Study on advance active support of anchor cable in mining roadway with thick hard roof in Cuncaota No.2 Coal Mine

The traditional single passive advanced support in coal mine has some problems, such as the ventilation area of roadway section is reduced and the labor intensity of workers is high. Based on the geological conditions of Cuncaota No.2 Coal Mine, this paper analyzes the feasibility of anchor cable advanced active support by means of field investigation, theoretical analysis and numerical simulation, and has been successfully applied in the main transportation gateway of 31205 working face. The research results show that the roof of Cuncaota No.2 Coal Mine is thick and has high strength. After roadway excavation, the roof integrity is good, and the development of loose zone is not obvious, which provides a good geological foundation for active support. The advanced support form of “one-time support with anchor net and cable+active reinforcement support with long anchor cable in super front roof” is put forward. Combined with the physical and mechanical model calculation method, it is calculated that the advanced active supporting force of roadway should be not less than 200 kN. The pre-tightening force of the pre-active reinforcement anchor cable is 200 kN, the length is 8 m, and the supporting effect is good when the roadway is arranged in a single row and the row spacing is 2 100 mm, which meets the requirements of theoretical calculation strength. The maximum displacement of the roof and floor in the section affected by the advance stress of the working face is 21 mm, the maximum displacement of the two sides is 23 mm, the maximum displacement of the roof is 6 mm, and the stress variation range of the anchor cable is 1-11 kN. The overall control effect of the roadway is good, and the anchor cable is not affected by mining. The research results can provide a basis for the application of advanced active support technology in mining roadway in similar conditions.