Effect of Pre-Existing Faults on Spatio-Temporal Evolution of In-Situ Stress and Microseismic Distribution
Wu Chengfei
Liao Jie
Yuan Guiqiang
Li Lun
Wen Aojia
Xia Caiyu
Abstract：The occurrence of microseisms in metal mines is closely related to the spatio-temporal evolution of in-situ stress fields and microfractures.The microseisms recorded at the Fankou Lead-Zinc Mine in Shaoguan,Guangdong Province,exhibit a notable characteristic:they mostly occur around the pre-existing faults in the mining area rather than concentrating on the fault zones themselves.This phenomenon may be attributed to the fact that pre-existing faults affect stress accumulation in their surrounding areas,which in turn induces microfractures and triggers microseisms.To verify this hypothesis,this study innovatively applies a meter-scale,high-resolution 3D geodynamic numerical simulation of thermo-mechanical coupling.By considering the underground temperature structure,the study systematically investigates the controlling effect of pre-existing faults on the distribution of the surrounding stress field during the forward evolution process,and further explores the possibility of microseism occurrence.The simulation results show that pre-existing faults disturb the distribution of stress fields,forming high-stress zones in their surrounding areas,which may subsequently induce microfractures and lead to microseisms.Factors such as the width,number,geometric shape,and dip angle of pre-existing faults all influence the distribution of the stress field around them,but they do not alter the characteristics of high-stress zone formation in the vicinity of pre-existing faults.Based on the simulation results,this study concludes that the disturbance of stress fields by pre-existing faults(which leads to the formation of high-stress zones around them)is a potential cause for the triggering of microseisms at the Fankou Lead-Zinc Mine in Shaoguan,Guangdong Province.This conclusion reasonably explains the characteristic that microseismsic in the Fankou mining area mostly occur outside the fault planes.It is suggested that microseismic monitoring should be strengthened at the intersection of Fault F3 and the stratum,so as to provide a reference for the prediction of microseismic hazards in mines.
Keywords：stress fieldspatio-temporal evolutionmetal minemicroseismic engineering geology
Publication Date：2025-10-30
Online Publishing Date：2025-11-11(First online date of this platform, not the publication date of the document)
Pages：17( 4027-4043 )