The purpose of this study was to investigate the law of roof caving of Gob-side entry retaining. This paper makes a study of the law of caving roof and deformation characteristic through plant stress physical simulation experiment under three conditions: thick immediate roof, thin immediate roof and non-immediate roof. The research shows that the fracture position of basic roof gradually gets closer to backfill as the thickness of the immediate roof decreases. The basic roof breaks at the distance of five meters outside the backfill under thick immediate roof condition; and it breaks above the backfill under non-immediate roof condition. The rotating angle of basic roof and the angle of roof caving increase as the thickness of the immediate roof decreases. The deformation of overlying strata is controlled by the motion state of basic roof and its movement intensity gradually decreases as the thickness of immediate roof increases. The study is valuable for the reduction of greenhouse gas emissions and increasing the recovery rate of coal resources
pillarless gob-side entry retaining, roof caving, deformation characteristic, physical simulation
This work is supported by National Key Research and Development Plan (2017YFC0603001) and the National Natural Science Foundation of China Support (51704276)
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