Contents tagged with home

  • SR 99 tunnel’s north portal taking shape near the Space Needle

    A few blocks northeast of the Space Needle, crews are building the north portal of the SR 99 tunnel. It’s a huge piece of the overall tunnel project, but it’s largely invisible to the thousands of people that pass by it every day.

    About the only place you can see the north portal taking shape is from the viewing deck of the Space Needle because most of the construction is underground, inside a pit that’s every bit as impressive as the launch pit where Bertha, the SR 99 … more

  • April 3 update: Setting the stage for Bertha’s repairs

    Drivers on SR 99 in Seattle will soon see a noise-blocking wall rise out of the ground near the spot where crews will dig a pit to reach and repair Bertha, the SR 99 tunneling machine. The double-plywood wall, which will be as tall as the lower deck of the Alaskan Way Viaduct, is designed to shield neighbors from construction noise associated with the repairs. It will stretch along the west side of the viaduct between South Jackson and South Main streets. Construction of the wall should take about two weeks.

    Our contractor for the tunnel project, Seattle Tunnel Partners (STP), is still finalizing their repair plan for the machine. What we know so far is that crews will dig a 120-foot-deep pit in front of the machine, which is located about 60 feet below the surface between Jackson and Main. The machine will then tunnel forward into the pit so crews can partially disassemble it and make repairs to the seal system and main bearing. These conceptual drawings illustrate the basic idea.

    Because this is a design-build contract, STP is responsible for developing and implementing the plan to fix the machine and resume tunneling. Schedule and budget impacts of the tunneling stoppage, which began in December 2013, won’t be known until after the plan has been finalized. The contract currently requires STP to open the tunnel to drivers by Jan. 2, 2016.

    Previous updates 

    March 13, 2014 update - Seattle Tunnel Partners submits repair plan, archaeological surveys underway

    Feb. 28, 2014 update - A week in review: Bertha repair plan, ERP’s 2014 report and a viaduct weekend closure reminder

    Feb. 27, 2014 update - How is an early or late tunnel opening addressed in the design-build contract?

    Feb. 25, 2014 update - Ground settlement near the viaduct is safe, expected

    Feb. 21, 2014 update – Seattle Tunnel Partners will dig access shaft to reach tunneling machine

    Click here to see a full archive of progress updates

    — more —
  • Lots to see inside the tunnel launch pit

    You can’t see much from the surface, but there’s a lot of work happening in the launch pit where tunneling started last summer. Last week, Seattle Tunnel Partners removed the giant steel frame that Bertha, the SR 99 tunneling machine, pushed against to start her drive into the tunnel. The frame is now on its way to be recycled.

    Work is also well underway to dismantle the temporary concrete tunnel rings Bertha installed to give her additional leverage at the start of her … more

  • Keeping the Alaskan Way Viaduct safe until the tunnel opens

    We're looking forward to opening the tunnel to traffic and demolishing the Alaskan Way Viaduct. It’s the reason we come to work each day. But until we take down the viaduct, it’s our job to protect it and keep it safely open to drivers.

    And so this weekend, as they do four times every year, WSDOT crews will inspect the viaduct. They’ll start by closing the structure to traffic on Saturday and Sunday. Then they’ll begin a methodical weekend of work measuring … more

  • Building a better transportation system

    The Washington State Department of Transportation is working to build a safer, more durable, effective transportation system for our citizens. All across the state – from Bellingham to Vancouver, Forks to Spokane – we manage hundreds of important transportation projects each year to upgrade or replace aging roads and bridges, increase capacity for carrying people and freight, and create more environmentally sustainable travel options for the public.

    You’ve been hearing … more

  • The beauty of barging

    On Nov. 23, crews started barging soil from the tunnel dig site to a disposal facility near Port Ludlow. Adding barges to the fleet of trucks hauling away soil has greatly improved the speed and efficiency of the tunneling operation.

    The reason for that is simple: Bertha is moving a lot of soil – soil that has to be taken away to make room for more soil. If crews removing it can't keep up with Bertha, the bin where the soil is stored gets full and the machine has to slow down. … more

  • Tunneling in Seattle started long before Bertha

    Seattleites were digging tunnels long before Bertha, the SR 99 tunneling machine, came along. Folks started transforming subterranean Seattle in 1894, with construction of a sewer tunnel not far from the SR 99 tunnel’s north portal construction site. Since then the city has seen – or not seen, as the case may be – construction of more than 40 miles worth of tunnels.

    Last month marked the 109th anniversary of the historic breakthrough on the Great Northern Tunnel, which … more

  • Happy Birthday, Bertha Knight Landes – you were one of a kind

    Saturday, Oct. 19, marks the 145th birthday of Bertha Knight Landes, after whom the SR 99 tunneling machine was named.

    Ms. Landes didn’t dig any tunnels, but there’s no question she broke ground. Elected mayor of Seattle in 1926, she was the first woman to lead a major American city. During her two years in office she battled bootleggers, cleaned up corruption in city government and put the city’s finances in order.

    She was active outside of politics, too, playing … more

  • Bertha breaks 200-foot mark

    Bertha, the SR 99 tunneling machine, has passed the 200-foot mark as she continues her dig toward the north end of downtown Seattle.

    By the end of her shift on Oct. 8, Bertha had traveled a total of 209 feet and the top of her cutterhead was about 20 feet below the surface. She averaged nearly 14 feet of digging per day over the past week.

    Bertha is still making her way through fill soil that crews have injected with grout to provide additional strength. She’ll pass into … more

  • Desperately seeking soil: As we expected, Bertha is off to a slow (but good) start

    After slogging through 15 feet of concrete, Bertha gets a taste of the good stuff – but why did it take so long?

    Engineers depend on math. It is the thing that, more than any building material, gives shape to their designs. Want proof that what you’re building matches the design? Check the plans, do the math.

    But when it comes to tracking the progress of Bertha, the SR 99 tunneling machine, you can’t rely on an equation. Yes, we told you that Bertha would average 6 … more