Development and enhancement of grouting technologies in the Mizunami Underground Research Laboratory (Contract research)

Nobuto, Jun*; Mikake, Shinichiro 

In this study, the comprehensive performance of suspension type grouting materials to seal rock fractures encountered in excavation works at deep underground has been checked, and the clogging phenomenon at the entrance of rock fractures has been investigated. Research issues are as follows; Study on grouting concept to secure high-level water sealing, study on the test method to check grout clogging under high injection pressure, study on grouting material which can penetrate into finer fractures. Among these, in the study on penetrability test method, prototype test instruments were made and a series of preliminary tests were conducted.