The REACH Pedestrian Bridge
TYLin provided structural engineering services for a new 310-foot-long steel pedestrian bridge that provides a direct connection between the Kennedy Center South Plaza Expansion and the riverfront.
The bridge's main span at Rock Creek Parkway is over 93 feet, which includes a 22.5-foot cantilever. The main span has over a 35-to-1 span to depth ratio. Its superstructure is an asymmetric V-shaped steel box section with orthotropic stiffeners and open and closed diaphragms. Its thin profile – only two feet deep at the thickest point of the superstructure – maximizes views from the buildings to the waterfront and vice versa.
After skewing in plan at the river’s edge, the bridge’s four additional spans slope down parallel to the river. The bridge is supported on five architecturally exposed concrete piers and an abutment located at the base of its ramp. The piers are supported on concrete-filled steel mini-caissons and concrete caps. Rather than bearing directly on the piers, the bridge’s steel cross section is supported by a steel knife plate.
TYLin’s understanding of potential pedestrian-induced vibrations and the effects of wind events was extremely important given the bridge’s asymmetrical section and extreme lightness. Despite the overall bridge assembly occurring over several days, the design and construction team managed to only close Rock Creek Parkway for three days.