As part of the Broadway Station Redevelopment Project, Matrix is providing the structural design for the Kentucky Avenue Bridge over the South Platte River and South Platte River Regional Trail. The bridge is a three-span, 179-foot-long, and 81-foot wide vehicular and pedestrian bridge. The bridge spans between US 85 South Platte River Drive and Santa Fe Drive. The bridge features four travel lanes and a 21-foot-wide pedestrian and bike zone connecting the Broadway Station development to the South Platte Regional Trail.
Matrix’s structural engineers prepared the structure selection report for the bridge, including identifying cost-benefit ratios for multiple bridge types and the tie-ins to US-85. Due to flood constraints of the South Platte River, the bridge superstructure had to be shallow, or US 85 would need to be raised to fit a deeper superstructure. Our Team evaluated not only the capital cost and lifecycle cost of the alternatives, but also the impacts to the surrounding community because of lane closures and detours that would be required during construction. As a result, Matrix determined that the most cost-effective and least-impactful structure for the community was a multi-span, adjacent box girder beam bridge that matches the existing roadway grades.
During design, Matrix worked closely with Kraemer North America to deliver the bridge as part of a Construction Manager/General Contractor (CM/GC) delivery method. Matrix oversaw and managed the CM/GC process that saved project owners, Broadway Station Partners, over a million dollars. Our Team also supported Kraemer North America with multiple construction challenges. During construction of the east abutment, it was determined an obstruction at the H-pile locations could not be relocated. Matrix’s structural engineers quickly redesigned the eastern-most span to avoid the conflict and kept the bridge construction on schedule, saving the client hundreds of thousands of dollars in delays and girder refabrication.
Matrix coordinated closely with the City and County of Denver Department of Transportation and Infrastructure (DOTI), Denver Community Planning and Development (CPD), Mile High Flood District, and CDOT for reviews and approvals for this project.