Research on the Application of Prefabricated Load-Bearing Structure in Prefabricated Roadway in Filling Body

The re-excavation roadway in the filling body is a common engineering demand in mines. In order to solve the problem of instability and failure of the filling body caused by the excavation disturbance in the filling body and improve the comprehensive economic benefits of the technology, it is proposed to use the filling body formed by membrane bag filling in the goaf and the steel arch frame to form a prefabricated load-bearing structure, reserve the required roadway space, avoid the safety risks caused by roadway excavation, and reduce the difficulty and cost of roadway support in the later stage. Based on the background of a mine goaf, the mechanical model of the load-bearing structure is established, and the analytical solution of the bearing capacity of the steel arch is obtained. The optimal ratio of the membrane bag filling of the load-bearing structure is obtained by indoor test, and the deformation of the surrounding rock and the distribution range of the plastic zone after the formation of the reserved roadway are numerically simulated and analyzed. The results show that the best cementing material is cement : fly ash of 8 : 2, and the ratio of cement to sand is 1 : 3. The vertical displacement of the roof is 45.1 mm, the vertical displacement of the floor is 5.1 mm, and the horizontal displacement of the left side is 55.5 mm. The load on the load-bearing structure is within the allowable range, and the field monitoring results show that the deformation of the reserved roadway is small. The research results can provide reference for the prefabricated roadway engineering in the filling body.