Structural concerns on the Abraham Lincoln Memorial Bridge carrying I-39 over the Illinois River made its rehabilitation vital to the safety of the travelling public. Due to poor performance of the existing precast deck panels and the constant emergence of potholes, the bridge required frequent lane closures to facilitate repairs. The bridge is a dual structure spanning more than 7,100 feet and consisting of 44 spans. The main span over the Illinois River is a 620-foot tied arch, the structure’s signature feature.
Benesch was enlisted by the Illinois Department of Transportation to investigate the structure and provide preliminary and final design plans for deck replacement on a very aggressive schedule. When the project began, Benesch’s inspection of the bridge revealed that expansion rocker bearings replacement and substructure concrete repairs needed to be added to the contract documents. Overall, the project would entail total deck replacement, bearing replacement, bridge seat modifications and substructure repairs along the structure, all of which would be designed within one year.
Benesch worked diligently and submitted over 200 pre-final drawings to the IDOT Bridge Office by the end of June 2006. After receiving and incorporating the Bridge Office comments, final plans were delivered at the end of August. Benesch worked with the Bridge Office continuously during the development of the construction documents so that the Bridge Office would be familiar with all the details in the pre-final plans, allowing the Bridge Office to shorten its review time in order to meet the submittal schedule. Benesch also prepared a full construction schedule, including critical path activities, labor and materials to ensure that construction could be limited to two construction seasons and reduce impacts to the travelling public.