UK EPBM collapse comparisons

摘要

Following serious failures on two recent major UK tunnelling projects (at Portsmouth and Hull), the British Tunnelling Society (BTS) set up the Closed Face Working Committee to review factual data from causation reports from the two projects. The aim was to identify similarities and differences relating to the two projects and report on any lessons to be learnt or areas of concern worthy of further investigation, and any recommendations for further work. The failure at Portsmouth (T&TI July 2000, p9) happened after 7.8km of the 8km long, 2.9m I.d. Tunnel had been completed. A 15 ring section of lining cracked and deformed, letting water into the tunnel. Deformation of the lining was so severe that it needed replacing. The incident occurred during a shift while the TBM crew were on a break and no work was in progress. The incident on the 10.5km long, 3.6m I.d. Hull tunnel (T&TI March 2002, p37-41) also occurred after considerable tunnelling was complete, in a section of finished tunnel next to a shaft. Failure was progressive over a length with the tunnel collapsing completely.