Stability control of the surrounding rock in development roadways of extremely close-distance lower coal seams is a crucial prerequisite for safe mining in underground coal mines. This study aims to reveal the deformation and failure mechanisms of the surrounding rock in such roadways, taking the extremely close-distance No. 9 and No. 11 coal seams in Dianye No. 1 Mine as the research object. It elucidates the response mechanisms and failure patterns of roadways under such complex mining-induced stresses. The results indicate that the return airway of the No. 11 coal seam is primarily influenced by the mining of the No. 9 coal seam working face and its own excavation. In contrast, the mining of the working face within the same coal seam, due to the presence of protective coal pillars along the roadway, exerts a certain pressure-relief and protective effect on the corresponding roadway section. The study further reveals the evolutionary pattern of the plastic zone morphology in the surrounding rock and clarifies the correlation between stress variations and the plastic zone. The lateral pressure coefficient dominates the failure mode of the surrounding rock, while the magnitude of the principal stress and the strength of the rock mass jointly regulate the extent of failure. The deflection angle of the principal stress directs the propagation path of the plastic zone. A differentiated support design based on the stress zones of the surrounding rock is proposed. Under remnant coal pillars, a trapezoidal roadway section with rock bolting, mesh, and cable support is adopted to utilize the self-supporting capacity of the surrounding rock and the structural characteristics of the strata. In high-stress environments under goaf areas, a arched roadway section with combined support of “rock bolting, mesh, cable, beam, and U-shaped steel supports” is implemented.
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