industry test in this paper, offered theoretical foundation for gob-side entry retaining floor heave controlling.According to geological conditions of Panyidong Mine 1252 (1) face, researched the affecting factors of gob-side entry retaining floor heave, concluded the main affecting factors of floor heave as belows:roadways retained depth, surrounding rock properties, water effects, rheological properties of rocks, mining disturbances and supporting measures. Established and solved the roadway floor heave mechanical models respectively during roadway advancing and entry retaining, calculated the analytic solution and the numerical solution with analytical calculation and numerical simulation. With single factors analysis method, research analyzed and obtained the varying patterns of roadway floor heave volume with roadway buried deep, roadway span, backfill width, backfill stiffness.Pointed reasonable roadway support programme, reasonable cross section area, roadway backfill size, and suitable backfill material selection, and combination the prevention before retaining and the governance after retaining can effectively control gob-side entry retaining floor heave.Applying theory to practice, governed roof and floor and comprehensivly, segmented the coal ride with differential support scheme.Field test results showed an effective maintenance of the roadway surrounding rock stability with reinforcement measures before entry retaining, gob-side entry retaining floor heave have controlled effectively.