First use of embedded line in tunnel segmentsPaula Wallis reports for TunnelTalk
(5.75km x 3.6m)
Hatch Mott MacDonald
Oct 2009: The Upper Northwest Interceptor 1&2 Project (UNWI 1&2) is the first segmental tunneling project in the world to use a PVC corrosion-protection liner embedded in the tunnel segments. Traylor/Shea JV is 14,500 feet into its 3.6 mile drive with 4,664 feet to go before breakthrough into the UNWI 2/3 Transition Structure reception shaft.
Feedback: First use of a steel plate liner embedded on precast concrete segments was for the second Dartford road tunnel in the UK in the 1970s.