LONG-TERM MEASUREMENTS AND ESTIMATION OF TIME-DEPENDENT DEFORMATION OF LARGE SCALE UNDERGROUND CAVERN

Abstract

The time-dependent deformation of rock mass is an important factor to evaluate the soundness of underground caverns and a reliable estimation method of the deformation is needed for the maintenance. Based on long-term measurements, the feature of the time-dependent deformation of the cavern are clarified. As the results, we focus on the compliance variable model proposed by Okubo et al, that can express nonlinear viscoelastic behavior and the over-peak-strength state analytically. Determination methods of parameters of the compliance variable model are proposed and these are utilized to compare with the cavern’s real behavior that has been measured for about ten years since the excavation was completed. Finally, the estimation analysis of the underground cavern deformation is conducted and the long-term stability is evaluated.