Study on the technology and application of cooperative roadway protection with roof cutting pressure relief and CO2 mineralization and filling

Exploring the possibility of the application of roof cutting pressure relief and filling support collaborative roadway protection technology has important forward-looking significance for deep coal mine mining. This study addresses the large deformation problems of the mining roadway in the 03 working face of a coal mine by proposing the theory of roof cutting and filling collaborative roadway protection. CO2 mineralized filling materials were developed, and the optimal roof cutting scheme was determined through theoretical analysis and numerical simulation. Field roof cutting tests were conducted to validate and optimize the parameters, and the stress and deformation characteristics of roadway surrounding rock in fractured and unfractured areas were monitored. The results show that the optimum drilling parameters are coal pillar side tilt Angle of 15 degrees, height of 35 m, gob side tilt Angle of 13 degrees, height of 25 m, and the theoretical pressure relief effect is the best. When the ratio of coal gangue and fly ash is 9:1, the compressive strength of CO2 mineralized material reaches 10.78 MPa and the residual strength is 5.40 MPa. In practical application, the collaborative protection technology significantly reduces the stress of surrounding rock in the fracturing zone by 36.08% and the displacement by 53.06%, and the stress concentration in roadway is effectively alleviated. The stability of surrounding rock is obviously improved. The research results of this paper verify the practicability and reliability of the cooperative roadway protection technology of roof cutting and pressure relief and CO2 mineralization filling.