Abstract: In order to solve the problems of the obvious dynamic pressure, roof cutting subsidence and large deformation of the gob-side entry retaining in soft and thick coal seam fully-mechanized top-coal caving mining. The dynamic pressure characteristics and deformation mechanism of gob-side entry retaining are clarified, through field investigation, theoretical analysis and numerical simulation. A deformation coordinated support system of gob-side entry retaining arranged along the roof of soft and thick coal seam is proposed. The results show that the mining thickness of fully-mechanized top-coal caving mining is large, when retaining the gob-side entry along the coal seam floor, the bearing capacity of the coal roof is poor and the bearing capacity between the floor, gob-side entry filling body and roof support system is uncoordinated, which are the main reasons for the obvious dynamic pressure and large deformation of the gob-side entry retaining in the soft and thick coal seam. The proposal of the deformation coordinated support system in gob-side entry retaining along coal seam roof improves the coordinated bearing capacity of the coal wall, roof, floor and gob-side entry filling body, which can effectively ensure the stability of surrounding rock in the soft and thick coal seam gob-side entry retaining. The successful application of the research results to Gu-cheng Coal Mine proves the feasibility of the support system in soft and thick coal seam fully-mechanized coal caving mining gob-side entry retaining.

Key words: soft and thick coal seam, gob-side entry retaining, roadway side support, coordinated deformation