Tulsa Celebrates the Opening of a New Landmark Pedestrian Bridge over the Arkansas River

The new Williams Crossing connects pedestrians and cyclists with the Gathering Place

Tulsa, Oklahoma – This weekend, Williams Crossing welcomed its first public users across the Arkansas River. As part of the City of Tulsa’s vision for the improved Zink Dam area, schlaich bergermann partner (sbp) was asked to design a new pedestrian bridge that would provide a safe and modern crossing between the east and west sides of the river and replace an existing bridge that was deemed structurally unsound and in need of major repair. The result is the 1,440-ft-long Williams Crossing.

This new symbol for Tulsa provides a connection to Gathering Place, an immense park designed by Michael Van Valkenburgh Associates (MVVA), as well as links to the River Parks and Midland Valley Trails. Williams Crossing is designed for both pedestrian and cyclist access and offers opportunities to stop and enjoy the dramatic river views with seating and lookout areas along the curved 18-ft-wide bridge deck. sbp and MVVA collaborated closely on the design of Williams Crossing to integrate the bridge into the park landscape for a seamless user experience and create a bridge that is an elegant and unique structure for the community of Tulsa.

The bridge was designed in homage to Robert Maillart’s 1933 Schwandbach Bridge near Bern, Switzerland, which is a curved, deck-stiffened reinforced concrete arch bridge. Over the years, sbp has continued to refine Maillart’s elegant deck-stiffened arch concept, first with the 2003 concrete Auerbachstrasse Bridge in Stuttgart, Germany and again with the 2013 hybrid concrete and steel half-arch Footbridge Josenbrücke in Schwäbisch Gmünd, Germany. The extreme slenderness of Williams Crossing’s deck-stiffened steel arches takes this typology a step further.

The deck-stiffened, plate-arch structure is the first of its kind in the US and the bridge is also the first multi-span, plate-arch bridge built in the country.

“We are honored to be part of Tulsa’s riverfront transformation,” says Michael Stein, Managing Director of sbp. “Williams Crossing was an amazing opportunity to create a first-of-its-kind structure while also providing the local community with an exciting, safe, and beautiful new bridge that will be admired by generations of Tulsans to come.”

Lightweight design principles were applied to the bridge’s superstructure to increase the efficiency of the bridge. The semi-integral bridge, which is supported by eleven 120-ft-long arch spans and one 120ft approach span, was designed with extremely slender arches built from 3-1/4″ plate of weathering steel. The thickness of the vertical spandrel plates varies throughout the bridge to provide sufficient stability for live loads and at the same time allow enough flexibility to minimize restraining forces during temperature changes. The composite deck consists of an 18-in-thick reinforced concrete deck and 8ft wide steel plate with stiffeners that were stiff enough to support the concrete weight during construction. Optimized and structurally expressed steel nodes allow for the transfer of loads from the superstructure to the substructure where the arch spans meet. The original concept for the nodes considered cast steel fabrication, but due to cost and lead time advantages, milled nodes from forged steel blocks were utilized instead. To improve the natural hydrology of the river, the total footprint of the piers was reduced (compared to the existing bridge) and the vertical deck clearance was increased to improve resiliency during more frequent 500-year flood events.

At night, the bridge’s illuminated arches reflect on the river below providing a memorable landmark for residents and visitors of the city. The sophisticated lighting design, with lighting fixtures integrated above and below the bridge deck, was developed by Domingo Gonzales and Associates. The construction of the pedestrian bridge began in 2021 and was overseen by Crossland Construction.

Williams Crossing opened this weekend in conjunction with several other pieces of infrastructure that will define a new interface with the river: a new dam to form a safe recreational area known as Zink Lake, a whitewater flume, a nexus of regional trails on either side of the Arkansas River and the Midland Valley Trail, and an additional 5 ½ acres of waterfront park added to Gathering Place. All of this completes a vision of a park on the river conceived a decade ago by the George Kaiser Family Foundation and MVVA. The 1,100-foot-long whitewater flume for kayaking, surfing, and rafting along the riverfront was designed by MVVA in coordination with McLaughlin Whitewater Design Group. The new dam that forms Zink Lake was designed by Jacobs Engineering and Merrick & Company.

According to MVVA Partner Gullivar Shepard, “This addition to Gathering Place will be one of the only places in Tulsa that invites people to explore the Arkansas River’s edge. It begins to shift the city’s relationship to the river, once a treacherous boundary. Wiliams Crossing is a significant step closer to a trail-connected chain of community assets like Gathering Place, Turkey Mountain, River West Festival Park, and Helmerich Park.”