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Week of Sep. 22
Stronger bridges better prepared for earthquakes
Retrofitting work at Veazie bridge. | The Green River Gorge Bridge east of Black Diamond is the last of the 115 seismic projects, marking the completion of a program that will keep key lifeline routes open all across the county when the next earthquake strikes.“Hardening county bridges to better withstand an earthquake is an investment that will one day save lives and keep vital roadways open,” said King County Executive Ron Sims. “Basic infrastructure investments like this may be expensive, but they are well worth the cost.” In 1994, King County kicked of an ambitious plan to improve the seismic safety of county bridges. Sims said given what is known about the seismic vulnerability of the region, it was a critically important – and timely – investment. “It served us well when the Nisqually Earthquake hit in 2001 – not a single county bridge was lost during that big quake,” he said.
Sims said the $22 million seismic retrofit program ensures that key lifeline routes in unincorporated King County will likely remain open and functional in the event of an earthquake. The King County Roads Division maintains almost 200 bridges located throughout the unincorporated areas. These bridges range in age from brand new to more than 90 years old, but all are inspected frequently and undergo regular maintenance to ensure they are safe for the public.Over the years, Sims has made basic infrastructure investment a centerpiece of his administration, calling such work “a fundamental responsibility of government.” In addition to continued funding for the seismic retrofits, in 2007 Sims budgeted money for the Road Services Division to begin a new $16 million program to accelerate the replacement of 57 aging short span bridges. High priority bridges will be re-constructed within 10 years, rather than 20.
The seismic retrofit program targeted the county bridges considered to be most vulnerable to collapse or major damage during an earthquake. The strengthened bridges are located all across the county; some in cities that incorporated or annexed since the program began. Bridges scheduled for replacement or rehabilitation within 10 years were excluded from the program when it was developed.The King County Road Services Division’s project currently underway on the Green River Gorge Bridge is the last bridge in the program to be retrofitted. It was a complex program to manage because the bridges are diverse in location, design, age, condition, and the amount of traffic they carry. A team of in-house staff and consultants developed a retrofit program that approached each bridge as a unique project, yet took the knowledge learned from each previous project to develop engineering efficiencies to save time and money. Seismically retrofitting these bridges had other benefits, as well. For example, the extra piles installed for better resistance to earthquake forces along five bridges on the Woodinville-Duvall Road also gave the bridges better stability during river flooding. And, the projects have also upgraded many load-restricted bridges, eliminating load limit signs.
King County Road Services Division staff has installed a new sidewalk on Cornell Avenue South in the Skyway area using porous concrete. The crew used approximately 200 square feet of porous concrete, which has a different consistency than normal concrete. It is designed to act as a filtering system to allow storm water to flow through, instead of running down the sidewalk and into storm drains or other drainage systems. County engineers specifically designed the project on Cornell Avenue to use porous concrete because it is located in a sensitive area above Lake Washington. The county may use porous concrete on future projects after determining how this sidewalk functions during the rainy season.
The Seattle Mariners close out their 2008 baseball season this week with home games against the Los Angeles Angels and the Oakland Athletics – and Metro will be on hand with game-day transportation. There is special service for the games at Safeco Field to 13 outlying park-and-ride lots. The special service is only available post-game on weekday nights. For this weekend games, there is special service both to and from the park-and-ride lots. The fare for special buses is $3 each way. Metro also has plenty of regular bus service to the stadium area. Use Metro’s convenient online Trip Planner to research which routes provide the best connection from your home or office to the ballpark. See Metro Online for all the Mariners service details. |
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Metro will be offering game-day bus service to Husky Stadium on Saturday, Sept. 27 as Stanford comes to do battle on the gridiron. Eliminate driving and parking hassles on trips to and from Husky Stadium. Your ride is free on any Metro bus when you show your Husky game ticket or ticket stub to the bus driver. There is special shuttle service from eight outlying park-and-ride lots, and three special service routes from downtown Seattle. See Metro Online for all the Husky service details.
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