Research on Protective Area of Exploiting Lower Protective Coal Seam and its Feasibility

Abstract

Based on the reasonable consideration of the role of the second main stress in D-P criterion, the distribution of stress and deformation with the method of finite difference was simulated. And the stress relief angles along incline and strike according to the rules of stress and deformation were obtained. Then the protective area resulted from exploiting the lower protective coal seam were acquired. The results show that the stress relief angles along incline are 75.5 and 77.7 degrees, the ones along strike are 78.4 and 83.5 degrees in the sense of protection when the advancing distance is 300m. But the real effective protective area is much smaller. The largest degree of stress relief locates in the protected coal seam corresponding to the upper and middle of the working face. According the simulation results and the water inrush coefficient method of effective water-resisting seam, the water inrush risk area of lower protective coal seam was divided, and the feasibility of exploiting protective coal seam was analysed and judged. Research results are of certain guidance and reference significance in the layout of mining and gas extraction for the similar coal mines.

Keywords

• Lower Protective Coal Seam
• Protective Area
• Numerical Simulation
• D-P Criterion
• Feasibility