The Scioto River Pedestrian Bridge is a cable-supported pedestrian bridge structure with a 500-ft cable-supported main span in Dublin, Ohio.
The City of Dublin, Ohio employed a Construction Manager/General Contractor (CMGC) delivery method for the construction of the bridge over the Scioto River. This CMGC procurement method was the first of its kind in Ohio. The bridge provides a sculptural landmark to the city, forming an “S” across the Scioto River and rising to a single tower 169 ft high.
“From the ‘S’-shaped bridge deck to the suspension design and state-of-the-art lighting elements, this is truly a unique bridge,” Megan O’Callaghan, Deputy City Manager/Chief Operating Officer for the City of Dublin, told Roads & Bridges. “It was no easy feat to design, engineer, or build, and we are proud to have worked with a team of global experts on this challenging but rewarding project that has become an instant and highly recognizable landmark in the region.”
The Scioto River Pedestrian Bridge is the world’s largest single-tower “S”-shaped suspension bridge. Michael Baker provided construction management to help the client connect a new multiuse district to the historic center of the city with the 760-ft pedestrian bridge, commonly referred to as The Dublin Link, that also now serves as an iconic landmark.
Utilizing an aesthetically pleasing 169-ft-high reinforced concrete tower to support the suspension cables, the bridge has several post-tensioning multi-strand rock anchors to carry the suspension loads to the main span end pier and abutment, and its 14-ft-wide deck consists of four 65-ft approach spans leading into a 500-ft-long suspension main span with a reverse curve passing through the center of the 169-ft-tall tear-drop shaped pylon.
One of the bigger challenges that Michael Baker managed was coordinating with material suppliers all over the world, including Florida, Italy, and Germany. For example, the cables were fabricated in Italy by one of only three companies in the world that produces the type of suspension cables needed for the unique “S” curve bridge. Then the cables were extensively tested in Germany, before being shipped to the project site.
Fabrication of the girders was also unique since each individual piece was cut specifically for its particular position in the bridge. The contract required that the fabricator of the structural steel be an Ohio DOT-approved supplier. However, the first choice, Tampa Steel, had fallen off ODOT’s approved fabricator list due to several years of inactive use. The Michael Baker CM team was able to certify Tampa Steel per the ODOT certification requirements in order to use them on this project. Without the timely certification of Tampa Steel, the contractor would have been required to select an ODOT prequalified fabricator.
The pedestrian bridge over the Scioto River passes through a concrete pylon tower that resembles the eye of a needle. Designing the pylon shape for construction was one of the most complex pieces T.Y. Lin International was tasked to tackle.
The designer explained that the pylon base had to be built parallel to the river flow to minimize water disturbance and scour. The design team produced detailed 3-D BIM models of the pylon geometry, including all rebar, embedded steel elements, and electrical and lighting to identify and resolve potential clashes between elements. For T.Y. Lin International, the 3-D modeling proved to be extremely valuable for defining the complex twisting shape of the pylon in a way that was constructible for the contractor.
“The complex pylon shape and cable arrangement using a single plane of hangers provided significant challenges during the design of the bridge,” Dan Fitzwilliam, P.E., Senior Bridge Engineer for T.Y. Lin International, told Roads & Bridges. “Seeing the results of the attention paid to those details in the finished structure justifies the vision for the Dublin Link developed by the city.”
Another challenging component for the design team came in the form of the bridge’s “S” curve alignment, which was a necessary design choice for the shape, since the identified landing areas on the east and west banks of the river were not quite aligned with one another. A suspension bridge style was selected, and in order to provide unobstructed views and walkways, the stays could only be attached to one edge of the superstructure.
As construction of the bridge was required to take place in the river, the team had to build a causeway at the beginning of the construction process.
The Scioto River Pedestrian Bridge was set to open over St. Patrick’s Day weekend 2020, complete with opening ceremony. However, as the COVID-19 pandemic heightened, these plans were canceled. Still, the bridge was ultimately opened to the public, with reminders for social distancing guidelines found throughout the area.