How crews will fill in Seattle’s Battery Street Tunnel
Lost in all the Alaskan Way Viaduct and tunnel talk is what is going to happen to the Battery Street Tunnel.
There have been some last-minute attempts, that we have talked about before, to save the Battery Street Tunnel. Some believe it would be a waste to simply fill it in.
Advocates have proposed turning it into a park, or a bike and pedestrian through-way. None of that is going to happen. The 64-year-old Battery Street Tunnel will be filled in. A lot of that fill material will be coming from the broken-down concrete of the demolished Alaskan Way Viaduct.
Phil Wallace of demolition contractor Kiewit said they have to remove all the metal rebar first, and then the concrete will head into the Battery Street Tunnel.
“We’re going to take it down to Terminal 25, crush it down to three-inch-minus and put it in the tunnel,” Wallace said.
Three-inch-minus, for those that aren’t in the construction business, means the pieces of concrete will be crushed into chunks that are three-inches across, or less. Wallace said all of that debris will fill the base of the 2,000-foot-long tunnel.
“We’ll bring it up to a 10 foot, plus or minus, level within the tunnel, and then the tunnel from that to the top is filled with what they call a cellular concrete,” he said.
Cellular concrete is a type of concrete and foam mix that is easier to dig-into. It should be good for future needs, should the city want to put utilities through the area.
We don’t have the final timeline for filling-in the Battery Street Tunnel or when it will be finished, and Wallace said they have work to do first.
“There’s a lot of work we need to do in the tunnel before we can place material in there,” he said. “There are a lot of utilities we have to re-route.”
The Battery Street Tunnel will remain open through the three week closure of Highway 99. You will still be able to get on or off at Western Avenue.