Video: How viaduct rubble is processed for filling the Battery Street Tunnel
Posted on May 15 2019 2:39 PM
Every day trucks carry viaduct rubble south to Terminal 25 along the Duwamish River for processing. There, rebar is removed, and the concrete crushed into small pieces. The processed rubble is then trucked up to Battery Street to fill the tunnel.
Filling the Battery Street Tunnel from the surface has begun
Work to decommission the aged and seismically vulnerable Battery Street Tunnel continues as crews fill the tunnel from the surface level. Trucks pour processed viaduct concrete rubble into a hopper (a sort of funnel) placed atop the Battery Street Tunnel’s old ventilation grates. The hopper contains water sprayers and rotates as it pours its contents into the tunnel to prevent dust. Inside the tunnel, the rubble falls into piles which crews spread and then compact with a vibratory roller. The fill material will be placed and compacted up to about seven feet from the ceiling.
Placing the crushed concrete will last about three months. The final seven feet of the tunnel’s interior will be filled with a low-density cellular concrete; this work is scheduled to occur in late 2019 and early 2020. See our earlier post for details about work hours.
Once the tunnel is filled, the vents will be removed and sealed up as part of other surface street restoration work on Battery Street scheduled for summer 2020.
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