Alaskan Way Viaduct 2018-02-05T14:18:11+00:00

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$3.2 billion Seattle project is actually a collection of 32 individual projects that launched in 2010 to replace an outdated section of State Route 99.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.

Toll plan for Seattle tunnel to be released in the spring

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.

January 18th, 2018|

Seattle viaduct demolition: When it will happen and what to expect

Curbed Seattle » With Bertha the tunnel-boring machine’s job complete, the Alaskan Way Viaduct replacement tunnel’s construction is well underway. And with the replacement coming, the viaduct’s days are officially numbered.

August 3rd, 2017|

New delay in Bertha rescue as engineers study sinking soil

December 8th, 2014|

‘The object’: Something deep and mysterious has blocked the world’s biggest tunnel boring machine under Seattle

December 20th, 2013|

Bertha Launch Pits Become Tunnels

ENR Northwest » The launch and exit pits created for tunnel-boring machine Bertha in Seattle are in the last phase of being transformed into parts of the multilevel roadway that replaces the Alaskan Way Viaduct. Here’s how the process works.

October 2nd, 2017|

Video: Bertha’s journey under the streets of Seattle

The Seattle Times » A 360-degree video shot inside the tunnel being built beneath Seattle gives viewers a unique new perspective of what it’s like to bore a 2-mile tube and construct a highway 200 feet underground.

March 10th, 2017|

Bertha veers a few inches off course, stops digging

The Seattle Times » The massive drill has veered a few inches off course.

March 1st, 2017|

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.

July 14th, 2016|

A video of the difficult work of changing Seattle tunnel machine’s cutting tools

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.

July 12th, 2016|

Sinkhole worries loom large as Bertha prepares for dive under viaduct, downtown

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.

April 6th, 2016|

State wants answers before Bertha resumes digging

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.

January 28th, 2016|

Contractors challenge Governor’s order to halt Bertha after sinkhole

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.

January 25th, 2016|

Washington Governor suspends Bertha tunneling after sinkhole

King 5 News » A sinkhole developed near the repair pit shortly after drilling resumed on the new State Route 99 project causing Washington State Governor Inslee to issue a stop work order on the project until the Seattle Tunnel Partners (STP) can guarantee the public’s safety.

January 14th, 2016|

After 2-year breakdown, Bertha begins tunneling again

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.

January 7th, 2016|

Bertha back on the move after 2 years of delays

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.

December 22nd, 2015|

Workers begin preparing soil for Bertha’s restart

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.

October 14th, 2015|

WSDOT sues contractor on Bertha tunnel project

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.

October 9th, 2015|

Crews start moving Bertha’s rebuilt cutter drive back into pit

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.

August 27th, 2015|
Load More Posts