Metra Rock Island District 24 Bridges and Retaining Walls from 18th to 60th Street
| > Metra Rock Island | > Norfolk Southern (PC 29.25) |
| > Norfolk Southern (Wampum) | > Riverdale Disaster |
| > Orchard Road |
Bowman, Barrett & Associates Inc. (BB&A) led a multi-firm team to replace 24 bridges, retaining walls and track between 18th and 60th Streets on Metra's Rock Island District. The new bridges and walls replace structures constructed in the 1890's. The existing bridges are very similar to each other, typically six-bay and three-span bridges, with 66 feet between abutments with few exceptions. The new structures meet Metra's current capacity requirements and the City of Chicago's vertical clearance requirements, as well as enable an alignment that allows higher operating speeds.
Project work tasks include the following:
Preliminary Studies - structural evaluation of existing bridges and walls and capacity rating for future use. We also completed preliminary track alignment.
Structural Design - design and specifications for new through plate girder spans with provision for a future third track and new east retaining walls using anchored sheet piling, anchored soldier beam and lagging, precast concrete modular walls and signal bridge pile foundations. This also includes the coordination of design and specification elements from subconsultants and staging of construction to minimize disruption to Metra service.
Track Design - new horizontal alignment and vertical profile, improving design train speeds, crossover geometry and drainage.
BB&A coordinated with the City of Chicago agencies for permits and coordinated with utility companies.