The contract for the second–and much larger–phase of the Ten Mile Slide stabilization project on Highway 99 North has been awarded and is expected to get under way as early as this month.
The contract, worth approximately more than $40 million, went to Flatiron Constructors Canada Limited on Aug. 9, and is expected to be completed in the spring of 2021.
“We’re working hard to develop a construction schedule with our contractor; we haven’t received their construction schedule yet but we anticipate them to commence work this fall. My estimate at this time would be towards the end of September,” Ministry of Transportation and Infrastructure project manager Scotty McKenzie said last week.
The phase two main stabilization work includes the installation of tied-back concrete and composite piles below the highway, 200 soil anchors above the highway and reconstruction of the highway with two lanes and a guardrail.
“The soil anchors are support measures that go in upslope, above the highway to help stabilize the landslide to the more secure gravel way down below the surface,” McKenzie said.
“The piles are really used to support the highway; what we’re essentially doing is creating a pile wall beneath the highway which will provide us enough support to be able to reconstruct the highways back to two lanes.”
The first phase, completed in February, included the installation of 44 soil anchors. Following that work and geotechnical assessments, load restrictions on the highway were increased to 27,000 GVW.
“That work was deemed to be very successful.”
The whole project, including emergency work a couple years ago, the completed first phase and the final portion about to commence, comes with a $60-million price tag.
“The phase-one contract was valued at approximately $3.3 million,” McKenzie said.
“Phase two is approximately $42.4 million.”
Drivers can expect delays and temporary road closures during construction.
“Those details will be worked out as we get into the construction phase and the contractor will be responsible for developing a traffic-management plan and communicating those delays to the public. Right now, my estimation would be that the bulk of traffic delays will occur later in the project for the closures when they go to construct the pile wall. The first portion of contract will be very similar to the first phase where there will be minor disruptions while they install the soil anchors upslope.
McKenzie said MOTI has stayed in touch with CN Rail throughout the undertaking, as the railway is also seeking to secure the railbed located above the highway.
“CN’s stabilization project was separate from the ministry’s but we have worked closely with them on data sharing and information sharing throughout the design process,” he said.
Our project is separate from theirs but we’ll essentially accomplish the same objective which is to stabilize the landslide, for them, they’re trying to support the railway, which is further upslope. We’re trying to stabilize the slide to provide enough support to reconstruct the highway.
The nature of the project is such that McKenzie anticipates work will be able to continue throughout the winter.
“We do anticipate that this will be year-round work lasting for approximately 20 months of construction. The soil anchor work and the piling and stuff, a lot of that drilling can be done in winter conditions so we expect the contractor to make the most of their time and construct year-round.”
MOTI will continue to monitor the slide for two years before paving the new section of highway, which the ministry describes as one of the most technically challenging sites in the province to maintain.
“We understand the impact highway conditions have had on the Xaxli’p community, the tourism industry and local businesses,” said Minister of Transportation and Infrastructure Claire Trevena.
“I would like to the Xaxli’p for working closely with the ministry to advance this project, which will mean safer travel through the area for years to come.”
Traffic volume through the section of Highway 99 amounts to about 1,600 vehicles a day, with approximately 19 per cent – or roughly 330 trucks per day–being heavy vehicles.