Study on Controlling Technology for Surrounding Rock in Withdrawal Channel of Full-Mechanized Caving Mining with Large Mining Height Face of Super High Seam

Abstract In order to solve the problems such as serious damage of the withdrawal channel and wall caving of tunnel side at end mining stage of 21604 fully-mechanized caving mining face of Huangyuchuan coal mine, study the deformation of surrounding rock of the withdrawal channel in 21604 working face and the law of destruction based on a large number of measured field data; the results show that when the working face is 10 m away from the withdrawal channel, the maximum roof subsidence is 300 mm, and the axial force of roof anchor rod reaches 52 kN, exceeding the anchoring force of anchor rod (50 kN); when it is 5 m away from the withdrawal channel, the maximum roof subsidence is 610 mm, and the axial force of side anchor rod reaches the peak value of 48 kN; when the working face passes through the withdrawal channel, the borehole stress meter reaches the peak value of 22 MPa, the withdrawal channel is seriously damaged, and the depth of tunnel side wall caving reaches 700 mm at maximum. According to the deformation characteristics of the surrounding rock of withdrawal channel, it is proposed to adopt the grouting reinforcement for the mining side and the anchor mesh cable combined with reinforced support for the non mining side and roof on the basis of the original support. It has been successfully applied in 21605 working face, and the support effect is remarkable.