Study On The Evolution Characteristics Of Energy Damage Of Rock Mass Under Corrosion And Freeze-thaw

Chinese cold regions are widely distributed in land area,and the domestic industrial system is constantly developing and improving,and the coverage of industrial pollution is gradually expanding.As the country continues to increase investment and construction in the field of transportation,transportation infrastructure continues to extend to remote areas of high and cold areas.Therefore,transportation projects in cold areas often face the dual destructive effects of freeze-thaw and corrosion.Engineering bedrocks are mostly heterogeneous rock masses with highly developed structural surfaces.The cracks in the rock masses continuously store and dredge corrosive groundwater,which further aggravates the damage effect of freeze-thaw-corrosion on the rock mass and induces the instability of the engineering surrounding rock.Damage,eventually leading to partial or overall damage and failure of the supporting structure.In summary,the damage evolution mechanism of the physical and mechanical properties of rock masses under the coupled effects of chemical corrosion and freeze-thaw cycles is studied.Based on the energy theory,the initial stress and accelerated stress thresholds for accelerated failure of rock mass deformation are determined,and the surrounding rock deformation and energy follow-up of the engineering site are discussed.The law of time.The research results will have important scientific value and prospects for engineering practice,and will disaster prevention and safety production of underground engineering surrounding rocks such as tunnels.In this paper,physical and mechanical experiments and SEM micro-electron microscope scanning experiments are carried out on marble under the dual coupling effects of corrosion and freezing and thawing,and the degradation laws of marble physics and microstructure characteristics under multi-field coupling are studied.Based on rock damage mechanics Based on energy theory,the constitutive model of rock energy damage mechanics is established by introducing strength calculus damage factor,and the numerical calculation model of tunnel energy damage under multi-field coupling is solved using FLAC^3D finite element software.To achieve the following research results:(1)Developing marble physical parameters measurement and microstructure evolution experiments under different conditions,and obtain the physical characteristics of marble longitudinal wave velocity,mass loss rate,chemical solution p H change and microstructure,and the development law with the change of test conditions.(2)Obtaining the stress-strain test curve through the single and triaxial tests of marble under multi-field coupling,determine the damage variables considering the p H value and the number of freeze-thaw cycles,and establish the marble peak strength attenuation prediction model.(3)Basing on the experimental data of the mechanical properties of the marble,combined with the energy damage theory,the evolution mechanism and law of the total energy U,elastic energy U_eand dissipated energy U_d of the marble are analyzed,and a rock energy damage constitutive model is established.(4)Using FLAC^3D difference software to solve the numerical calculation model based on the established rock energy damage constitutive relayionship,and verify the rationality of the model establishment with test data.The paper has 31pictures,6 tables,and 68 references.