Abstract
This paper describes a study on grouting strategy for crystalline rock. Fisrt, grouting practices used in Nordic coutries are summarized. Their main characteristics are the usage of thick slurry of micro-cement, dense pattern of grout holes and simultaneous injection of plural holes, which enable both of high-level water sealing and shortening of grouting work. To investigate the applicability of thick cement slurry, high-pressure clogging test simulating real grouting work has been conducted. The test results indicated the possibility to prevent the clogging phenomenon of thick cement slurry, i.e. water cement ratio of 1.6, by increasing the inejection pressure gradually.
