West Kelowna: Repairs on overpass to take 'a few months’
It will take until at least the end of January, 2012, before repairs to the Westside Road Interchange are complete.
On Nov. 20, facing panels collapsed at the west abutment of the overpass. Since then, Ledcor, the contractor for the project, has been working to repair the damage.
Kevin Baskin, chief bridge engineer with the Ministry of Transportation and Infrastructure, said that during their investigation, engineers also found a similar defect in the wall at the east abutment of the bridge.
"A portion of the backfill behind the east abutment facing panels was removed to inspect the connections. Failures of the soil reinforcement at the connection at the back of the panels, similar to those at the west abutment, were observed," said Baskin.
Repairs at the east abutment will start once the contractor has finalized a repair plan, and that work will likely take “a few months.”
The work that has already been done at the west abutment involves placing shotcrete on the exposed face of the backfill, according to Baskin.
"This protects the backfill face from erosion and starts to build out the new facing system.
"This work does not compromise the ability to do a full repair."
According to Baskin, the failure that occurred is extremely rare.
"This particular retaining wall system is a proven performer; it's used all over North America," said Baskin.
"To the best of our knowledge, this is the first time, anywhere in North America, that this type of facing panel failure has occurred with this wall system."
There is still no conclusion about what caused the failure to the overpass.
"The ministry has retained a world renowned bridge design firm to carry out an investigation of the failure on our behalf. This is being coordinated with Westbank First Nation's engineering team.
"The contractor and the wall supplier's engineers are also doing their own investigation."
Baskin said that experts are focusing on the failure observed in the soil reinforcement bars: Where they are bent to hook into the connection at the back of the panels.
According to Baskin, taxpayers will not be on the hook for any of the repairs, or the investigation.
Evelyn Lube, project communications for the Westside Road Interchange project, said that she is hopeful that the repairs won't delay the opening date of the Nancee Way underpass, which was originally scheduled for the summer of 2012.
"We're very focused on getting this work done. Understanding that the work they would've been doing anyway is going to be delayed while these repairs are happening, the contractor is committed to WFN to make up as much time as (they) possibly can."
According to Baskin, the bridge remains safe.
"We've had an ongoing monitoring process in place since day one. We've seen no movement in the structure. Additional shoring and temporary supports have been put in place as an additional safety precaution."
Motorists on Highway 97 can continue to expect single-lane closures in both directions under the Westside Road overpass nightly between 8 p.m. and 5 a.m. until the repairs are completed.