Study on the characteristic of overburden rock structure and support system of the retraction channel in layered fully mechanized caving face

Abstract

Aiming at the technical problems of frequent dynamic pressure disturbance of regenerated roof and roadway stability control in the process of forming large-section support return channel under the delamination mining, taking 1200-2 fully mechanized caving face of Baiyinhua No. 4 Mine as the engineering background, numerical simulation and theoretical analysis were adopted. The overburden structure of the lower stratified caving face and the loading characteristics of the roof after the expansion are analyzed, and the breaking forms and the limiting conditions of the roof are given.The combined support scheme of anchor rod + metal mesh + steel ladder belt + I-beam insertion + suspension beam + anchor cable + single pillar is studied to form a set of safe and efficient construction support technology system. Practice shows that this scheme can effectively reduce the roof subsidence, narrow the scope of plastic failure zone, and ensure the stability of roadway surrounding rock during the support withdrawal period. Successfully complete the efficient withdrawal of hydraulic support. The research results can provide a good reference for the roof management and the smooth output of coal resources under similar conditions.