B&N is leading the preliminary study and final design of the Arena District Connector for the Olentangy Trail. With planned improvements to Nationwide Boulevard and the development of Confluence Village, home to the new Columbus Crew Stadium, the new bicycle and pedestrian bridge over the Olentangy River will connect the existing Olentangy Trail to the transforming downtown area and amenities.
Preliminary engineering studied the location of the abutments of the structure to place the abutments outside of the floodway. A hydraulic analysis of the structure pier in the Olentangy River was performed to determine zero rise in the 100-year flood event. In finalizing the preliminary study of the alignment, a preferred crossing location was identified to coordinate the eastern plaza with the proposed Nationwide Boulevard and Confluence Village improvements and the anticipated private redevelopment of an existing water intake building, creating a venue for residents and patrons to relax and enjoy the area amenities and attractions.
The work will also coordinate with the reconstruction of an existing boat ramp and livery that provides canoe and kayak rental for the downtown Columbus waterfront. The project scope included assessment of the geotechnical borings in the area to determine suitable foundation types for the substructure and to address potential scour issues that are common to riverfront areas. Cultural Resources Environmental Screening has been completed. During the preliminary engineering effort, stakeholder coordination occurred with the City of Columbus Departments and developers in the area.
Additional public and stakeholder engagement was required to coordinate closely with the adjacent project construction related to Confluence Village. Final construction documents were prepared to meet the accelerated schedule to coordinate the opening of the structure with the completion of the Confluence Village area and the new Crew stadium. Additional environmental effort and floodplain permitting was also completed prior to completion of the plans. The opening of the crossing coincided with the first Columbus Crew home game in the new stadium.
Design Cost Containment
While the original scope prescribed a single span pedestrian bridge across the Olentangy River, B&N advised the city that design and construction costs could be reduced by providing a two-span bridge. Typically, adding a pier in the floodway can cause an increase in the 100-year flood elevation and necessitate preparing a Conditional Letter of Map Revision (CLOMR) for FEMA’s review and approval. This can add many months to the design schedule and added cost for the analysis and regulatory coordination. B&N considered the current hydraulic effects of an old abandoned interurban railway bridge pier that had collapsed on the riverbed, along with small existing remnants of an old dam. Through hydraulic modeling, we demonstrated that removing the remnants fully offset the new pier in the river and opened the door to using the more cost effective two-span bridge.
CRPD had long desired to accomplish complete removal of a few small remnants of an old dam that had been mostly removed at some earlier date. B&N determined that the contractor’s temporary river causeway for constructing the new bridge could also be efficiently used to accomplish removal of the small dam remnants, at a much-reduced cost while the bridge contractor was mobilized on site and could perform the work. Folding this ancillary work into the bridge project saved the City having to pay to have prepared stand-alone project plans.