SEATTLE — Contractors will accelerate work to fill in the Battery Street Tunnel as soon as next week, according to the Washington State Department of Transportation.
So far crews have trucked in rubble through the north and south entrances, but they will now dump rubble from the Alaskan Way Viaduct demolition from the top using chutes along Battery Street.
After sections of the viaduct were torn down, they were trucked to Terminal 25 where steel rebar was removed and the concrete was rubblized to about the size of a baseball.
The fill will then be compacted inside the tunnel using a vibratory roll.
It’s expected to take about three months for crews to fill in the tunnel up to about seven feet from the ceiling.
After that low-density cellular concrete will be pumped in from surface vents along Battery Street to finish the job. Mixing that concrete onsite will eliminate 4,000 loads of concrete on surface streets, according to WSDOT.
During construction, people can expect increased noise, dust and vibration on weekdays from 6:30 a.m. to 5:30 p.m. Battery Street will be reduced to one lane on weekdays while crews pour rubble down the chutes into the tunnel but will completely re-open by 3 p.m. each day for the evening commute.
Before it was decommissioned, some groups pushed for the Battery Street Tunnel to be turned into a community amenity, like a park or bus staging area. However, WSDOT says the tunnel is seismically vulnerable, and decommissioning it will allow crews to rebuild three blocks of Seventh Avenue North into a two-way street with four-way intersections and bus lanes.
Filling in the Battery Street Tunnel is all part of the demolition of the viaduct, which began in February and is expected to last about six months.
Crews are currently demolishing the double-decker section between Seneca and Madison streets and a portion east of Victor Steinbruck Park and south of Lenora Streets. Next on tap is the double-decker section between the Seattle Aquarium and Seneca streets.