A key piece in construction of a new north Spokane freeway got under way this week with the start of work on a tunnel for BNSF Railway tracks along North Market Street.
At a quarter-mile in length, the tunnel will consist of 444 pre-cast concrete arch segments now being poured and stockpiled at Central Pre-Mix Concrete Co. in Spokane Valley.
Those arches will be set in place and covered with fill, which will be compacted and paved with concrete to carry freeway lanes across the tracks in the vicinity of Market Street and Hawthorne Road.
Scarsella Brothers Inc. of Seattle is the prime contractor on the project at a cost of $17.3 million.
The project is the sixth in eight separate construction elements being funded with a nickel-a-gallon gasoline tax dating back to 2003.
When completed, the tunnel will allow for the opening in 2009 of the first segment of a north Spokane freeway from the vicinity of Freya Street and Francis Avenue to Farwell Road. The freeway initially will carry one lane of traffic in each direction.
“The end result is a fully drivable link from the vicinity of Francis and Freya to Farwell Road,” said Al Gilson, spokesman for the state Department of Transportation.
By 2011, the route will extend northwestward to present-day U.S. 395 at Wandermere.
At 54 feet in width, the railroad tunnel is being sized to carry a second set of tracks. On Monday, the contractor began clearing work for the construction.
Chuck Prussack, general manager at Central Pre-Mix, said his crews are running five concrete forms for the arches at his company plant. They are using heat to cure each of the concrete segments at a rate of one a day per form. At the end of last week, they had finished 137 of the pieces.
In all, about 18 million pounds of concrete will be used. Each of the pieces is being reinforced with a mesh of welding wire, Prussack said.
The arches are being pre-cast in two pieces, and then will be joined permanently with a pour at the construction site. Each piece weighs about 42,000 pounds. The technique was developed years ago in Europe, he said.
Central Pre-Mix has a $2.47 million subcontract for the work.
In a related matter, the DOT is seeking auction bids on a house at 3312 E. Pacific Ave. that needs to be moved to make room for future expansion of Interstate 90 and its interchange with the north Spokane freeway.
The house is considered historically eligible, and is being put up for bid for a move to another location, Gilson said. It is among about 15 homes that have historic value that DOT is putting up for sale as part of its right-of-way acquisition for freeway expansion in the East Central neighborhood.