Quantitative Study on the Stress Distribution Characteristics of Coal Rock with Faults

Abstract

To quantitatively describe the distribution characteristics of stress field of coal rock in fault area, a finite element model was established to study the influence mechanisms of different fault parameters on the stress distribution characteristics of coal rock and a prediction model of the tectonic stress field of a fault-containing coal rock was established based on the numerical simulations. The numerical simulation results show that the coal rock in the hanging wall of a normal fault forms an area of disturbance significantly larger than that in the footwall of the normal fault and reverse fault. With the increase in fault throw, the stress concentration factor and fault influence range decrease in both the normal and reverse fault scenarios. Additionally, for both the normal and reverse fault scenarios, with the increase in fault dip angle, the coal rock stress concentration zone gradually collapses to the fault plane and the stress concentration coefficient gradually increases due to the reduction in the area of pressure relief. The prediction model of the tectonic stress field can better describe the quantitative relationship between the fault parameters and the stress of coal rock, which can provide guidance for the excavation design of mining engineering and early warning for possible coal and gas outburst disasters.