Mechanics coupled model of temporary support-roof and support force control strategy for underground coal mine roadways

Abstract The magnitude and management of temporary support forces in underground coal mine excavation tunnels are essential for ensuring maintaining tunnel safety and stability. We developed a coupling mechanical model of temporary support and roof, grounded in the working principles of temporary support in excavation tunnels, to ascertain the rated support force in the temporary support area. A three-dimensional numerical model was created utilizing the discrete element method to assess the efficacy of the rated support force. The results indicate that the maximum subsidence of the roof in the temporary support area is below 10.5 mm, with no yielding zone detected. We developed a mathematical model for the temporary support force control system and evaluated its performance. To overcome the limitations of conventional control strategies, we proposed two novel methods: (1) a proportional–integral–derivative (PID) controller utilizing the Newton–Raphson optimizer (NRO-PID) demonstrated a convergence speed 89.7% faster than the conventional particle swarm optimization (PSO)-PID during the initial stabilization phase, with an overshoot of less than 1.2%; and (2) an adaptive sliding mode controller (ASMC) effectively reduced the support force tracking error to below 2.5% under dynamic disturbances, in contrast to 8.3% for the standard PID. Simulation and experimental results indicate that the NRO-PID + ASMC support force control strategy markedly improves the effectiveness and safety of temporary support, thus facilitating efficient and secure tunneling operations.