Abstract: Affected by complicated factors such as large section, low strength of coal mass, high in-situ stress, rich water roof and Mudstone floor characterized by rheological, swelling and softening property, the roadway in Ma Jialiang Mine soft coal seam encounters heavy rock surrounding support problems of roof sag and floor heave. Consequently, the safe and orderly production was affected seriously. Taking the main air return way as a primary research object, the paper has studied the law of surrounding rock deformation and failure, reasonable section size and shape, support parameters and floor heave control method by means of field measurement, theoretical analysis, numerical simulation and so on. The research shows that micro cambered arch roof, drain-pipe installed in roof, inverted-arch floor, net and bolt support of whole section are the optimum combination of section form and support scheme. The field application tells that the optimized air return way surrounding deformation can be controlled effectively, which meets the requirements of keeping it stable for a long period. The achievements of this research will offer useful data for large section roadway support in soft coal seam.

Key words: large section, coal roadway, control of surrounding rock