Numerical study on floor stability control under high bearing pressure in roadway excavation along filling body

Abstract

In order to solve the problem of roadway surrounding rock support caused by roadway floor heave along the filling body, taking Lu’an Changcun Coal Mine as the engineering background, the advantages and disadvantages of two control schemes such as floor reinforcement and floor pressure relief are analyzed by using FLAC3D numerical simulation software, as well as the deformation law and support effect of roadway surrounding rock under different parameters. The research shows that under the reinforcement scheme, when the floor and slope angle are reinforced together, the floor heave in the excavation process of the working face (i.e. 5 m ahead of the “secondary roadway excavation” and “secondary mining” working face) is reduced by 2.48 times and 2.60 times respectively. Therefore, joint reinforcement of the floor and slope angle is an effective way to control the floor heave. When the pressure relief groove controls the roadway floor heave, it has a great correlation with the slotting depth. When the slotting depth is 2.0 m, compared with the case without slotting, the floor heave in the excavation and mining process of the working face is reduced by 1.82 and 2.49 times respectively. However, floor slotting has the opposite effect on the deformation control of roadway roof and solid coal wall. According to the actual engineering situation of S511 fully mechanized top coal caving face in Changcun Coal Mine, Lu’an, it is suggested to control the bottom drum by means of bottom plate pressure relief and grooving with a grooving depth of 1.5 m.

Keywords

• pressure relief groove
• numerical simulation
• floor heave
• floor reinforcement
• floor pressure relief