Epstein was responsible for providing Phase II engineering for the structure replacement of two bridges within the Archer Avenue/LaGrange Road/I-294 interchange to the Illinois Tollway under the Illinois Department of Transportation’s jurisdiction.
The existing bridges consisted of three span, steel superstructures with concrete substructures. They include Eastbound Archer Avenue spanning over 79th Street and Westbound Archer Avenue spanning over Southbound LaGrange Road to the Eastbound Archer Avenue ramp. The proposed structures are 82 and 105 feet long, respectively, single span bridges with pre-stressed precast concrete (PPC) I-beams supported on semi-integral abutments with a 45-degree skew to the substructure. The structures are nearly 53 and 39 feet wide, respectively, out to out of deck. Mechanically stabilized earth (MSE) retaining walls wrap around both abutments. Both structures require a profile raise to improve vertical clearances.
Light poles and electrical conduit run through the single slope concrete barrier and underpass lighting on both bridges. The bridges were constructed through staged construction on revised roadway alignments with traffic remaining open at all times. Coordination was required with an adjacent Tollway contract re-designing the interchange at Archer Avenue and I-294.