Rock pressure distribution law of roadway based on displacement back analysis method

Abstract

Taking gob-side entry retaining in Sichuan Coal Group Xuyong No.1 mine as an engineering background, the displacement inverse analysis method is used to calibrate the physical and mechanical parameters test results of coal and rock, and the numerical simulation method is used to analyze the mine pressure distribution law of gob-side entry retaining roadway. Field observation shows that during the working face mining, the maximum relative displacement of roadway roof and floor is 743 mm. Roof subsidence is the main displacement mode of roadway roof and floor. The average roof subsidence is 3.6 times of floor heave, and the numerical simulation result is 3.5 times. The parameter calibration results show that the reduction of elastic modulus and cohesion has a significant impact on the roof and floor approach. At the same calculation step, the roof and floor approach increases with the decrease of elastic modulus and cohesion. When the elastic modulus is reduced to 20%, the maximum value of roof and floor approach increases to 800 mm. The numerical simulation results show that the abutment pressure at the high wall of gob-side entry retaining roadway at the rear of mining face increases significantly, and the abutment pressure distribution is low on both sides and “convex” with the middle height, and the peak value of abutment pressure increases with the advance of working face. The influence range of the average leading abutment pressure of the working face is 77 m.

Keywords

• gob-side entry retaining
• numerical simulation
• parameter reduction
• displacement back analysis method
• pressure distribution