Murray Baker Bridge Inspection, Load Capacity Rating, and Rehabilitation

The Murray Baker Bridge carries Interstate 74 and Illinois Route 29 over the Illinois River. Modjeski and Masters (M&M) performed a routine NBIS safety and fracture critical bridge inspection of the bridge in 2012 and 2018. After the inspections, M&M developed load capacity ratings based on the deteriorated condition of the primary superstructure members including the gusset plates of the through truss and pins on the suspended span.

M&M also provided engineering services for the rehabilitation of the bridge. Phase I engineering services included the preparation of a Vessel Collision Analysis, Scour Analysis, Bridge Condition Report, Traffic Management Plan and TS&L to determine cost effective rehabilitative solutions for the deteriorated structure.  As part of the TMP, a region-wide travel demand model was created, and the effects of multiple regional projects was evaluated.

Phase II engineering services were completed for the preparation of final contract plans, specifications and estimates for the proposed solution. Repairs included replacement of the deck and parapets on the truss spans and south approach, significant steel repairs to the truss and floorsystem members and stringer seats, concrete repair at bearing seats, scour mitigation, and structure painting. Extensive structural analysis was performed to determine the behavior of the truss after the 2005 reconstruction which led to the re-development of a profile grade which closely followed the deflection of the truss.