Bridge Analysis and Feasibility Study

IMEG was under contract with the United States Department of Army, US Army Garrison – Rock Island Arsenal Public Works (RIAPW) on Arsenal Island to redeck the Moline-Arsenal Bridge.
The main four spans of the bridge were comprised of a haunched two-girder weathering steel superstructure supporting a composite reinforced concrete deck. The remaining eight spans were comprised of weathering steel-rolled girder sections.

The project involved review of government plans, extensive structural analysis, and a feasibility study. RIAPW prepared a preliminary set of construction plans (intended to follow Illinois Department of Transportation (IDOT) standards and details). Because this project was outside of their standard realm of design, RIAPW selected IMEG to provide a structural analysis to determine the feasibility to stage construct a concrete deck on the existing superstructure.

Multiple live-load combinations were considered, including a special 12-axle design vehicle that transports M1 Abrams tanks off the Island via this bridge. Also included was a list of advantages and disadvantages of stage construction, including length of the project, staging impact on the final quality of product (joints/vibration), and cost and time of closure impacts.

We identified any safety concerns for construction personnel and users, providing analysis of economic impact to local businesses regarding full closure as compared to stage construction, and provided a report narrative with recommendations.