The Alaskan Way Viaduct
This $3.2 billion Seattle project is actually a collection of 32 individual projects that launched in 2010 to replace an outdated section of State Route 99. The most famous part is the 2-mile-long tunnel dug by the “Bertha” drill, which started burrowing into the Seattle soil in summer 2013. After a two-year delay to diagnose and repair technical troubles with the drill, Bertha finished tunneling on April 4, 2017. State and local government officials estimate the entire project will be completed in 2023.
KING-TV » The Washington State Transportation Commission is expected to get a progress report Thursday on the upcoming statewide pay-by-mile pilot program, which could eventually be a gas tax replacement. Because there are more highly fuel-efficient cars these days, the state says it needs to find new ways to make up for the lost tax revenue to pay for roads.
The Seattle Times » Watch as the tunnel Crews will stop pumping groundwater from the soil surrounding stranded tunnel-boring machine Bertha, after state surveyors found Sunday that the Alaskan Way Viaduct is sinking in an uneven manner that could lead to damage.boring machine known as Bertha emerges and is disassembled.
‘The object’: Something deep and mysterious has blocked the world’s biggest tunnel boring machine under Seattle
National Post » A secret subterranean heart, tinged with mystery and myth, beats beneath the streets in many of the world’s great cities. Tourists seek out the catacombs of Rome, the sewers of Paris and the subway tunnels of New York. Some people believe a den of interstellar aliens lurks beneath Denver International Airport.
Seattle Post-Intelligencer » Called the Holgate-to-King Street project, WSDOT plans to replace that section of the double-deck highway with two side-by-side roadways that as envisioned, will connect with the planned deep-bore tunnel beneath downtown Seattle, which will replace the central waterfront portion of the aging viaduct.
Video: How a double-deck highway is built inside the Seattle tunnel – with enough concrete to fill 9 football stadiums
GeekWire » The Washington State Department of Transportation (WSDOT) takes viewers on a behind the scenes construction tour of the new double-deck State Route 99 tunnel. WSDOT’s Deputy Administrator explains how the tunnel boring machine, known as Bertha, works to dig through the ground and place concrete rings to form the tunnel wall as she goes. Watch as the tunnel takes shape and construction crews build the framework and pour concrete for the roadway. It is estimated the new tunnel will use enough concrete to fill nine football stadiums. Click here for the video.
GeekWire » Seattle Tunnel Partners (STP) has released a video of construction crews performing routine maintenance on Bertha, the tunnel boring machine, which includes power washing the cutting head and replacing cutting tools that weight 75 pounds each. Bertha is outfitted with 700 cutting tools (or teeth). During this maintenance stop STP has inspected 400 teeth, replacing 25, and remains on schedule to resume digging at the end of July.
The Seattle Times » The Alaskan Way Viaduct was scheduled to be closed for two weeks beginning on April 29 so Bertha, the tunnel boring machine, could work under the existing tunnel and move forward 385 feet. The Alaskan Way Viaduct reopened five days earlier than scheduled, but Bertha still needs to finish boring the remaining 73 feet.
The Seattle Times » In January 2016, a geotechnical expert for the Washington State Department of Transportation (WSDOT) warned officials of possible over excavation and ground loss one day before a sinkhole appeared 110 feet behind the tunnel boring machine’s cutting face. WSDOT and their consulting engineers are concerned about the contractor’s ability to maintain soil consistency, and the potential for additional sinkholes while the tunnel boring machine, known as Bertha, digs under downtown Seattle and the existing Alaskan Way Viaduct.
The Seattle Times » The Seattle Tunnel Partners (STP), the contractor on the Highway 99 tunnel project, submitted a report to Washington state officials to explain why a sinkhole formed near Bertha’s (the tunnel boring machine’s) repair site. In a statement, Governor Inslee said the information provided was insufficient.
The Seattle Times » Seattle Tunnel Partners (STP) disagrees with the stop work order issued by Washington State Governor Inslee. STP contends its response to the sinkhole was appropriate, and believes the risk for additional sinkholes is increased if drilling stops now. This article highlights a few of the findings listed in STP’s root cause analysis, which will be reviewed by a state-selected panel of construction experts.
Associated Press / KomoNews.com » After being stuck for two years, Bertha, the machine boring a tunnel under Seattle, has successfully moved 73 feet and installed 12 concrete tunnel rings. The Seattle Tunnel Partners (STP) and the Washington State Department of Transportation (WSDOT) now expect the project to be completed by April 2018, nearly three years later than originally planned.
The Seattle Times » According to the Washington State Department of Transportation (WSDOT) the tunnel boring machine, Bertha, is finally on the move again after stalling two years ago. The contractors, Seattle Tunnel Partners (STP), plan to resume digging under the Alaskan Way Viaduct in March 2016 after a testing period in January. Repair costs are expected to exceed $143 million, in addition to the existing $1.35 billion contract with STP for the State Route 99 project.
The Seattle Times » The tunnel boring machine, known as Bertha, is almost ready to resume digging. Bertha’s new rotary cutter and soil mixing arms will be tested over the next few weeks. The Seattle Tunnel Partners are injecting grout into the soil and plan to resume digging by November 23, 2015 with construction completion expected by March 2018.
Puget Sound Business Journal » In response to lawsuits by insurance companies, the Washington State Department of Transportation (WSDOT) filed suit against the lead contractor for the Alaskan Way Viaduct tunnel project, nicknamed Bertha. WSDOT is requesting the state court postpone any legal action until the project is completed.
The Seattle Times » The boring machine, nicknamed Bertha, is expected to resume digging by November 2015, two years after she overheated and stalled. Additional teeth, improved seals, and 86 tons of reinforced plates have been added, along with longer arms and fins to loosen the ground as Bertha digs. The Alaskan Way Viaduct is expected to open in March 2018. So far, the Washington State Department of Transportation (WSDOT) has paid $1.04 billion to the Seattle Tunnel Partners (STP) on the $1.35 billion design-build contract, and Bertha’s manufacturer, Hitachi-Zosen, has covered the multi-million dollar repair cost.