Abstract:

The complexity of geology and specificity of projectinduced shield cutting tool wear and breakdown is unavoidable after longdistance tunneling of shield, hence shield stop and cutting tool inspection should be carried out. In this paper, the shield chamber opening technology and cutterhead and cutting tool inspection are studied and summarized. And then the stateofart, purpose and risk of chamber opening technology in China are summarized by practice; the chamber opening of slurry shield and EPB shield under atmospheric condition and hyperbaric condition and auxiliary measures are analyzed; and the applicable scope, conditions, working principle, operation procedure and key technologies for shield chamber opening under atmospheric condition and hyperbaric condition are introduced in detail, by taking cutting tool replacement of Yangtze River Shield Tunnel in Nanjing under saturated hyperbaric condition and metro shield chamber opening for example. Finally, the fire operation technology of chamber of a metro shield tunnel and Yangtze River Shield Tunnel in Nanjing under atmospheric condition and hyperbaric condition are presented in detail. The practice, summarization and analytical results show that: (1) There still are many problems in shield chamber opening under hyperbaric condition in China, i.e. imperfect training and certification system, inexperienced team, inadequate evaluation system of production safety license and achievement, immature operation handbook and management of cutting tool replacement under hyperbaric condition, and safety control of fire operation of shield. (2) The shield chamber opening is risky; hence, active chamber opening should be carried out. (3) Although few achievements have been obtained in shield chamber opening and cutterhead and cutting tool repairing, relevant management system for shield chamber opening still needs to be established; new technology still needs to be developed; and technical exchange still needs to be carried out.

Key words: shield chamber opening, cutting tool inspection, cutting tool replacement, fire operation in chamber, risk management