AN APPLICATION OF RISK ASSESSMENT METHOD OF WATER INRUSH IN FRACTURED ROCK MASSES TO ACTUAL UNDERGROUND CONSTRUCTION PROJECT

Abstract

This paper focuses on applicability of risk assessment method regarding cost variation for countermeasure due to unexpected water inrush into the underground facility constructed in fractured rock masses. In this study, the risk assessment method has been applied to the construction of the Mizunami Underground Research Laboratory, which is now under construction by the Japan Atomic Energy Agency. And, the relationship between the amount of information due to the progress of the investigations and the risk regarding cost variation for the countermeasure has been discussed from the viewpoint of the ex-post-facto assessment.