Control Technology and Application for Surrounding Rock Deformation in T-Junction Area of Gob-Side Entry Retaining

Abstract

On the bases of theoretic analysis, numerical simulation, and project practice, stress distribution of surrounding rock and movement characteristics of roof strata in T-junction area of gob-side entry were analyzed. Besides, control technology in T-junction area was proposed after indicating deformation characteristics of different stages in gob-side entry. Results show that there is an inclined block in T-junction area after fracture of main roof and the period when the block is tending to stability is a critical stage of pressure appearance for gob-side entry. Further, three stress zones: in-situ stress zone, abutment pressure zone and low stress zone appear in both strike and dip of mining panel and enhanced support of gob-side entry before excavation should keep away from the abutment pressure zone, which also indicates that deep bolting support can exert the bearing capacity of deep rock mass. Additionally, the whole procedure of surrounding rock deformation can be divided into four stages and deformation in gob-side entry is larger than that of entry excavation, which means that efficient support design should be taken into account. Ultimately, district control technologies for surrounding rock of gob-side entry in back zone, filling zone, and front zone are proposed and it showed a good adaption in project practice of coalmine.