Article
UndergroundDevelopment of a Centrifugal Sprayed System for Shotcrete Application
Hiroshi Yamachi, Masataka Uozumi, Yuji Nagano,Youichi Nakano, and Shunsuke Sakurai
Read MoreA new Japanese Ministry of Health document provides regulations and guidelines for the allowable dust concentration in tunnel works. The recommended maximum concen-tration should be less than 3.0 mg/m3 (2.3 mg/y3) at 50 m (164 ft) from the tunnel face. To observe this guideline, it