The Riverwalk and Wildlife Viewing Pier provides pedestrian access to the historic De Pere Lock, Tender House and Government Island and is intended to boost tourist interest by providing a place to view local fish and migratory birds.
Team members undertook the project in two phases: the first involved installation of a hydraulic European-style lift bridge, concrete walks and an elevated steel boardwalk; the second added a pair of viewing piers constructed of concrete girders.
For Phase 1, the contractor assembled a train of 14 barges to convey trucks and cranes across a 100-ft-wide river channel separating mainland and island. During harsh winter weather, crews performed earthwork on frozen subgrade, employing rock sockets to install steel piles into bedrock. They also poured cold-weather concrete, facilitating early completion of work.
Phase 2 began the following fall, with $500,000 in funding contingent on completing work by the end of the year. Water elevation fluctuations along the river posed daily challenges, prompting team members to develop creative methods to continue work, including underwater concrete pours, drilling and rebar installation.
To pour a concrete deck during extremely cold temperatures, crews constructed a temporary structure around falsework and girders to heat the concrete and promote curing.
Due to the precision required to ensure successful operation, the project's centerpiece, a lift bridge, required extensive review by design and construction teams. Following installation of prefabricated components, crews performed only minor adjustments to achieve the clearance required by the U.S. Army Corps of Engineers.
The project team also focused on minimizing adverse effects on surrounding natural and historic resources, with special consideration given to using smaller, lighter materials for railings and bollards rather than taller lighting structures.
De Pere Riverwalk and Wildlife Viewing Pier, De Pere, Wis.
Key Players
Owner City of De Pere, Wis.
GC Janke General Contractors Inc., Athens, Wis.; Zenith Tech, Waukesha, Wis.
Designer GRAEF-USA Inc., Green Bay, Wis.