Numerical Simulation of Deformation and Failure Mechanism of Main Inclined Shaft in Yuxi Coal Mine, China

Abstract

Disturbance stresses can cause deformation and damage to a tunnel’s rock, potentially threatening the mine’s safety. This paper investigates the effects of disturbance damage on the main inclined shaft due to the excavation of an electromechanical chamber in a deep inclined shaft at Yuxi Mine. Specifically, a numerical model was constructed using Midas GTX NX and Fast Lagrangian Analysis of Continua in Three Dimensions (FLAC3D) to match the actual engineering conditions, and to reveal the stresses and deformations in the surrounding rock of the main inclined shaft before and after the excavation of the main inclined shaft, the electromechanical chamber and the head chamber. The results revealed that the surrounding rock stress around the main inclined shaft is significantly influenced by excavation disturbance. The bottom bulge occurred due to the unstable vertical and shear stresses in the bottom coal bed moving into free space. After the excavation of the electromechanical chamber, the maximum displacement of the floor can be increased from 0.35468 m to 0.64301 m, nearly doubled, and a large area of surrounding rock deformation occurs in the inclined shaft falling roadway. Affected by excavation disturbance, the maximum deformation of floor can reach 1.06 m, with a wide fluctuation range. The main area of damage to the surrounding rock was identified, except for the main inclined shaft, which occurred near the intersection of the inclined shaft and the drop level location. This area is mainly affected by superimposed tensile stress damage, prone to large area floor heave and spalling. The research content is expected to provide certain theoretical support in taking measures to deal with the deformation and failure of the surrounding rock in a main inclined shaft.

Mechanism and Control of Asymmetric Floor Heave in Deep Roadway Disturbed by Roof Fracture

“…The near-field area of the roof at the lateral end of the working face closest to the coal pillar was taken as the research scope. According to the distribution law of stopeabatement pressure [28,[30][31][32][33], the mining-affected roadway can be divided into stability zone I, advance mining-influence zone II, and post-mining residual-influence zone III, based on the distance from the working face, among which dynamic-load-impact zone IV will be produced when the working face is pressed. Moreover, the supporting-pressure peak value, distribution range, and distance from the end coal wall in dynamic-loadimpact zone IV > advanced-mining-impact zone II > post-mining residual-impact zone III > tunneling-impact-stability zone I, as shown in Figure 6.…”

Access to Deposits as a Stage of Mining Works

“…Inclined shafts have an inclination of several to several dozen degrees [22][23][24]. They are sinking in a deposit (Figure 5a) or waste rocks, most often in floor rocks (Figure 4b).…”