Stress field evolution of the working face in irregular coal pillar areas

HAN Guowen; XU Qianhai; JIA Yubo; JI Yingqiang; CHEN Yang

doi:10.19956/j.cnki.ncist.2026.01.022

Abstract：High stress concentration is a prerequisite for the occurrence of dynamic disasters.Understanding the overall distribution of the regional in-situ stress field provides essential guidance for the prevention and control of coal mine dynamic disasters.Taking the coal pillar area of the Tangshan Mine main roadway as the research background,a three - dimensional stress field inversion is conducted using the multiple linear regression method.Based on the least-squares multiple regression analysis,five regression coefficients are ob-tained for the analytical equation:L1= 1.1511,L2= 2.2414,L3= 2.3617,L4= 3.5288,and L5= 2.5271,with a multiple correlation coefficient of r = 0.8961.The inversion results are used to analyze the initial stress field in the coal pillar area and the dynamic evolution characteristics of the coal-rock stress field during the working face extraction.The results indicate that the vertical stress in the No.8 and No.9 coal seams of the roadway coal pillar area ranges from 11.5 to 16.9 MPa,and the maximum principal stress also ranges from 11.5 to 16.9 MPa.The influence of horizontal tectonic movement on the stress field in the coal pillar area is relatively minor.During the extraction of working face T2391,a high degree of stress concentration occurs near the haulage roadway,with a maximum stress of 45 MPa—significantly higher than that near the return airway—indicating that monitoring and control efforts should focus on the haulage roadway side.Conversely,during the extraction of working face T2491,stress concentration is more pronounced near the return airway,with a peak value of 48 MPa,considerably exceeding that on the haulage side;thus,control measures during extraction should primarily focus on the return airway side.