PACIFIC NORTHWEST EDITION
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September 3 2017 Vol. II • No. 18
“The Nation’s Best Read Construction Newspaper… Founded in 1957.” Your Pacific Northwest Connection – Patrick Kiel – 1-877-7CEGLTD – pkiel@cegltd.com WSDOT photo
Northern Idaho...
ITB OKs $65M GARVEE Bond Authorization
Foggy morning view of the future south portal of the SR 99 tunnel — The future northbound SR 99 off-ramp bridge to South Dearborn Street takes shape just west of Seattle’s stadiums in this November 2016 photo. The bridge sits between the northbound tunnel entrance on the left and the northbound tunnel on-ramp to the right.
Seattle’s ‘Small Bridge With Big Promise’ By Lori Tobias CEG CORRESPONDENT
Work in Seattle is nearing completion on what will be the first bridge of its kind anywhere in the world. They call it “the small bridge with the big promise,” a span designed to return to its original shape after a major earthquake. The bridge is an exit ramp that will deposit northbound travelers from the new SR 99 tunnel into downtown Seattle. “The vision, I think, is really quite exciting,” said Tom Baker, state bridge and structures engineer with the Washington Department of Transportation. “The paradigm has been no collapse. In the future we can be
designing for no damage — immediate use by emergency vehicles, commerce, the public. If that comes true, that’s a giant leap forward.” The bridge depends on two cutting edge differences — AKA “flexible bridge” technology — from the traditional usual means of building bridges. “The first and the most crucial are the reinforcing bars called SMA — shape memory alloy,” Baker said. “These bars remember what their original shape was. We not only have to have the bars return to shape, but the concrete surrounding the bars. It’s a concrete that is highly flexible, it has a lot of fibers in it so that as it moves it doesn’t crack and fall away after the bars have moved.” The experiments for combining the
SMA bars with the bendable concrete started 15 years ago at the University of Nevada-Reno earthquake engineering laboratory, where they test new materials to the breaking point. “The kind of tests we have done in the laboratory, we have really pushed things to the limit,” said Professor M. Saiid Saiidi. “We have simulated very strong earthquakes, well beyond the kind of earthquakes that are likely to occur during the lifespan of the bridge. We typically test bridge columns to magnitude -7.5 and -8.” Standard bridge columns fail under that kind of pressure, according a WSDOT project video. But the laboratory tests prove that columns made with see BRIDGE page 8
The Idaho Transportation Board unanimously approved an additional $65 million in GARVEE (Grant Anticipation Revenue Vehicle) bonds to fund projects on U.S. 95 in northern Idaho. The decision came at the board’s Aug. 17 meeting in Coeur d’Alene. The projects are on U.S. 95 from Garwood Road to Sagle. They include a $41 million project to build a new interchange at Idaho Highway 53 and frontage roads to Garwood Road. The project also removes two at-grade signals and completes improvements from the original U.S. 95 corridor study. In addition, the board approved a $23 million project to realign and widen an additional 2 mi. of U.S.-95 to four lanes to the top of Granite Hill, including frontage roads and a grade separation to reduce fatal and serious injury crashes. In addition to funding more GARVEE projects, the board passed a motion directing the Idaho Transportation Department to begin an environmental document to expand Interstate 84 from Karcher Road to Franklin Road in Caldwell, which is estimated to cost approximately $1 million. In April, the board approved $150 million in GARVEE bonds to widen I-84 from Franklin Blvd. in Nampa to the Karcher Road Interchange. Once complete, the corridor study will pave the way for the state to find funding to continue the I84 expansion. With the approval to construct these projects, the transportation board has committed $215 million of the $300 million authorized by the 2017 Idaho Legislature in Senate Bill 1206. (This story also can be found on Construction Equipment Guide’s website at www.constructionequipmentguide.com.)