Earlier this month, the Contra Costa County Redevelopment Agency cut the ribbon on a new pedestrian and bicycle bridge on Treat Boulevard near the Pleasant Hill BART station.
The $6.8-million Robert I. Schroder Overcrossing forms the centerpiece of the new sustainable Contra Costa Transit Village and was designed by the San Francisco office of global engineering and consulting firm Arup.
Arup was the prime consultant for the more than 800-ft-long, 10-ft-wide bridge, which was named after a former Contra Costa County supervisor and Walnut Creek mayor.
Arup provided structural, civil and geotechnical engineering, as well as lighting design services for the project. Sponsored by the Contra Costa County Redevelopment Agency, it will be an important safety improvement for pedestrians and bicyclists who use the 33-mi Iron Horse Trail.
According to Arup, the main span is supported with cable hangers from two independent steel arch ribs. The arch ribs are supported on a single pile foundation that minimises the foundation width, and they each incline away from the deck. This unique geometry, further accentuated by the curvature of the deck, creates a striking sculptural effect.
Arup’s subconsultants included Donald MacDonald Architects and David Evans and Phil Singer Landscape Architects.
Due to the tight constraints of the site, including many utilities and the desire to preserve the established oak trees along Del Hombre Lane, the project presented significant challenges throughout the design and construction process, says Arup.
The design had to accommodate the physical constraints and multiple utility and transit easements existing in the corridor.
Arup says it developed a design that resolved these constraints while creating a visually-striking bridge based on the well-known principle of the arch structure.
Arup Principal and Project Director Ignacio Barandiaran says, “After a comprehensive design phase and community consultation process, it is exciting to see the bridge completed and ready to be used. It will make the Bay Area’s Iron Horse Trail safer at this busy thoroughfare and provide a new icon for the community. The lighting design is spectacular and enhances the bridge’s striking structural features at night.”
Ignacio adds, “It has been a pleasure working with the Contra Costa County Redevelopment Agency and its director, Jim Kennedy, as well as the Public Works Department to bring this project to fruition. Their persistence and commitment were integral to seeing the project through its many stages of development. Thanks must also go to the nearby property owners who were open to consultation and helped us provide a great outcome for the wider community.”
Arup originally designed four options for the pedestrian and bicycle bridge, with a short-list of three voted on by the local community in 2003 via an internet preference survey.
Other project team firms include Fehr & Peers (traffic lights), SPS Engineers (independent certifier), Robert A. Bothman (general contractor) and TRC-Hanna Group (construction manager).