In recent years, long-term stability evaluation of rock structures has been becoming important increasingly. Especially, in the area of high level radioactive waste, it is necessary to evaluate the stability up to several 10,000 years. However, field measurement results and reliable information concerning the long-term behaviour of rock structures are very limited at present, and the prediction technique of the long-term behaviour has not been thoroughly established.
In this paper, first, the results of field measurement carried out for ten years in galleries at Tono Mine are described and discussed. The deformation was found to follow logarithmic law that is commonly observed in laboratory creep testing. FEM technique together with a constitutive equation of variable compliance type was used to simulate the deformation of galleries for ten years. The reasonable agreement between measured and calculated results was obtained indicating validity of the constitutive equation and the analysis technique.
