Bridge & Structural Design

Originally constructed in 1926 and rehabilitated in 1983, the existing Canal Street viaduct is comprised of four complex, multi-block, multi-span, reinforced concrete two-way deck slab bridges.

Given the declining condition of these structures, the Chicago Department of Transportation (CDOT) retained us, as part of a team, to inspect and document the bridge condition.

Adjacent to Union Station, the viaduct spans over two Amtrak tracks and to access the underside of the viaduct we coordinated a right-of-entry agreement and flagging with Amtrak.

The Bridge Condition Report (BCR) recommended the replacement of the bridge deck and bents, the rehabilitation of the retaining wall, and the reuse of the below grade foundations.

After receiving approval of the BCR from the Illinois Department of Transportation (IDOT), we prepared type, size, and location (TS&L) drawings, preliminary bridge design, a hydraulic report, and asbestos determination certification. Several obvious street-level ingress, egress, public, and emergency access doors of existing Canal Street tenants required access during construction and we developed concept level maintenance of traffic plans to assess conceptual staging/phasing.

As traffic increased near the O’Hare International Airport, the Illinois Department of Transportation (IDOT) saw the need to widen Cumberland Avenue (IL 171) over the Kennedy Expressway (I-90).

In addition, IDOT had plans to widen/expand I-90 in the vicinity of this project. IDOT tasked us with providing Phase II, final engineering/design services for a new, two span bridge that was eight (8) lanes wide, and approximately 270-feet long.

The center support is located adjacent to two CTA track and consists of a 4-foot-wide solid wall pier on 36-inch diameter drilled shafts cored into rock.

Extensive coordination with the CTA was required due to the proximity of pier removal and construction near their active tracks and station.

To improve operations, the roadway was widened outside the bridge reconstruction limits to allow for additional turn lanes at the adjacent intersections.

Additionally, designed a new spur ramp, from the I-90 eastbound exit ramp directly to Bryn Mawr Avenue, to alleviate congestion along Cumberland Avenue.

As a subconsultant to J.B. Fay Company, we were selected to replace the existing Louisville & Indiana Railroad (LIRC) bridge located in Columbus, Indiana at milepost 40.19.

The replacement bridge was constructed under a Design-Build delivery method and involved the accelerated replacement of LIRC’s bridge over the Flatrock River.

This project was funded by and designed to CSX Standards, with us serving as the Engineer of Record.

The existing bridge was 508-feet long and comprised of seven 30-foot steel deck span girders and two 144-foot-long steel through truss spans and was partially submerged during 100-year storm events. The replacement structure is comprised of eight 30-foot concrete approach spans; one 115-foot ballasted deck through plate girder (TPG); five 34-foot approach spans. The substructure consists of concrete caps founded on two drilled shafts.

A single 96-hour continuous outage was planned for the superstructure change out; during which time the existing bridge would be demolished and the TPG bridge was rolled into place.

We worked with a contractor to develop an initial project concept; incorporating innovative planning/design details throughout the final design, enabling J.B Fay to replace the entire structure and raise the track profile 5-feet, in just 48-hours.

The Lake County Department of Transportation (LCDOT) retained us to provide a Phase I engineering and environmental study and Phase II contract plans for the reconstruction and widening of Washington Street. This also included a grade separation of Washington Street under the Canadian National Railway.

This American Public Works Association (APWA) award winning project utilized a 2-foot track raise to reduce the amount and depth of earthwork required, thereby minimizing impacts to the adjacent community while addressing operational concerns of the railroad.

Additionally, extensive construction staging/phasing coordination was required to maintain rail and highway traffic throughout construction, as well as commuter rail service at the nearby Grayslake Metra Station.

Other improvements included design of a new stormwater pump station, sanitary lift station relocation, retaining walls, Metra station platform modifications, conversion of the drainage system from open to closed, traffic signal modifications, a 10-foot wide shared-use path, and a 6-foot sidewalk throughout the project corridor.

Replacement of the UNI-38-3.21 bridge required a design that could address a structurally deficient crossing while protecting the environmentally sensitive Big Darby Creek in Union County, Ohio. 

The proposed work replaces the existing four-span, five-beam, non-composite deck superstructure with a galvanized, curved steel beam superstructure on the same two-lane curved alignment. The existing vertical profile and horizontal alignment were maintained to limit roadway impacts while meeting geometric and hydraulic clearance criteria. 

The project also includes a non-standard semi-integral abutment conversion, approach slab replacement, pier and abutment rehabilitation, and new bearings. To limit impacts to the creek, we completed a constructability analysis evaluating crane sizes, pick lengths, laydown areas, and work zones that could remain on the approach roadway pavement. 

We also evaluated manual construction methods to reduce full traffic outages and developed maintenance of traffic plans using a detour to minimize construction time while keeping contractor access outside environmentally sensitive areas. 

For Olympic Boulevard and Houbolt Road, the improvements were designed to provide critical access to the RockRun Collection regional mixed-use development in the northeast quadrant of I-55 and I-80.

Our Phase II engineering services included contract plans, specifications, and estimates for improvements along Houbolt Road from I-80 north to Olympic Boulevard, along Olympic Boulevard from Houbolt Road west to Crossroads Drive, and for the extension of Olympic Boulevard on a new alignment to serve the proposed development. 

A key feature is the new bridge over Rock Run Creek and high-quality wetlands. To reduce cost and environmental impacts, we revised the bridge design from the Phase I study, resulting in a shorter structure founded on spread footings due to high rock elevations. The bridge was also designed for a launched construction method to minimize impacts to sensitive environmental resources. 

To support an aggressive schedule, we developed the plans so the work could be let as two separate construction contracts: one for the new bridge and Olympic Boulevard extension, and one for the existing Olympic Boulevard and Houbolt Road improvements.

During construction, an unexpected major sanitary sewer conflict was discovered beneath a proposed bridge pier. We quickly redesigned the bridge span lengths to avoid the conflict while maintaining the fabrication schedule. The project received a 2026 Special Achievement Award from the American Council of Engineering Companies (ACEC) of Illinois Engineering Excellence Awards.

Interstate 80 from Chicago Street to Rowell Avenue was advanced as part of a broader near-term improvement program for the I-80 corridor from Ridge Road to US Route 30 in Joliet, Illinois. 

As part of a joint venture team, we prepared Phase II engineering services, including plans, specifications, and estimates, for the improvement of ten mainline bridges. The work was designed to remain compatible with future long-term plans for additional mainline travel lanes along the corridor. 

Our responsibilities included the PS&E package for rehabilitation of the Chicago Street bridges, complete replacement of the Richards Street bridges, roadway plans, and permit applications for the U.S. Army Corps of Engineers and the Illinois Department of Natural Resources. 

At Chicago Street, the bridge rehabilitation included full and partial depth slab repair, structural concrete repair, jacking and temporary shoring, deck joint replacement, and concrete sealer. At Richards Street, the replacement included a new 181-foot, three-span structure with steel beams, a concrete deck, multi-column bents, spread footings, and drilled shaft foundations. 

The design required careful coordination around complex geometry, including differing profile grades for eastbound and westbound I-80, a horizontal curve beginning within the bridge limits, variable horizontal curvature, and transverse slope transitions. The project was delivered on time and within budget. 

At Geneva Road over the West Branch DuPage River, the first step was to evaluate the existing bridge and determine whether maintenance, repairs, or replacement would best serve the corridor. 

Following bridge inspection and completion of the Bridge Condition Report (BCR), we worked with DuPage County to advance a full bridge replacement option. Hydraulic analysis was performed to determine the clearance needed over the West Branch DuPage River, resulting in a seven-foot profile raise over the river. 

Phase I engineering included complete replacement of the existing bridge structure and elimination of the center pier in the river. Because of the profile raise, the roadway approaches also needed to be reconstructed to tie back into the existing roadway grades. 

The reconstructed roadway and bridge were designed to accommodate a future sidewalk on one side and a future multi-use path on the other. With forest preserve property on both sides of Geneva Road, early coordination with the DuPage County Forest Preserve was also required. 

To support constructability and reduce impacts, we developed a detour option with the County and coordinated the hydraulic, geotechnical, and bridge analyses to optimize the design for the client.