Tweet Share

• Send by email

  Send by email

  

  Assessment and Preservation of Immersion Joints

  Within the scope of the 2nd Coen Immersed tunnel project, the refurbishment of the almost 50 years old 1st Coentunnel was comprised. As two immersion joints showed leakage problems, an analysis was made to detect the causes that led to these leakages and the appropriate mitigating measures that should be implied. This analysis resulted in the decision to ‘only’ take care of the evacuation of the leakage water without any renovation of the failing components of the immersion joints, in order to avoid unacceptable risks during the execution of these renovation works. During the elaboration of this analysis, the public authorities for roads and railways as the tunnel operator and the contractor started up a commission, in collaboration with the Dutch Centre for Underground Construction (COB) to investigate whether similar problems could raise at the other existing immersed tunnels in the Netherlands. The commission comprised experts from several tunnel operators, engineering companies as well as a substantial amount of contractors involved in immersed tunnel projects. After a thorough review of existing data concerning immersion joint details, execution methods and maintenance records of almost all immersed tunnels in the Netherlands and Belgium, the main causes for leakages at immersion joints could be defined. Based upon the resulting fault tree, a protocol for monitoring and possible mitigating measures was elaborated in order to enable tunnel operators to quickly take the right decisions in case of any urgency. Further on, as deformation data of the immersed tunnels during construction as well as during service life seemed to be extremely important to understand possible damages, a proposal for deformation monitoring was enclosed in the study. This article will enlighten the insights gained within this commission and the conclusions as written down in the final version of the report.

  Recipient :

  Name ^* :

  E-mail address ^* :

  ^* Required fields

  Send   or  Cancel

• Print