The St. Croix River Crossing realigns TH 36 over the St. Croix River connecting Oak Park Heights, Minnesota and St. Joseph, Wisconsin; improving connectivity in the region and reducing traffic demands within the city. The new extradosed bridge replaces the Stillwater Lift Bridge built in 1931. The project is being constructed through a split funding partnership between the States of Minnesota and Wisconsin. The pier foundations in the river were constructed in advance of the Project under separate contract. The St. Croix Bridge utilizes 10 to 18 foot variable depth precast segmental and cast-in-place post-tensioned multi-cell boxes for the approach structures and connecting ramps. The main river crossing is comprised of a 7 span continuous cable supported extradosed bridge with 600 foot spans, 18 foot deep superstructure, and pier towers over 200 feet tall. The main unit is built with parallel 3 cell precast segments erected by a deck mounted mobile lifter, connected by a cast-in-place deck link and precast struts, and transversely post-tensioned to produce a continuous deck. All sections within the project include a trapezoidal shaped box with rounded webs.
Corven Engineering is providing segmental bridge construction engineering services to the Lunda/Ames joint venture. This work includes integrated shop drawings for the precast segments and cast-in-place on falsework superstructure, construction analysis, post-tensioning stressing data, step-by-step erection procedures, development and design of stability towers and temporary works, and engineering support during construction.