Distribution of in-situ stress and regional structural influence in the Luxin mining area and engineering applications

Abstract In-situ stress is a significant factor in the occurrence of dynamic disasters in coal mines. Measured data from 22 measuring points in the Luxin mining area was analyzed to investigate the distribution of in-situ stress and regional structure action. The results reveal that in-situ stress in the Luxin mining area is predominantly a structure stress, it is mainly manifested in the medium and low stress levels. The maximum horizontal principal stress, minimum horizontal principal stress, and vertical principal stress are 5.47–18.8 MPa, 3-10.15 MPa, and 4.8–12.5 MPa, respectively, all of which exhibit a linear increase with depth. The lateral pressure ratio varies from 0.6 to 2.1, gradually approaching 1 with increasing depth. The differences between maximum and minimum horizontal principal stress range from 2.47 to 9.6 MPa. The predominant direction of the maximum horizontal principal stress in the Luxin mining area is NW. The influence of the F1 and F2 reverse faults alters this direction, with seven measuring points indicating a maximum horizontal principal stress direction of N (21.4°-78.6°) E. From the axis of the Xishan anticline to the bottom of the flanks, the maximum horizontal principal stress generally increases. The F1 and F2 reverse faults cause stress redistribution, leading to fluctuations in the maximum horizontal principal stress in the hanging wall region of these faults. Based on the measured in-situ stress data from Shadunzi coal mine, a roadway support scheme for the S4103 working face was developed, which improved roadway stability.