A study on the stability of reverse faults and overlying strata movement under mining disturbance

Guo Wenbing; Hu Chaoqun; Zhang Yihui; Ge Zhibo

doi:10.16186/j.cnki.1673-9787.2025030009

Abstract：Objectives The stability of reverse faults and the overlying strata movement pattern under mining influence is investigated to prevent fault activation and instability triggered by mining activities.Methods Through a combination of engineering case studies,theoretical analysis,and numerical simulations,the fault activation mechanism under mining disturbance is systematically analyzed.The susceptibility of fault activation during hanging-wall and foot-wall mining operation is quantitatively assessed and the correspond-ing failure modes and fracture development patterns in the overlying strata are compared.Results The re-sults show that:(1)During hanging wall mining of the reverse fault,both normal and shear displacement vectors of the overlying rock joints approach 0,indicating minimal mining impact on strata movement and fault activation.Although stress concentration is observed near the fault but no slip displacement occurs.(2)During foot-wall mining,the maximum overlying strata settlement is 0.16 m higher than during hanging-wall mining,with greater fracture development height.The normal and shear displacement vectors of the overlying rock joints reach 0.4 m and 1.3 m,respectively.Under the influence of mining,the fault exhibits both stress concentration and activation-induced slip instability.(3)Using the activation risk index Q to evaluate the fault activation risk,foot-wall mining is found to demonstrate higher susceptibility to fault slip activation.(4)The stability criteria for faults during hanging-wall and foot-wall mining are determined to be T/F>0.087 and T/F>11.43,respectively,indicating greater instability risk during foot-wall mining.Significant differences in fault stability are observed between the two mining scenarios.(5)For foot-wall mining,a protective coal pillars with a horizontal distance exceeding 117 m between the working face and the fault is required.Conclusions These results provide critical insights for optimizing coal resource recov-ery while ensuring mining safety in areas affected by reverse fault structures.