Research On Engineering Impact Of F₀ Fault In Tongjie-Manjiazhai Mining Area, Wenshan Prefecture, Yunnan Province

For open-pit mines with faults,the fault zone can provide a continuous weak surface,which has a direct impact on the safety of the entire mine and requires special attention.Only by conducting special engineering research on the fracture geological characteristics can we provide scientific guarantee for the safe production of mines.A large-scale F₀fault developing on the east side of the open pit in the Tongjie-Manjiazhai mining area of Wenshan Prefecture,Yunnan Province,which caused the continuous large displacement creep of the east side along the fault surface,has certain research value.This paper is based on the study of the F0 fault in the Tongjie-Manjiazhai mining area,which concentrates on the structural evolution process of the mining area,the characteristics of the F0 fault,fault mud mechanical characteristics and the impact on the engineering.of course,has gained some achievements.and the author of this thesis hopes it can provide reference for studying such problems:1.Based on the structural theory,on-site indications,rock and mineral identification,and engineering verification,the F₀fault location was verified to lay the foundation for further research.The three-dimensional geological model is used to accurately display the three-dimensional distribution of F₀fault.2.The rock masses near the F₀fault are weakly permeable layers.Combing the fact that the fault mud is dense,with hard plastic condition,it is judged that the F₀fault is a relative water-proof fault.The rationality of the conclusion is verified by the big difference in ion concentration between the water quality on both sides of the fault and small units water inrush in the pumping test,and it was found that the fault mud is basically not affected by water in the underground.3.According to the triaxial test process of fault mud,the stress-strain curve has undergone four stages in sequence:stress adjustment or pore compaction?elastic deformation?elastoplastic deformation?strain hardening or stabilization.When the confining pressure is 50 k Pa,the fault mud finally shows creep variable characteristics,finally showing strain strengthening characteristics above 50k Pa.As the confining pressure gradually increases,the strain strengthening characteristics become more obvious;Based on this feature,as long as good and reasonable measures are taken,the east side can effectively prevent adverse geological effects,and the conclusion can be extended to other projects.4.Using single factor and multiple regression analysis,it is found that the c,?value of F₀fault mud is very low in correlation with depth,pore ratio,dry density and water content.The c and?values of fault mud are mostly concentrated in one interval,which is basically not affected by various physical indicators,and the properties are relatively stable.5.Utilizing the method of diving units by fault combination,the east side will be divided into 8 units by the method of dividing units by fault combination.The activity risk level of each unit can be divided in accordance with the monitoring situation.The FLAC simulation results of the red and orange early warning areas are consistent with the divided risk levels.It is predicted that the overall east will be basically stable after expanded mining,but geological hazards may occur in the divided red early warning areas,and thus the mining plan needs to be adjusted in time.