Work filling the Battery Street Tunnel with viaduct rubble nearing completion

Posted on Jul 30 2019 10:29 AM

The first phase of filling the Battery Street Tunnel is wrapping up, scheduled to be completed this week. Since the tunnel closed on February 1, crews have been working inside on its decommissioning and filling. Such work included retiring and removing the tunnel’s utilities and mechanical systems, removing hazardous materials and filling the tunnel to about half its height with crushed concrete rubble.

A four-wheeled golf cart sits in the entrance to the Battery Street Tunnel which has been half filled with crushed concrete rubble

Above: A look inside the Battery Street Tunnel, now half-filled with crushed concrete rubble from the viaduct.

For the first phase of filling, crews used processed concrete rubble from demolished pieces of the viaduct, pouring it in from vents in Battery Street above and compacting it down with vibratory rollers. This cycle of pouring and packing continued until the tunnel was filled to about seven feet from its ceiling.

What’s next?

Before moving onto the next phase of filling, crews are spending the rest of this year building utilities in the tunnel. Filling the tunnel provides a unique opportunity to build sewer and electrical infrastructure. Instead of digging into an existing street, crews can layer in vaults, duct banks and sewer lines before filling in the space around them.

Once utility work is complete, scheduled for early 2020, crews will finish filling the tunnel. Phase two entails pouring low-density cellular concrete into the tunnel from the surface. This flowable concrete will fill in the gaps in the interior top of the tunnel. 

Graphic showing both phases of filling the battery street tunnel

The Battery Street Tunnel portion of the project also involves work above ground, including worksite restoration and surface street improvements along Battery Street. Neighbors and travelers in the area can expect some travel or parking lanes to be temporarily closed along Battery Street between Second and Sixth avenues during the upcoming months, with crews typically working one block at a time.

To stay up-to-date on Battery Street Tunnel construction updates (as well as construction and traffic updates for viaduct demolition and Seventh Avenue North construction), join our weekly email list. You may also contact the project via email, viaduct@wsdot.wa.gov, or by calling the 24/7 construction hotline at 1-888-298-5463.

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