Study on the Mechanisms of Floor Heave in Roadways and Control Strategies via Grooving and Pressure Relief

With the increasing depth of mining operations, roadways experience higher ground stress and pronounced deformation. Elevated in situ stress leads to a continuous rise in vertical stress on surrounding rock. The excavation of roadways and working faces further redistributes the stress field, resulting in more frequent and severe floor heave. To address this issue in the 1232 transportation roadway of Shuguang Coal Mine, a numerical model was developed using the discrete element method (PFC2D) to systematically analyze the impacts of floor stiffness, strength, and joint distribution on heave mechanisms. A mechanical device for underground slotting operations was designed, and the optimal slotting depth was determined through simulation. The results indicate that floor heave stems from progressive failure of composite strata, governed by stiffness, strength, and moment of inertia (influenced by strata thickness and joint development). Effective suppression requires slotting depths to penetrate the shallow fractured zone and reach the load-bearing structure. Stress arching effects significantly mitigate deformation at 2.5 m depth, providing a theoretical basis for optimal slotting design.