Designed by T.Y. Lin International and, at 550 ft long, one of the longest self-anchored, suspension bridges in the world, the new landmark signature $26.8-million Harbor Drive Pedestrian Bridge now serves as a southern gateway to downtown San Diego and fulfills the city’s 100-year vision to link two of its important regional assets: Balboa Park and San Diego Bay.
Joe Tognoli, TYLI vice president and lead bridge designer, says TYLI worked closely with the Centre City Development Corp. (CCDC), owned by the Redevelopment Agency of the city of San Diego on the project, which created a grade-separated pedestrian crossing of six railroad tracks and of Harbor Drive, a four-lane major arterial. After developing four structural concepts, including steel space truss, a cable-stayed bridge, a self anchored suspension bridge and an arched steel shell, and presenting them to the various stakeholders involved, Tognoli says TYLI’s self-anchored suspension bridge design was selected for its aesthetics, cost and suitability for the site.
With a main span of 354 ft, the single-cable self-anchored suspension bridge features a 131-ft-tall pylon and a curved deck that is suspended only along the inside edge, according to TYLI. The pylon itself is inclined at a 60 degree angle and leans over the deck to support the single pair of suspension cables. Thirty-four individual suspenders, which are attached to the main cable, support the 20-ft-wide deck from the top of the railing. Because of its close proximity to San Diego Bay’s marine environment, the bridge was constructed using stainless steel over traditional painted steel.
TYLI adds that the design also took into account aesthetic and cost-effective design elements that can be appreciated by the pedestrians strolling over the iconic structure. This included architectural concrete finishes and textured walking surfaces, as well as stainless steel hand railings and stainless steel aircraft cable mesh for the safety screening and indirect deck lighting. Other project amenities include custom hardscape and landscape at the bridge landing plazas and the central pylon area.
With T.Y. Lin International as engineer of record on the project, other team members included Safdie Rabines Architects, Reyes Construction (prime contractor), Ameco (steel fabricator), Pfeifer (suspender cable supplier) and DSI (post tensioning supplier).