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Zilwaukee, Michigan

The Zilwaukee Bridge carries I-75 over the Saginaw River near Saginaw, Michigan. The precast box girder structures provide for four 12' lanes of traffic in each direction. The bridge to traffic in 1987 after a construction accident delayed construction for over 2 years. Due to the numerous problems and repairs during construction, Michigan DOT requires a detailed engineering inspection and evaluation to be performed every 4 years. Corven Engineering performed the 2009 in-service engineering inspection.


Following recommendations of prior bridge inspection reports, all 150 bearings were removed and replaced, barrier walls repaired and the overlay patched and sealed. Bearing pedestals, plinths and embedment’s were to be reconstructed as part of this rehabilitation. Corven Engineering provided conceptual bridge jacking alternatives and designed temporary works to perform the bearing replacement. As part of Corven Engineering’s role, the bearing replacement plan was modified to eliminate ground based false work supports for the pier jacking procedures, eliminating the disturbance of classified hazardous fill material.​

Corven Engineering Role: In-Service Engineering Inspection. Engineering inspection of substructure and superstructure using electronic data collection tablets, limited invasive inspection of selected post-tensioning (2005), development of Bridge Inspection Report with recommendations for future maintenance, project document organization and electronic storage, updates to the original Maintenance Manual developed in 1987, and Project Scoping Report (by their subconsultant Great Lakes Engineering). Development and Proposal of Conceptual Bridge Jacking Alternatives, Design of Temporary Works to perform the Bearing Replacement.

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