H&H will serve as the lead movable bridge designer and engineer of record for the earthquake-ready replacement for the Burnside Bridge in Multnomah County. The project will replace a nearly century-old structure with a bridge designed to have a 100-year service life and be seismically resilient, designed to withstand a Cascadia subduction earthquake. At the completion, it will become one of the longest bascule bridges in the world. H&H has been providing engineering services on the bridge for many decades and most recently supported the NEPA environmental process that led to this final design phase.
The new H&H-designed movable bascule span will include four lanes, a combined bicycle path, and pedestrian space, and it will be designed to accommodate future streetcar service. H&H has been providing engineering services for the NEPA process and continues our service through the final design and construction phases.
The project is being advanced through the Construction Manager/General Contractor (CM/GC) procurement model. H&H, as part of the architecture and engineering design team, is working closely with the County, their owner’s representative as well as the CM/GC joint venture to develop a cost-effective design that meets the project goals.
The scope of the design work includes the structural design of the bascule pier, the movable bridge operator’s facilities, and the bascule span superstructure. In keeping with our multi-discipline movable bridge expertise, H&H is also providing design services for the bascule span machinery and electrical and control systems, along with providing the architectural design of the bascule pier and associated movable bridge structures through coordination with the project lead architect.
The existing bridge is a double-leaf, Strauss-patented underdeck counterweight bascule with movable spans weighing close to four million pounds per leaf.
Located in downtown Portland, the bridge crosses the Willamette River, is a critical emergency route, and serves more than 45,000 vehicles daily, along with pedestrians and bicyclists who cross the scenic structure.