Mechanical characteristics of mining coal in reverse fault area

Abstract

In order to study the mechanical characteristics of the coal body in the area affected by the reverse fault under the mining path, taking 1503 working face of a mine as the research object, the stress analysis model of the coal body in the area affected by the reverse fault was established, and the change characteristics of the stress concentration degree of the coal body in front of the working face gradually increased with the decrease of the distance between the working face and the reverse fault were calculated, KBJ-60Ⅲ-1 working resistance continuous recorder is used to record the working resistance, which verifies the theoretical calculation results. Then, based on the stress change law of mining coal, the mechanical characteristics test of coal is carried out, and three stress loading schemes are designed to simulate the stress change of mining coal at different distances from the reverse fault. It is concluded that the mechanical characteristic of coal is related to the distance from the reverse fault. The closer the distance from the reverse fault is, the greater the peak value and strain of deviatoric stress of coal is. Compared with M1 coal sample 5 m away from the reverse fault, the peak deviatoric stress and axial strain of M3 coal sample 65 m away from the reverse fault increased by 40.74% and 26.73% respectively. Through energy analysis method, it is concluded that the fracture development characteristics of the mining coal body at different distances from the reverse fault are different. The closer the distance from the reverse fault is, the higher the elasticity of the internal storage of the mining coal body is, and more energy is consumed for coal failure and fracture expansion.

Keywords

• reverse fault
• mining coal body
• mechanics analysis
• triaxial mechanical test
• energy analysis