Public Involvement: The WSP team used a blended concept development and outreach process to help gather valuable input, build advocacy and create excitement for the project. By involving the community early, and developing solutions based specifically on their input, our team ensured that they had ownership and pride in the study, and ultimately in their new bridge. A significant component of our approach involved the assembly of a community and agency led PAC. Committee members acted as representatives for key stakeholders, helping the study team better understand community concerns and priorities. The committee also served as a critical link back to their constituents, sharing the progress of the study, and receiving valuable feedback along the way. The engagement effort proved to be remarkably successful, with all stakeholders taking pride in the design, and the community showing full support for the selected alternative at the Public Workshop.
Technical Approach: Through close collaboration with Volusia County, FDOT and the community-led PAC, a unique and historic replacement bridge design was developed, consisting of open spandrel approaches and a thru-arch main span. The thru-arch main span allowed us to reduce the bridge profile, addressing a primary PAC concern. However, this bridge concept presented several design challenges.
- First, arch bridges of this type typically utilize cast-in-place (CIP) construction, which results in lengthy construction schedules. Due to the required in-line replacement and full detour, the design team approached this structure type in an innovative way. We developed a concept that maximized the use of pre-cast components, including all arch components, so that much of the bridge would be “built offsite”. This “precast initiative” resulted in over 50% of the bridge concrete work being precast rather than CIP and reduced the required construction schedule by over a year.
- Second, the owner’s firm construction budget of $42M. The preferred arch bridge concept would typically require a much larger budget than what was available. We were able to refine the design by developing a prescriptive construction sequence that significantly reduced required foundation materials. The precast design approach also resulted in a “unique” structure that contractors might view as risky. To mitigate contractor risk, we developed a full 3D design and Bridge Visualization sheets that clearly showed how the precast elements had to be assembled. Through feedbacks from several contractors, it is clear that the 3D approach to plan production reduced the “contingencies” that contractors carried in their bids.
