Study of Reasonable Length of Coal Seam Mining under Different Fault Dips

Abstract

In this paper, the stress and strain distribution in coal seam and fault edge under various fault dips is numerically simulated to study the stability of the barrier pillar and determine the reasonable length of coal seam mining using COMSOL Multiphysics package. Numerical simulations show that remarkable increase in stress around fault edge when coal seam is about 250 m away from the fault with a smaller fault angle and the stability of fault is seriously affected by the mining excavation. While the obvious increase in stress around fault edge can be observed until coal seam is about 200 m or 150 m away from the fault with a larger fault angle and the stability of fault is seriously affected by mining excavation. Numerical results indicate that the larger the fault dip is, the larger the reasonable mining length in coal seam where a fault near coal seam exists. Moreover, the fault with smaller dip is more easily activated to induce the failure of the fault and the occurrence of water inrush in coal mining. To prevent the occurrence of fault failure accident, we need to study the reasonable mining length of coal seam, to ensure the safety production and increase the recovery ratio of coal.