PW Trenchless Culvert rehabilitation Chilliwack September October 2016
The Highways Department had two culverts in need of rehabilitation near the Chilliwack Airport. Both cross under the Highway One Freeway and replacing via Open Cut techniques was not a practical solution.
The first culvert to be repaired was located at Upper Prairie Road and the Highway One. The Culvert was only a few metres to the east of the roadway. This Culvert was cleaned and inspected and a repair was decided as opposed to complete Sliplining. The failures were apparent at the bottom 1/3 of the pipe and with total failure the top 2/3's of the culvert can drop and be catastrophic for the Highway one.
The decision to use this method allowed for a smaller coffer damn as full lengths of new culvert pipe were not needed to be lined up and inserted into the existing culvert. The water was diverted using a pump system.
The repair was to weld in place a bed of structural steel rebar and then encase it in concrete. This forms a new "pipe" in the bottom of the existing culvert and can be done quickly and again almost no excavation.
The lack of excavation around creek and waterways is very important to keeping a healthy balance of fish that use the creeks going through the culverts.
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