Abstract: Deep coal mining has long been faced with high stress,strong corrosion and high ground temperature coupling environment,and the service performance of grouting anchor cable has been significantly attenuated.It is urgent to establish an analysis method that can characterize the deterioration process of its corrosion strength.Taking Zhaolou Coal Mine as the engi neering background,the influencing factors of grouting anchor cable corrosion were systematically analyzed by combining theo retical derivation with numerical simulation.The corrosion rate model considering chloride ion concentration and temperature effect was constructed,and the time-varying model of corrosion strength degradation of grouting anchor cable was further estab lished.The research shows that the corrosion strength degradation of grouting anchor cable is controlled by the diffusion of cor rosive medium,temperature change and material-interface synergistic degradation,which shows that the bearing capacity and interface bonding performance of anchor cable continue to decay with the service time.The corrosion degree of grouting anchor cable increases with the increase of service time.The corrosion rate reaches 12.83% and the loss rate of ultimate bearing ca pacity reaches 12.53% after 5 years of service.The numerical simulation results show that the deformation and stress redistri bution of roadway surrounding rock are more obvious under the condition of corrosion.The maximum difference of roof center point settlement is 5%,and the maximum difference of roof center line stress is 10.6%.The corrosion effect has a non-negli gible influence on the long-term stability of deep roadway support system. It is of great significance to study the deterioration mechanism and time-varying response of grouting anchor cable corrosion strength for improving the scientificity of deep roadway support design and ensuring the long-term safety of the project.

Key words: deep coal mine,grouting anchor,rustiness,time varying model,numerical simulation