APPLICATION OF A SHOTCRETE SYSTEM USING SLURRY TYPE ACCELERATOR TO A TUNNEL CONSTRUCTION

Abstract

A new shotcrete system using slurry type accelerator has been proposed as a solution of dust problem in tunneling. The slurry type accelerator is prepared by adding water continuously to a powder type accelerator through a pipeline-equipment. This process could be effective to reduce the direct powder jet from the shooting nozzle. The new shotcrete system was applied to the 6th Shizuoka Tunnel, a part of the New Tomei Highway. The effects of the new system were verified through field tests and practical application. It is concluded that the system is effective not only for dust reduction but also for stable strength development not affected by seasonal variation.