Study on the Method of Pressure Relief and Energy Absorption for Protecting Roadway Under Thick and Hard Roof

Thick and hard roofs are frequently encountered geological conditions during coal mining operations. In such conditions, the deformation of the surrounding rock in roadways due to dynamic pressure disturbances has become a prominent factor that hinders the safe and efficient production of coal mines. To safeguard these roadways from damage, an analysis of the deformation mechanism of the roadway floor was conducted using theoretical analysis and numerical simulation methods. The conclusion drawn from the analysis is that as the roof thickness and hardness increase, the overhanging length of the goaf roof also increases. Additionally, the stress concentration coefficient on both sides of the roadway becomes greater, resulting in deeper and wider damage to the roadway floor. On this basis, a novel pressure relief and energy absorption method (PREAM) composed of combined blasting and constant resistance energy absorption support is proposed, and its effectiveness is verified by numerical simulation and field test. The research results demonstrate that the PREAM, through the coordinated control of pressure relief and support, can effectively reduce the stress on the surrounding rock of the roadway by accelerating the collapse of the roof and reducing the hanging length of the goaf roof, all while ensuring the stability of the roof. This optimization of the stress environment in the roadway significantly reduces the deformation of the roadway floor, achieving the goal of safeguarding the roadway and facilitating safe and efficient production. In addition, the research results provide a scientific basis for the control of roadway deformation under similar conditions. Highlights The deformation mechanism of roadway floor under the condition of thick and hard roof is revealed A new method for joint control of combined blasting pressure relief and constant resistance anchor cable energy absorption is proposed Field tests show that the pressure relief and energy absorption method can effectively protect the roadway