Sensing boulders before they become a headache

MudHoney’s cutterhead is lowered into the Ballard shaft in April 2021.

Tunnel boring machines are designed to dig through all sorts of ground, and MudHoney is no exception. Even though sand and gravel are very abrasive and can quickly wear down the cutterhead, the biggest challenge for MudHoney is large cobbles and boulders – pieces of rock ranging from 8 inches to 3 feet or more. These boulders are made of very hard rock like granite and can bend or break off cutting tools. When boulders are expected, MudHoney’s operators will usually slow down the rotation of the cutterhead and increase the thrust to allow the cutting discs to break the boulder into smaller pieces that can pass through the machine.

In addition to using a laser system to stay on course, MudHoney also uses a brand new AI (Artificial intelligence) system from the Colorado School of Mines to detect boulders before running into them. The system measures vibrations that indicate where there might be a boulder in the path ahead.

MudHoney’s operators use the vibration data with other surveying information to get a full picture of MudHoney’s underground path. Knowing where boulders are means we can adjust the speed, thrust, and other variables. Making these adjustments can reduce overall wear on the cutterhead tools (pictured above).

Take a look at our Flickr albums to stay updated on the most recent construction activities, including progress on the Wallingford shaft and a look inside the storage tunnel!

Ballard & MudHoney

After a planned pause, MudHoney, our 18-ft diameter tunnel boring machine, has tunneled 500 feet since resuming tunneling in early February. We have now tunneled a total of 1400 feet! During tunneling activities, you should anticipate:

• Truck deliveries of concrete segments and MudHoney equipment
• Tunneling activities
• Nighttime segment deliveries and tunnel spoils being hauled off
• Noise and vibrations typical of a construction site

Crews are working 24 hours a day, 6 days a week and will continue until MudHoney reaches Wallingford by early 2023. Sunday work may also occur.

Ground monitoring is ongoing along the tunnel alignment and is done from both inside MudHoney and on the surface.

East Ballard

Excavation work for underground mechanical and electrical vaults on NW 45th St is currently suspended due to the concrete strike. During this time, you can expect:

• NW 45th St closed to traffic; vehicles must detour onto NW 46th St
• Burke-Gilman Trail users remain detoured to the north side of NW 45th St through 2022. Please follow all detour guidance on site. For safety, bicyclists should either dismount or cross train tracks at a 90-degree angle. Please use extra caution in wet weather as ramps may be slippery.

Fremont

We anticipate wrapping up jet grouting this week. Lane reductions on Leary Way NW, between 1st Ave NW and NW 39th St, will be in place for another few weeks as we restore the site. Once the concrete strike is over, there will be intermittent utility work in Leary Way that will require short term traffic revisions and lane reductions.

During this time, you should anticipate:

• Lane reductions on Leary Way NW through late March 2022
• Excavators working on-site for utility installation work
• Truck traffic on Leary Way NW as trucks bring and remove materials to and from the site
• NW 36th St between Leary Way NW and 3rd Ave NW closed (through remainder of the project)
• Pedestrian detours on Leary Way NW, please follow all detour guidance on site
• Generators running during work hours to power equipment
• 2nd Ave NW, between Leary Way NW and NW Canal St, closed to vehicle and pedestrian traffic for sewer and diversion structure work at least through the end of 2022
• NW Canal St is open to two-way traffic to allow access during this closure. Please do not park at the west end of NW Canal St to allow two-way traffic to turn around at the closure
• Noise and vibrations typical of a construction site

Regular work hours will be Monday through Friday, from 7 am to 5 pm. Night and weekend work may occur.

Wallingford

Crews continue working on the shaft liner wall and preparing for MudHoney’s arrival. For the next couple of weeks, crews will install steel reinforcement and timber formwork for the lower part of the shaft lining wall. Once this work is complete, we will suspend construction activities at this location until the concrete strike has been resolved.

During this work, you should anticipate:

• Trucks coming in and out of the site to deliver reinforcing steel and formwork materials
• Noise and vibrations typical of a construction site

Regular work hours will be Monday through Friday, from 7 am to 5 pm.

Queen Anne

Crews have nearly completed the installation of temporary shoring. Work is now suspended until the concrete strike is resolved.

During this time, you should anticipate:

• Trucks coming in and out of the site
• Noise and vibrations typical of a construction site
• The West Ewing Mini Park parking lot to remain closed through mid-2023
• A localized Ship Canal Trail detour at least through summer 2022 (see map)

Regular work hours will be Monday through Friday, from 7 am to 5 pm. Night and weekend work may occur.

Contact us

Please email SPU_ShipCanalProject@seattle.gov with questions or comments or call our hotline at (206) 701-0233. You can also find information online at spushipcanal.participate.online/. To support the community during active tunneling, we have changed our hotline hours to 24 hours a day, Monday through Friday.

Construction Safety is Everyone’s Job Check out some top safety tips at www.seattle.gov/utilities/constructionsafety

Have you signed up for AlertSeattle?     AlertSeattle is the official emergency notification system used by the City of Seattle to communicate with city residents during emergencies. Sign up now to receive free alerts from the City via text message, email, voice message or social media. To sign-up for AlertSeattle To update your existing AlertSeattle preferences, access your account Click here for more information

Visit our website