Veterans memorial bridge: Reimagining the Conventional Arch Bridge

It was the bridge nobody wanted. At least, that was how it felt to Tad Molas and Adrian Moon when 150 opponents packed the house at the first public meeting to discuss replacement plans for Daytona Beach’s Veterans Memorial Bridge.

“The Daytona Beach community was very attached to their bascule bridge, and there was a strong public desire for the replacement bridge to be of similar design, so as not to change the character of the area,” said Moon, who served as the construction project manager for WSP USA on the project. “The plan was to replace it with a high-level bridge, and there were fears that it would forever alter the landscape of the area compared with a low-profile bascule bridge.”

“A high-level bridge was also seen as tougher for the pedestrians and cyclists who used the bascule bridge regularly to cross the canal that separates two parts of the Daytona Beach community,” added Molas, design project manager for WSP. “This was not going to be an easy process … but something worthwhile isn’t always easy. In the end, this bridge benefitted from those early challenges.”

Amazingly, a process that began in 2015 with a large crowd of sign-carrying protesters ended with applause, cheers and praise from the same community that is now welcoming its new Veterans Memorial Bridge with open arms.

WSP designed the replacement of the bridge along Orange Avenue, which spans Daytona Beach’s Intracoastal Waterway. The new bridge follows nearly the same alignment as the existing bridge, which minimized environmental and right-of-way impacts.

The $38 million bridge, which is scheduled to open to traffic in July, is the culmination of a concentrated effort to involve the public directly into the design process to create a greater sense of ownership in the project, while still meeting the budget and the needs of the clients, Volusia County and the Florida Department of Transportation (FDOT).

Save Our Bridge

The 1,885-foot-long bridge features a vertical clearance of 65 feet and a horizontal clearance of 125 feet – dimensions required by FDOT and the Coast Guard to accommodate the boats that use the Intracoastal Waterway.

It was this height, and the anticipated steep grade that would be necessary for the relatively short bridge to clear the channel, that generated the most public opposition. Sure, motorists and pedestrians experienced delays when the drawbridge was activated to accommodate water traffic, but many felt the low profile of the bascule bridge and the unobstructed coastal views were worth this occasional inconvenience.

Before they stepped into the first meeting with the community, Molas and Moon knew they had their work cut out for them. But they also had a plan to turn opponents into advocates.

“The first thing I set out to do at that meeting was to find the champion of the opposition, talk to her and more importantly, listen to her,” Moon said. “We even went out together to take a look at the original bridge, and by the end of the conversation she was sketching ideas she had for the bridge. Hopefully she left that evening realizing that there was no enemy, and that these guys were here to help.”

To help incorporate the community as a partner in design, the county established a Project Advisory Committee (PAC) that included a select but diverse combination of local residents, veterans, business and community leaders and elected officials. Meetings were held a dozen times over the next nine months and were used by Moon and Molos as opportunities to explain technical concepts, receive input and propose solutions for the committee’s approval. This blended concept development and outreach process was critical in building advocacy and creating excitement for the project.

“It didn’t happen overnight, but at each meeting, we would show genuine regard for what the public had to say about the design,” Molas said. “They had a lot of really good ideas and provided a valuable local perspective that deserved our attention.”

Designers introduced refinements to the plan at each meeting, incorporating what had been discussed at the previous meeting. Even when it was a relatively modest but important suggestion – such as the installation of charging stations to accommodate the elderly population who use battery-powered scooters to cross the bridge – it was given serious attention and became an integral part of the plan.

PAC members not only helped the study team better understand community concerns and priorities, but also served as a critical link back to their constituents, sharing the progress of the study and receiving valuable feedback from the public. Ultimately, their endorsement of the bridge design was what turned public enthusiasm in favor of the project.

“The public gradually took ownership of the overall design,” Molas said. “They helped establish the vision, and the engineers and designers worked with the client to find ways to make it work.”

That idea of ownership extended further than either Moon or Molas anticipated, as the committee started viewing the project from the client’s perspective, sometimes suggesting that certain aspects of the project might be unnecessary or too expensive.

Historic Design – Modern Construction Techniques

Much of the community saw the old bascule bridge as an important part of their personal history. It was always there; always a part of their life. It couldn’t just be replaced with a standard bridge. And to properly honor Volusia County veterans, it should be something special.

“As it was going to be a bridge to honor America’s military veterans, we gathered input from veterans on the committee throughout the design process, and they were favoring an arch bridge design that was common in the 1920s and 1930s that looked powerful and formidable – which they saw as a symbol of the strength and perseverance of military veterans,” Moon said.

Incorporating a non-traditional design ran the risk of significantly increasing the cost of the project. Arch bridges of this type typically used extensive and costly cast-in-place (CIP) construction. So the complex bridge design team, led by WSP’s project engineer-of-records Victor Ryzhikov, P.E; and Christopher Vanek, P.E., developed an innovative concept to maximize the use of pre-cast components, including all arch and superstructure components, “A CIP approach was simply not practical today, so we came up with an evolutionary design that precast those segments in the controlled environment of a casting yard, and then brought them to be assembled at the site, sort of like Lego blocks,” Molas said.

The bridge is composed of a pure concrete open spandrel arch bridge with a main span through-deck arch over the waterway. During construction, the beams and main span arches were hoisted into position by cranes, then closure pours were used to connect all the elements together. 

It was these connection points, and the order of their assembly, that Ryzhikov and Vanek focused much of their design efforts towards. The connections must be small, compact, but incredibly rigid and reasonably easy to assemble on site. Although the open spandrel approach spans were constructed only with closure pours, the longer main span through arch required a combination of longitudinal and transverse post-tensioning to create a rigid frame, that could be supported via PT hanger bars over the channel.

As part of the design process, 3D BIM was utilized to verify constructability and accuracy of the complex connection points. The 3D drawings also aided in plans review and were ultimately used by the CEI and contractor for reference during construction.

Pedestrian Friendly Design

The design also achieved another PAC objective – lowering the overall profile of the bridge.

“The arch was a simple way to carry the weight of the bridge from above rather than below, creating a thinner profile over the channel while still meeting the minimum height requirement,” Molas said. “The arch allowed us to create a much shallower deck than conventional designs would, lowering the roadway profile at midspan significantly compared to the nearby segmental bridge that has the same navigational requirements. Though it may not seem like much, it did lower the grade for pedestrians and lowered the overall profile of the bridge. The through-arch design solved a lot of engineering problems for us.”

There were some concerns that the contractor may perceive the unusual precast design approach as risky. So using the same BIM models developed during the bridge design, WSP developed set of 3D design and bridge visualization sheets that clearly showed contractors how to assemble the precast elements. Contractor feedback indicated that the 3D approach to plan production reduced the “contingencies” that contractors carried in their bids.

Another way 3D visualization came in handy was with the use of a 3D printer to create a stunning model of the bridge design.

“It was one of the best ways to help everyone visualize the bridge before construction began and had an impact far beyond all of our expectations,” Molas said. “There was a visually impaired man that attended every meeting, as well as one on the project advisory committee itself, and when we set up the 3D printed model at one of the meetings, he was able to use his hands to help visualize and understand the shape of the structure. That was an amazing moment. Several visually impaired residents were able to experience what the bridge might look like thanks to the 3D model.”

A Community Bridge

The bridge design took into account the needs of the region’s senior citizens, and resulted in a bridge that exceeds the requirements of the American’s with Disabilities Act, featuring a lower grade, wider sidewalks, a walkway that connects the north and south sides with an underpass to avoid crossing in traffic, charge stations for scooters and educational signs in braille.

The completed bridge also includes a series of overlooks for pedestrians and cyclists, offering fantastic views of the coastal city and featuring plaques that tell the story of each of America’s wars as well as recognizing the contributions of military veterans who fought in those conflicts.

“It has really made this bridge a destination for the local community,” Moon said. “There is an educational circuit that begins on the southeast side and ends on the northwest side, where plans are in place to create Veterans Memorial Park.”

The Memorial park plans were also designed by WSP, and although tethered to the bridge project, will be funded and built separately through the support of the county, private donors and veterans’ groups.

Veterans Memorial Bridge is the biggest public works project in the history of Volusia County, and that was a responsibility that Moon and Molas both took extremely seriously.

“As a design team we wanted to lay it all out there, leave no stone unturned,” Moon said. “We recognized that this was an opportunity that does not come along very often. We committed to it from day one to make it the most it can be, took that approach to everything, and expected the same commitment from everyone involved in the design and construction of the bridge.”

Josh Wagner, Volusia County council member and PAC chair, said the community was fortunate to have WSP working on the bridge.

“It is clear that WSP’s goal has been to go above and beyond in every aspect of our community project,” Wagner said. “They have been very sensitive of the costs for the project. As with any project, costs are a major concern. We have benefitted from WSP’s extra efforts to find cost reductions.”

“The great thing we discovered is that anyone can do something like this,” Moon added. “It didn’t require extraordinary funding; but rather a choice made by the owner to do something special, and a commitment to find the best, most efficient ways to make a vision a reality. And equally as important, a philosophical willingness to involve the community in the process as much as possible.”

The post Veterans memorial bridge: Reimagining the Conventional Arch Bridge appeared first on Civil + Structural Engineer magazine.



source https://csengineermag.com/veterans-memorial-bridge-reimagining-the-conventional-arch-bridge/

ليست هناك تعليقات:

إرسال تعليق