Vincent Mullins Landfill Bridge

The goal of this project is to design a roadway in Tucson, Arizona, that extends from the existing Sabino Canyon Road south to connect to Kolb Road over the Vincent Mullins Landfill and across Pantano Wash. The roadway would ease traffic conditions at this site, which exceed design capacity during morning and evening peak hours. The project encompasses transportation, hydrological, structural and geotechnical design, and an environmental assessment. The team followed City of Tucson design codes and regulations, load and resistance factor design, and American Association of State Highway and Transportation Officials bridge design manuals during the design process. Different load combinations were used to design the 43-foot bridge deck span, which includes four traffic lanes, two pedestrian pathways, and parapet walls for safety. The team chose a slab design for its constructability. Based on soil types and soil borings, a geotechnical support structure was designed to elevate the span above the Vincent Mullins Landfill. A full hydrological analysis was conducted to evaluate the runoff from a neighboring park into an existing culvert, as well as drainage from the roadway. The Hydrologic Engineering Center’s River Analysis System, or HEC-RAS, developed for the U.S. Army Corps of Engineers, was used to determine if channel improvements were necessary to convey stormwater runoff from the roadway and park to Pantano Wash. Environmental permitting and stormwater pollution prevention plan were completed to satisfy City of Tucson codes.