14 / 2021-11-18 09:11:45

Control of Floor Heave in Soft Rock Roadway in the Western Mining Area of China: a Case Study

Soft rock, floor heave, mechanical model, control mechanism, optimized support

Resource Development and Utilization > 8. Mine Engineering Geological Environment and Disasters

The deformation of soft rock roadway caused by floor heave is a major challenge for coal mines in China western mining area. The modification of floor and effective support is a key point. To effectively control floor heave of soft rock roadway, this work considered the headgate at panel 11505 of the Yushujing Coal Mine as a case study. First, based on slip line field theory and limit equilibrium method, the model of floor heave in soft rock roadway was established, considering the deformation and stress characteristics of roadway, the mechanism of floor heave control was analyzed, and an optimized support method was proposed. Then, FLAC software was used to study the displacement, stress and failure zones of the surrounding rock with the original and optimized support. Finally, the feasibility of the support method was verified by field application. The results showed that floor heave is the main form of soft rock roadway deformation, and 500 mm is the most reasonable among the tested thicknesses of the inverted arch. The numerical simulation was consistent with the theoretical calculation of the failure zone. The extrusion failure zone and shear failure zone were mainly affected by tensile and shear failure, respectively. The maximum convergences of the floor heave determined by numerical simulation and field measurement were 220 mm and 240 mm, respectively, which were reduced by 55% and 60% from those with the original support, and the convergence of both sidewalls decreased considerably. The optimized support method control the floor heave well. To provide reference for the control of floor heave of soft rock roadways in the Yushujing Coal Mine and the western mining area of China.