St. Croix Crossing piers completed
The St. Croix River Crossing project hit a milestone in the final days of 2013 when crews completed construction of the piers that will support an extradosed bridge over the St. Croix River that will connect Oak Park Heights, Minn., and the Town of St. Joseph.
All 10 columns can be seen poking out about 16 feet out of the river.
The contractor is still “completing finishing touches on the bridge pier foundations, which includes all foundations/pier work below the river surface at five locations,” according to a statement by Minnesota Department of Transportation (MnDOT) project spokesperson Jessica Wiens.
The work required 40 drilled shafts called caissons, 10 footings and 10 columns, according to Wiens. Four caissons, a footing and a column make up each pier.
The process included drilling the 9-foot diameter steel-cased caissons up to 140 feet below the river’s surface.Then, each caisson was filled with steel rebar and concrete. Workers then poured a concrete footing and a concrete column, both with steel rebar, for each pier.
About 2,095 truckloads of concrete and more than 8 million pounds of rebar were used in the piers, according to MnDOT.
Construction on the bridge began in May 2013, and is scheduled to be completed in fall 2016.
In 2014, workers will begin construction of the piers on the Minnesota shore, according to Wiens. It is possible that a few pre-cast concrete box segments could be installed this year as well. The segments are 10 feet long by 18 feet tall by 44 feet wide. Eventually they would become the bridge’s driving surface.
Meanwhile, work on the Wisconsin side approach is scheduled to ramp up with the spring thaw.