Interaction between Backfilling Body and Overburden Strata in Fully Mechanized Backfilling Mining Face

Fully mechanized backfilling mining technology creates possibilities for the extraction of coal trapped under buildings, railroads and water bodies. Based on the fundamental characteristics of overburden deformation in fully mechanized coal backfilling mining and theory of Winkler elastic foundation beam, a mechanical model is found to interpret the interaction between the overburden and the backfilling body in the refilled gob in fully mechanized backfilling mining face. Meanwhile the analytic solution is presented in the paper by analyzing the roof deformation and stress distribution, according to which the condition is obtained to prevent roof collapsing. Moreover, the relation among foundation coefficient, backfilingl height, deformation modulus are derived based on the interaction between backfilling body and overburden. The theory above is introduced to a coal mine and its roof maximum deformation is calculated to be 292.12 mm according to the geological conditions, and it is deduced that the roof will not cave in referring to the first strength theory.