Water Seepage Induced Deformation and Stability Control of Weakly Cemented Soft-Rock Roadway

Abstract Long-term groundwater seepage promotes continuous water–rock interaction, resulting in progressive deterioration of weakly cemented soft rock and posing significant challenges to the long-term stability of underground excavations. To investigate the deformation and failure mechanisms and stability control of argillaceous weakly cemented soft-rock roadways under long-term water-seepage conditions, the 110803 working face in Qingshuiying coal mine was selected as the engineering background. Field investigation, theoretical analysis, numerical simulation, and in-situ monitoring were conducted. The results indicate that the surrounding rock is dominated by argillaceous weakly cemented soft rock and has undergone significant deterioration under long-term water seepage. The original support system is characterized by a weak anchoring foundation, low prestress, and insufficient bearing capacity, which limits effective deformation control. Based on the changes in the slope and deformation rate of the convergence curve, the roadway deformation process is divided into three stages: initial rapid deformation, intermediate accelerated deformation, and late slow deformation. A coupled progressive failure mechanism involving water seepage and three weak links is identified, including water-induced softening and swelling of the roof rock, a weak anchoring foundation, a weak prestress transmission layer, and low surrounding-rock bearing capacity. These factors drive deformation from local damage toward global instability, with water–rock interaction acting as the dominant driving factor. Accordingly, a control strategy of water isolation and threefold strengthening is proposed to isolate water from the surrounding rock and enhance anchoring capacity, prestress transmission, and overall rock-mass strength. A fully enclosed support system comprising roof control, sidewall reinforcement, and floor strengthening is developed. Field application demonstrates that the proposed method effectively reduces roadway deformation and maintains long-term stability, providing a reference for the control of water-bearing soft-rock roadways.