Deformation mechanism and control of broken roof under the influence of advance bearing pressure

To ensure the stability of broken surrounding rock under the influence of advance abutment pressure and the reliability of support system, the 21104 working face of Hulusu Coal Mine is taken as the research background. By means of theoretical calculation, numerical simulation and field measurement, a mechanical model of the elastic foundation beam for the deformation of the super front roof is established, the influencing factors of the bending deformation of the roof, the leading bearing pressure and the main controlling factors of the concentration coefficient are determined, and the advance grouting anchor cable reinforcement technology for broken surrounding rock is proposed. The results show that the roof elastic modulus only affects the roof deflection above the roadway, and the side elastic modulus controls the overall bending deformation of the roof. The advanced support pressure and concentration coefficient show a rapid increase followed by a slow increase trend with the advancement of the working face, and finally tend to stabilize. There is a 35 m high stress area in the grouting anchor cable reinforcement test face, the anchor cable has a high abundance coefficient, the surrounding rock deformation is low (<210 mm), and the roof integrity is strong, which verifies the effectiveness and feasibility of this technical means.