The state Department of Transportation expects to award bids next week and start work in April on the first phases of the new St. Croix River Crossing bridge, a state official told local leaders Tuesday,
Jon Chiglo, MnDOT’s St. Croix bridge project manager, told both the Washington County Board of Commissioners and Stillwater City Council that the contract for work on the Minnesota approach to the new span on Minnesota highways 36 and 95 would be awarded Feb. 15.
“We have short-listed three teams. They all submitted their proposals last Friday and we’re reviewing those proposals,” he said.
Chiglo told commissioners work on the two highways and frontage roads should start in April and finish in 2014. The work includes utility relocation, reconstruction of the Osgood Avenue and Greeley Street-Oak Green Avenue intersections with MN 36, reconstruction of the Beach Road overpass and realignment of other roads.
“We’ve been out there all winter doing soil borings and testing,” he said.
In addition to the approach work contract, Chiglo said MnDOT expects to let the first of two contracts for construction of bridge pier foundations in March. He added that MnDOT wants to see that work finished by the end of the year.
Chiglo said the bridge pier work has been split into two contracts — one for the foundations of the five piers and the other for the piers.
Along with the approach and pier foundation projects, Chiglo said other bridge-related work this year includes finishing the Club Tara parking lot, scenic overlook and a fiber-optic cable project along MN 36 east from Interstate 694 to better coordinate MN 36 traffic signals.
By the end of the year, the Wisconsin Department of Transportation is scheduled to let three contracts for the western half of that state’s approach to the new bridge, according to Chiglo.
The start of bridge construction will impact traffic along MN 36, Chiglo admits. He said MN 36 and 95 would be reduced to single lanes and that two 12-day closures of the MN 36 intersections at Osgood and Greeley Street-Oak Green Avenue are on the construction schedule. But he adds that only one intersection can be closed at a time and that access to businesses along the north and south frontage roads will be maintained during construction.
Chiglo said MnDOT is offering financial incentives to contractors to finish work early.
“It’s really to encourage them, once they get started on construction work,” he said.
Chiglo said the design of the new bridge is “60 percent” complete and that work should be done this summer. He added that some design changes have been made that reduce construction costs for the span. He noted that the bridge will be 110 feet above the river on the Minnesota side and 140 feet above the river on the Wisconsin side.
The hybrid concrete box girder-cable stay bridge will have five, rather than six piers and will need only 40 drilled shafts instead of 90. The bridge will be constructed of 900 segments 18 feet tall, 42 to 44 feet wide and 10 feet long, each weighing about 150 tons, Chiglo told commissioners. The segments would be cast at a nearby location and brought to the construction site, he added.
“One of the challenges is logisitics,” he said.
Another challenge, according to Chiglo, will be constructing a bridge when boaters flock to the St. Croix River.
“Construction of the bridge will have an impact on boating traffic,” he said. “There will not be a complete closure of the channel. There may be a no-wake zone.”
Chiglo added that MnDOT expects to have all necessary permits by the time construction begins.
“We’re working very diligently to acquire all permits, We anticipate they’ll all be in hand by the time we execute the contract,” he said.
To aid in that logistical challenge, Chiglo said MnDOT will set up a bridge project office at 1862 South Greeley St. next month. About 70 MnDOT staff will work out of the facility, which will also be home to contractors’ project offices, he added.
MnDOT also plans holding more open houses in the spring, continue outreach to businesses affected by the two-year approach project and plans with area schools STEM labs to engage students.
Chiglo also assured commissioners that the Lift Bridge would remain open during the bridge project that’s expected to be finished in 2017.
“MnDOT will own that bridge and operate it. That bridge will continue to function through that project and not have to be closed,” he said.