Abstract: This paper pays main attention on the failure performance and excavation induced interaction of prestressed thru-anchor cable by a case study. In-situ investigation had shown that there were several failure formats of prestressed thru-cable in the Jinping II underground powerhouse. The observed proof also indicated that this kind of break of thru-cables belongs to tensile failure due to unloading deformation and time-dependent rheology of underground caverns. Thus, a new cell model is purposed to describe the interactive relation between thru-anchor cables and reinforced rock. This cable-rock cell model has special structure, i.e. an elasto-brittle cell is employed to representing the mechanical behavior of thru-anchor cables, and a viscoelastic Kelvin-Hooke cell is employed to representing the mechanical response of host rock. Based on this coupled model, several mechanical parameters which influence the cable’s load are discussed, including elastic modulus of cable, elastic modulus of rock, viscoelastic modulus of rock and coefficient of rock viscosity, etc. This discussion can help us to recognize the ambivalent relationship between thru-anchor cable and reinforced surrounding rock.

Key words: large underground cavern, prestressed thru-anchor cable, failure of anchor cable, interactive model of cable and rock