St. Croix River Bridge Foundation


Kraemer constructed 10 deep foundations, footings, and starter columns for five river piers for a new extra-dosed bridge in the St. Croix River. We integrated elements from a traditional cofferdam and a deep-water precast cofferdam to create a hybrid to expedite construction and substantially reduce the depth of the seals needed for a traditional cofferdam. In addition, this system provides a higher level of quality and reduces environmental impacts within the St. Croix National Scenic Riverway. Our innovative cofferdam design allowed us to install sheet pile directly onto the precast floor while above water, greatly reducing impacts to the river bottom and water clarity by eliminating the need to drive pile with a vibratory hammer.