Engineering Inc. - May/June 2007 - 28

AC E C 2 0 0 7 EnginEE ring Ex CE ll EnCE AwArds h  Perry Street Bridge Replacement, Napoleon, Ohio HNTB Ohio, Inc.—Cleveland, Ohio h  GRANDAwARDs Mokelumne River Project, Woodbridge, Calif. Winzler & Kelly Consulting Engineers—Santa Rosa, Calif. The new 167-foot-long fish passage facility on the Mokelumne River in Northern California is a model for fish passages worldwide. For decades the river was a well-known Coho salmon and steelhead migratory stream. A series of irrigation dams built since 1910 contained crude fish ladders to mitigate migration, which over time became less and less effective. By 1995 no steelhead were counted, and the salmon run was nearly nonexistent. The project team designed the new facility to include pneumatically operated steel gates and three state-of-the-art high- and low-water fish ladders. In the facility’s first year of operation, more than 16,000 salmon passed through the new ladders, and 180 steelhead returned to their upstream hatchery beds. h  The new Perry Street Bridge is a larger, safer and more efficient version of the 1930 landmark it replaced, yet it maintains the original historic design and role as the city’s visual focal point. Time and deterioration had left the original bridge an antiquated two-lane structure that stifled the region’s transportation capabilities. The project team used a unique combination of pre-cast and pre-stressed concrete arch construction schemes to match the original artistry, in addition to drilling through existing piers to allow construction without disturbing the river bottom. The now fourlane Perry Street Bridge successfully incorporates the historic design elements of its predecessor with improved transportation flow and safety for 16,000 daily motorists. WaMu Center/ Seattle Art Museum Expansion, Seattle, Wash. Magnusson Klemencic Associates—Seattle, Wash. The new WaMu Center/ Seattle Art Museum is a gleaming 540-foot-tall office building that houses 4,000 employees for the nation’s fifth largest bank, as well as four floors of Seattle’s most prestigious art collection, in cohesive harmony despite severe space restrictions. To compensate for the narrow building footprint, the project team incorporated a new structural system—Performance-Based Seismic Design— which avoided the need for a bulky perimeter frame. The result expedited construction, increased layout flexibility and reduced the overall project cost. 28 ENGINEERING INC. MAY / JUNE 2007 h  West Side Combined Sewer Overflow Project, Portland, Ore. Parsons Brinckerhoff— Portland, Ore. In response to a state mandate to reduce combined sewer overflow (CSO) discharges into Portland’s Willamette River, the project team designed a 3.4-mile-long, 14-foot-diameter tunnel that crosses under the river to connect to a 160-foot-deep, 220-million-gallonsa-day pump station. The project also includes five 100- to 150-foot-deep shafts to connect the city’s current combined sewer system and the new tunnel to channel sewage and peak storm water flows. Large-diameter slurry-mix-shield tunnel boring machines—the first application of the technology in the U.S.—were used to tunnel through the saturated soils alongside and beneath the river. The project reduces the amount of CSO discharges into the Willamette River, provides a cleaner water resource, increases water-themed recreational opportunities and allows native fish species to thrive.

Engineering Inc. - May/June 2007

Table of Contents for the Digital Edition of Engineering Inc. - May/June 2007