As Washington State Dept. of Transportation celebrates the opening of State Route 99 tunnel under downtown Seattle, the new roadway passage allowed WSDOT to focus on removing the 1.4-mile-long Alaskan Way Viaduct, an aging structure opened in 1953 and deemed susceptible to earthquakes.
Demolition in the tightly packed downtown core takes a delicate touch. With the viaduct hovering over a key utility corridor for Seattle, contractor Kiewit Infrastructure West must pay special attention to ensure the safety of the utilities buried under the viaduct. To do so, they use 4 ft of viaduct rubble as a way to absorb the impact from falling debris, protecting the utilities underneath and helping prevent rubble from splashing out.