Survey of Exposed Dust of Tunnel Driving Working under Construction with NATM
Deng Guoxiang; Zhao Xuewu(Central Hygienic and Antiepidemic Station ofthe Third Engineering Bureau in Railway Ministry (030006 ))
Time weighted mean concentration of dast is 14.49 mg/m3 in tunnel driving construction withNATM. The most high of this index is 41 .83 mg/m3 aftet explosion in every work teams. These inloading dregs and drilling heles are 22.84 mg/m3 and 6.44 mg/m3 respectively. Time weighted exp osed dust value is 12259.57mg/ (m3 min ) in whole tunnel driving working. The most high of this is7171 .76 mg/(m3. min) during loading dregs and it constitutes 58.5% of total exposed dust value. Theratio of dust-making in every working procedures is 65.53% 18.78% and 15.67% for loading dregs,drilling holes and explosion respectively.
【CateGory Index】： R135.2