West Seattle, Washington
After three weeks of tunnel-machine stopdown, still no restart plan, but WSDOT is just out with another project update, saying that work is about to start to fix pier damage done in the process of barging what was being dug out. Also: No new sinking – instead, some “upward movement”:
Seattle Tunnel Partners is set to repair damage that occurred at Terminal 46 during the Jan. 12 barging incident. STP will remove 22 damaged timber piles from the pier at the northern edge of Terminal 46 and replace them with temporary piles. Work is expected to begin in the coming days and could take up to 10 days to complete, according to STP.
WSDOT and STP continue to work together to address the “suspension for cause” that halted tunneling and barging operations on Jan. 14. STP crews are prepared to remove excavated soil by truck if tunneling resumes before the pier at Terminal 46 is repaired.
You can watch the pier repairs unfold on our construction camera. The labels on the image (above) call out some of the key elements you’ll see in the regularly updated time-lapse images.
Ground monitoring update
It’s been approximately two weeks since Seattle Tunnel Partners turned off the deep dewatering wells that were used to control groundwater near the access pit. There was some upward ground movement in the days following the shut-off, but the movement quickly stabilized. The degree of movement tapers off over several city blocks and is uniform in nature, which poses little to no risk of damage to the Alaskan Way Viaduct or buildings.
Some ground survey points in the vicinity of the pit show as much as 3/5 inch of upward movement since Jan. 22 when STP began turning off the wells. Some of the Alaskan Way Viaduct columns and buildings show similar movement.
STP had additional, shallower dewatering wells in operation during the tunneling machine repair effort. They turned off the final two shallow wells on Thursday evening. STP and WSDOT continue to monitor the ground, buildings, utilities and the viaduct.
When the digging stopped last month, WSDOT says, 1,280 feet of tunneling was complete, of the expected 9,270 feet.
Two weeks after WSDOT told its Highway 99 tunnel contractor to stop digging, it’s still not ready to give the green light for digging to resume, according to this update late today:
Last week, Seattle Tunnel Partners submitted their analysis of recent incidents on the SR 99 Tunnel Project. WSDOT and their tunnel experts determined STP’s analysis did not sufficiently address the cause of these incidents or specify how they would prevent them from occurring in the future.
(WSDOT graphic from January 13th)
WSDOT has notified the contractor that in order to lift the suspension for cause, STP must confirm that:
· The tunneling machine is operating as intended and meets the design-build contract’s technical requirements.
· All necessary training for staff on the tunneling machine is complete.
· The tunneling work plan is updated to address the issues that led to the sinkhole.
· Processes are in place to ensure STP’s tunneling work plan is followed.
· STP updates its quality program to ensure key quality program managers are involved in all tunneling activities.
It is STP’s responsibility to determine how to address these issues and ensure they are in compliance with the technical requirements of the contract. This section of the tunnel drive was designed to be a test section for operation of the tunneling machine. With approximately 250 feet of tunneling prior to reaching the next planned maintenance stop, demonstration of these steps is critical.
No indication of exactly how this is affecting the schedule aside from obviously pushing it back at least two weeks – including the expected Viaduct closure when the tunnel machine goes beneath it, previously expected to happen in March.
Just in, an update from WSDOT, following up on its order last week telling its contractor to stop Highway 99 tunneling because of recent incidents including a sinkhole and trouble with the barge that was receiving excavated material:
Last week, WSDOT notified Seattle Tunnel Partners that they must “suspend for cause” tunneling operations involving the tunneling machine and the loading of barges. WSDOT took this step to ensure STP’s work can proceed safely following recent incidents on the SR 99 Tunnel Project. Safety remains the top priority for the project and we can’t speculate on when tunneling will resume.
In response to the suspension for cause, STP has informed WSDOT they are analyzing the recent incidents and intend to provide follow-up information this week. WSDOT, in consultation with its tunneling experts, will then review the information and determine the appropriate next steps.
STP has notified WSDOT they plan to sequentially turn off the deep dewatering wells soon. These wells, which have been used to control groundwater, were previously scheduled to be shut off when the tunneling machine reaches the next planned maintenance stop. With tunneling operations currently on hold, STP has determined that there is an opportunity to turn off the wells earlier than planned. We will continue to monitor movement of the ground, structures, utilities and the viaduct. Additional information about our ground monitoring program can be found here.
ORIGINAL REPORT, 12:13 PM: Just in from WSDOT:
The Alaskan Way Viaduct Replacement Program (WSDOT) is in the process of notifying Seattle Tunnel Partners to suspend tunneling operations involving the tunnel boring machine, a “Suspension for Cause” in contractual terms, until such time as WSDOT lifts the suspension in writing. We will provide a copy of the letter after it is delivered to STP.
The following is a statement from Secretary of Transportation Lynn Peterson:
“In light of recent incidents on the SR 99 Tunnel Project, WSDOT is notifying the contractor that they must suspend tunneling work for cause. I share the Governor’s concern for public safety and we want to ensure that the contractor has the right protocols in place to proceed with their work safely.
We are asking that the contractor complete root cause analysis and take the appropriate steps to ensure that incidents, such as the sinkhole near the repair pit, do not occur again. STP will not be allowed to resume tunneling until their analysis and work plans meet the satisfaction of our experts.
I want to remind everyone that replacing the viaduct is critical to public safety. We have conducted surveys of the viaduct and no movement has been observed; surveys will continue. The tunneling work must proceed, but it must proceed safely.”
This week alone, besides the 35′ x 20′ x 15′ sinkhole, there also was trouble with the barge being used for excavation spoils. WSDOT stresses, however, that other work – such as the Highway 99 lane closures starting next week for tunnel-related sign installation – goes on. More as we get it. Per WSDOT’s “Follow Bertha” page, as of Tuesday, 1,280 feet of tunneling had been completed, of 9,270 feet in all.
P.S. Checking our archives – available via Google cache until our full site is up – we note that yesterday was the seventh anniversary of the announcement by then-Gov. Gregoire, then-Mayor Nickels, and then-County Executive Sims that a deep-bore tunnel had been chosen to replace the Alaskan Way Viaduct.
4:02 PM UPDATE: As promised, WSDOT has made public the letter sent to Seattle Tunnel Partners. You can read it in its entirety here. Here’s what’s at the heart of it:
WSDOT has determined that STP has failed to correct conditions unsafe for the Project personnel or general public, and failed to comply with Governmental Approvals, Law, or otherwise carry out the requirements of the Contract Documents. Therefore, WSDOT has the authority to suspend work for cause, pursuant to Contract Sections 14.2 (a) and 14.2(b) and Technical Requirements Section 220.127.116.11.5.
On the night of January 12, 2016, a sinkhole was detected over the tunnel. The full extent of ground loss is not yet determined and settlement is increasing. STP has yet to provide a detailed analysis of the cause of the observed ground settlement, or a plan for modifying tunneling operations to ensure positive ground control at all stages of tunneling (TR 2.32), and to prevent settlement outside of tolerance in the future (see TR 2.52).
On Tuesday January 12, 201 6, STP’s barge filling operation resulted in a barge listing beyond STP’s control. As a result the barge was either let go or broke free from the pier, spilling tunnel spoils into Elliott Bay, and drifted out of control damaging both Terminal 46 and Pier 48. These events created an unpermitted spill of material and posed a hazard to project personnel and the public.
WSDOT requests a meeting with STP within 24 hours to address this matter.
4:10 PM: More news today from WSDOT, the day after the Highway 99 tunneling machine had to stop while they sorted out a problem with the barge that was collecting excavation spoils. The barge problem isn’t fixed yet, but they brought in some trucks, and digging resumed. Then came a sinkhole. Here’s the WSDOT update sent this afternoon:
Seattle Tunnel Partners resumed mining Tuesday evening, using trucks to remove excavated material while they continued working to resolve an issue with a soil-removal barge. STP crews resumed excavation at 7 p.m. Tuesday.
Approximately two hours later, a sinkhole developed within STP’s work zone near South Main Street, about 35 feet north of the access pit. It is located more than 100 feet south of the cutterhead’s current location, in ground that crews mined through last week. STP filled the sinkhole overnight with 250 cubic yards of concrete.
This section of the tunnel drive is protected by an underground wall built by STP before tunneling. The wall was designed to isolate ground movement and protect the nearby Alaskan Way Viaduct. A manual survey of the viaduct conducted after the sinkhole developed found no movement. WSDOT and STP will continue surveying and monitoring the ground, viaduct, utilities and other structures.
The cause of the sinkhole is still under investigation. STP is analyzing the portion of the tunnel that crews have excavated since mining resumed. There is no indication that any other locations have experienced ground loss.
STP is reviewing their daily operations as a result of this incident. Immediately they will enhance monitoring protocols by requiring crews to manually verify the amount of soil removed during excavation of each ring.
The protocols STP outlined to enhance monitoring were used in the first 1,000 feet of tunneling and WSDOT is disappointed they were not used when STP restarted tunneling in December 2015. STP has several hundred feet of mining before they reach the next planned maintenance stop. Before leaving the maintenance stop, STP’s operational protocols will undergo an additional review by an expert to assure public safety.
STP has temporarily stopped mining to prepare the muck storage pit to receive excavated material. They plan to resume tunneling this week using trucks to remove excavated material. …
Safety remains our top priority as we work to replace the seismically vulnerable Alaskan Way Viaduct. We expect STP to further investigate this incident and take the appropriate corrective action as they continue to build this important project.
ADDED 6:31 PM: We asked WSDOT’s project spokesperson Laura Newborn about the sinkhole’s size: “According to Chris Dixon, the dimensions of the sinkhole were 35 feet long, 20 feet wide and 15 feet deep.”
WSDOT posted that miscellaneous tunneling-machine-operations-in-progress video this afternoon to go along with the news that the machine is out of the “access pit” and “is now tunneling in Seattle soil after breaking through the access pit wall late Wednesday. Seattle Tunnel Partners has mined 73 feet and installed 12 concrete tunnel rings since Bertha first moved forward in the pit on Dec. 22. More mining is scheduled to occur this week. Now approaching South Main Street, near Pier 48, Bertha is digging well below the area’s notorious fill soil. The top of the machine is approximately 80 feet below the surface in a mixture of glacially compacted material.” That’s from the newest WSDOT update, which you can read in its entirety here. WSDOT also has set up a new tunnel-machine-tracking page. If all goes well from here, they’re still heading toward a March closure of the Alaskan Way Viaduct “for about two weeks” while tunneling under the structure. Speaking of The Viaduct, WSDOT adds that crews are starting to take apart the big red crane that’s been alongside it during the tunneling-machine-repair process.
Six and a half feet and one more ring for the Highway 99 tunnel machine, WSDOT announced late today. That puts its cutterhead close to the north side of the access pit, where it will have to go through a 15-foot concrete wall: “Once beyond the wall, crews will begin tunneling through native soils that will serve as the next stage of STP’s testing process. This section of the tunnel route includes an underground wall that was built to protect the Alaskan Way Viaduct while crews continue to test the machine.” Read the rest of the update here, including details of how the removal of excavated material has resumed.
(Click image for larger view)
Long before we get to that potential closure of the Alaskan Way Viaduct when the tunneling machine travels under it, Highway 99 has long-running lane closures coming up north of downtown – to build “four large sign foundations for the future tunnel” – and WSDOT really, really, really wants to make sure you know those closures are set to start two weeks from today, on Monday, January 18th. WSDOT spokesperson Laura Newborn emphasizes, “What’s most important for drivers and commuters to know is that while two lanes in each direction of SR 99 between Highland Drive and the Aurora Bridge will remain OPEN during peak commute hours, buses and vehicles will share the bus-only lane.” Read on for the full reminder from WSDOT:
With the Highway 99 tunneling machine restarting, WSDOT has been loudly banging the warning drum about the anticipated two-week Alaskan Way Viaduct closure, once the machine starts digging beneath it. Remember, we survived a one-week closure four years ago during the demolition of its southern mile in October 2011. As part of that, the West Seattle Water Taxi got heavier usage than ever:
(WSB photos, October 2011)
Some runs were at capacity. But this time around, the run will have a bigger new boat, as the M/V Doc Maynard is scheduled to finally take over next month. We asked Rochelle Ogershok from the county Transportation Department what’s being discussed so far to maximize the Water Taxi during the anticipated closure, potentially as soon as March, and that was the first thing she mentioned:
Specific to West Seattle the following plans are:
Vessel Schedule and capacity: The Winter Water Taxi schedule will be operated with increased capacity on commute hour sailings. Doc Maynard has a capacity of 278 passengers as compared to 147 passengers on Spirit of Kingston. This is an increased capacity of 786 passengers in the morning and 917 in the afternoon.
Water Taxi Dock Access: The Marine Division is coordinating with the City of Seattle on parking options along Harbor Ave and Don Armeni boat launch similar to what happened during the 2011 closure. Those actions included:
*Additional all-day street parking along Harbor Ave.
*Additional parking at Don Armeni Park
We are also investigating the feasibility of operating larger shuttles to accommodate more passengers.
Again, specific plans have not been finalized – we will continue to coordinate with WSDOT and City of Seattle on closure details and will share with riders as this information becomes available.
The extra spaces at Don Armeni went fast during the October 2011 closure:
Meantime, the state is promising ongoing information about the expected closure via this WSDOT webpage. The real test of the tunneling machine will come when it resumes work early in the New Year.
Another Highway 99 tunneling-machine update from WSDOT before the holiday: The video above shows the machine building the tunnel’s 160th ring. (The music you hear isn’t a holiday feature, WSDOT says, explaining in the YouTube caption that it’s a safety alert.) The full online update says in part:
… In all, Bertha has excavated 8 feet of tunnel since STP restarted the machine early Tuesday. STP crews – which have been working long hours in the weeks leading up to the machine’s restart – will take a break over the holidays before resuming tunneling in the first week of January.
When work resumes, crews will mine through the concrete wall of the access pit and into the native soils that will serve as the next stage of STP’s testing process. This section of the tunnel route – like the 1,091 feet that came before it – is protected by underground walls that were built to hold the ground in place while crews continue to test the machine.
Bertha will mine toward an underground block of concrete approximately 450 feet north of the access pit. This area is the third and final protected maintenance stop, or safe haven, that STP built prior to the start of tunneling. According to the STP’s most recent schedule, the machine will spend up to one month at the safe haven while crews perform maintenance and make final adjustments before tunneling beneath the Alaskan Way Viaduct. …
The update also includes a reminder of the two-weeks-or-so Viaduct closure planned when that happens.
The Highway 99 tunneling machine is out of sight but by no means out of mind.
WSDOT announced this morning that the machine has started moving forward in the “access pit” where its cutterhead was accessed for repairs (now backfilled, as shown in the WSDOT time-lapse video above). Here’s the full text of its latest news release (and note the reminder of a Viaduct closure in a few months, if all stays on the current schedule):
The State Route 99 tunneling machine entered its next phase of testing early Tuesday, Dec. 22, near Pier 48, moving forward and installing a tunnel ring at the bottom of the 120-foot-deep pit crews built to access and repair the machine. Seattle Tunnel Partners, the Washington State Department of Transportation’s design-build contractor for the tunnel project, plans to tunnel a short distance further in the access pit tunnel before giving crews a break for the holidays.
“Testing the machine in the conditions it will face during the rest of the tunnel drive is a critical part of our work to resume full-production mining,” said Chris Dixon, Seattle Tunnel Partners project manager. “The next several hundred feet of excavation will give us the information we need to make final adjustments before we tunnel beneath the viaduct and downtown.”
After the new year, STP plans to mine out of the access pit toward a planned maintenance stop 450 feet to the north. Along the way crews will mine slowly while installing tunnel rings and continuing to run tests. When the machine reaches the maintenance stop – essentially an underground block of concrete just south of Colman Dock – crews will perform maintenance and make final adjustments before diving beneath the viaduct.
Tunneling under the viaduct will require a full closure of SR 99 through downtown for approximately two weeks. The contractor’s latest projections show that the closure will occur in March, but the actual closure date will depend on Bertha’s progress and the state cannot verify the contractor’s schedule.
STP and Bertha’s manufacturer, Hitachi Zosen, are responsible for the repair effort, including the schedule. While the machine was under repair, STP continued essential work at the future tunnel portals, including construction of ramp and highway connections, and the buildings that will house tunnel operations.
STP crews halted tunneling in December 2013 after the machine overheated. After an investigation, they discovered damage to the seal system and determined it needed to be replaced along with the main bearing. The cause of the damage has not been determined. Responsibility for costs associated with the delay will be determined through the process outlined in the tunnel contract.
“Moving the tunneling machine forward in the access pit is the next step in STP’s testing program,” said Todd Trepanier, WSDOT’s administrator for the viaduct program. “WSDOT will continue to protect taxpayers as we work with STP to complete the project.”
Another update from WSDOT this afternoon, as its contractor Seattle Tunnel Partners approaches the date on which it has said it hopes to restart the Highway 99 tunneling machine – next Wednesday:
Seattle Tunnel Partners has spent much of the week backfilling the SR 99 tunnel access pit. By Friday, only part of the machine’s shield and cutterhead were visible from our time-lapse camera. Crews stopped backfilling on Wednesday afternoon to repair a mixing arm that broke off inside the machine during testing of the cutterhead. Backfilling has since resumed and will continue over the weekend.
STP has indicated they may fill the remainder of the pit with a concrete-sand mixture in addition to material removed during excavation. Using the concrete-sand mixture – rather than sand and soil, as STP previously planned – could reduce the time it will take to complete backfilling. Additionally, the deep dewatering wells that have been used to control groundwater in the pit may be turned off sometime in January. STP previously planned to turn them off this month.
STP has told us they plan to move the SR 99 tunneling machine forward by Dec. 23, the date shown in their most recent schedule. As part of their testing program, STP intends to tunnel forward a short distance in the pit before taking a break for the holidays. After the holidays, STP plans to mine out of the access pit toward a planned maintenance stop approximately 450 feet to the north. Along the way crews will mine forward and install tunnel rings while continuing to run tests.
The state cannot verify the contractor’s schedule, but we will continue to provide updates as STP’s work progresses.
Reminding you again – Highway 99 from the Battery Street Tunnel north to Valley Street (lower Queen Anne) will be closed both ways overnight tonight, with other closures ahead, as part of the project.
(Video clip updated late Monday by WSDOT, so we’ve substituted the new “extended” one)
According to an update this morning from WSDOT, the newest schedule from its contractor Seattle Tunnel Partners still says the tunneling machine is expected to start up again next week, two days before Christmas. (WSDOT, meantime, reiterates that it “cannot verify” the schedule.) Meantime, it’s also published the video clip you see above, showing one of the final steps in access-pit preparation before the machine can get going again – backfilling with sand, which started yesterday and is expected to continue all week. This and other prep steps are all detailed, with graphics, on WSDOT’s project website. It’s now been more than two years before the machine overheated and stopped tunneling.
(Six WS-relevant views; more cams on the WSB Traffic page)
Good morning! New weather alert overnight – now a “wind advisory” is in effect until 3 pm (read it here). And after a rainy night, you’re going to find trouble spots like the “big bad puddle” at Fauntleroy/Raymond, as tweeted by Megan:
UPCOMING 99 CLOSURES: As announced by WSDOT on Monday. They all involve the Battery Street Tunnel *northward* but still could affect traffic between the tunnel and bridge, so here’s the heads-up:
Full closure Dec. 18-19
During this closure, contractor crews working for the Washington State Department of Transportation will set up a work zone between the northbound and southbound SR 99 lanes near Harrison Street in order to build the permanent median barrier.
SR 99/Aurora Avenue North will be closed between the south end of the Battery Street Tunnel and Valley Street:
Northbound lanes: Closed from 9 p.m. Friday, Dec. 18 to 5 p.m. Saturday, Dec. 19
Southbound lanes: Closed from 9 p.m. Friday, Dec. 18 to 7 a.m. Saturday, Dec. 19. One southbound lane will remain closed until 1 p.m. Saturday, Dec. 19
Lane closures Dec. 14-22
Additionally, crews installing a variable message sign may close one southbound lane of SR 99 between Roy and Mercer streets from 8 p.m. to 6 a.m. nightly, Monday, Dec. 14 through Thursday, Dec. 17 and Monday, Dec. 21 through Tuesday, Dec. 22.
Long-term lane closures beginning mid-January
Contractor crews will install the foundations for new overhead traffic signs on SR 99/Aurora Avenue North between Highland Drive and the Aurora Bridge. One lane in each direction will be closed around the clock for approximately seven weeks. An additional lane will be closed at night when there is less traffic on the road and on some weekends to provide additional work zone for the contractor. One lane will remain open during this work.
8:10 AM: We’ve been out checking on other perennial water-over-road trouble spots, such as W. Marginal Way SW – so far, nothing major. But if the forecast heavier rain arrives this afternoon, that could change.
8:53 AM: Just got a text about water over Delridge by Orchard/Myrtle. Off to check.
9:03 AM: It’s cleared – aside from a sizable curbside puddle by the northbound Delridge bus stop north of Orchard.
Survey crews detect between 1/4 and 1/2 inch of additional settlement between University Street and south of Seneca Street since the last inspection. The settlement is uniform in nature. Inspectors also note some additional cracking on columns and girders in the same general area, along with up to 1/2 millimeter widening of a few existing cracks. No additional repair work is necessary.
We know what you’re going to ask – here’s how WSDOT answers it: “It’s important to note that not all settlement is significant. In the case of the viaduct, no single number represents an acceptable level of settlement.” Bottom line, WSDOT says: “The viaduct remains vulnerable to earthquakes but remains safe for everyday use.” (In case you missed it, here’s the latest tunnel-machine update, published here Thursday.)
The state is circulating an update on the Highway 99 tunnel project this afternoon, saying some components are being tested, and the contractor is still working toward restarting tunneling right before Christmas:
Seattle Tunnel Partners and manufacturer Hitachi Zosen have begun testing components of the SR 99 tunneling machine as they prepare to resume mining. A few initial tests were performed last week, and several others are slated to occur in the coming weeks.
7:35 AM: Reminder: Highway 99 is closed again today, between the West Seattle Bridge and the Battery Street Tunnel, as state crews continue its twice-annual inspection, along with some maintenance work. It’s scheduled to continue until 6 pm, but we’ll update if we get word it’s over earlier.
1:10 PM: It indeed reopened early! Inspection results will be available later this week.
8:45 AM: Just a note to remind you that Highway 99 is closed between the West Seattle Bridge and the Battery Street Tunnel until 6 pm, and scheduled to be closed 6 am-6 pm again tomorrow, for its twice-a-year inspection, plus some maintenance work.
5:29 PM: David points out that 99 is open again, with vehicles (as you can see above) going both ways.
Tunnel update just in from WSDOT: The newest monthly construction schedule from its contractor, Seattle Tunnel Partners, has slid another month. If this one holds, the tunnel machine will resume work on December 23rd, and if all goes well, the tunnel would open in April 2018. Read WSDOT’s update in full – including what’s happening near the access pit along the Viaduct – by going here.
10:11 PM: If you’re heading out – or back this way – via Highway 99, be aware the Battery Street Tunnel is closed both ways again. Haven’t heard yet if it’s the recurring sprinkler malfunction or something else.
11:42 PM: After about an hour and a half, the tunnel is open again. Still no explanation.
(Added: Image from webcam over tunnel-machine access pit tonight)
No hint of this just two days earlier, when WSDOT released a video update on the Highway 99 tunnel-machine repairs, hours before its quarterly stakeholders meeting, but, late today, the state sent out a very different update, saying it’s suing its contractor:
WSDOT is committed to working with Seattle Tunnel Partners (STP) to complete the SR 99 Tunnel Project.
We are also committed to protecting taxpayers.
Today, WSDOT filed a lawsuit against STP in King County Superior Court. This filing was prompted by recent court filings by STP and their insurance companies. Filing this lawsuit ensures WSDOT will have a right to make legal claims in the future. This lawsuit does not prevent STP from pursuing claims under the terms of the design-build contract.
Taking action to preserve WSDOT’s rights in court was a necessary step. Our focus remains on completing the project, and removing the seismically vulnerable Alaskan Way Viaduct. We intend to ask for a stay of WSDOT’s lawsuit until the project is completed and asked STP to join us in this request.
This delay in the lawsuit will allow for work on the SR 99 Tunnel Project to be completed before litigation takes place.
The intent of today’s action is simple: protect the interests of Washington taxpayers.
There will be no further statements on this legal matter.
While WSDOT provided the case number – 15-2-24943-6 – we checked the online files, and no documents are available there yet, just “Case Title: Washington State Department of Transportation vs Seattle Tunnel Partners” on the page. We’ll keep checking.
This follows news earlier this week, first reported by the Puget Sound Business Journal, that WSDOT has told insurers it expects costs to rise more than $78 million because of the tunnel-machine trouble. That in turn came out as part of another lawsuit, one filed in New York state by insurers against STP, which says it’s hoping to get the machine going again in November, almost two years after its underground breakdown.
From today’s quarterly meeting of the Alaskan Way Viaduct Stakeholders meeting:
The dates are set for this year’s semiannual AWV inspection closure – scheduled for Halloween weekend, 6 am-6 pm on Saturday, October 31st, and again on Sunday, November 1st. The Viaduct will be closed both ways between the West Seattle Bridge and Battery Street Tunnel. WSDOT said at this afternoon’s meeting that besides the inspection, they’ll do some maintenance as usual – in particular, fire-suppression systems in the BSTunnel need some work.
Also at the meeting, WSDOT played the video that we featured here earlier in the day, showing what’s been happening with the tunneling machine as work continues to get it ready to start tunneling again later this year. The Viaduct closure that’s expected when the machine goes beneath the structure could last up to two weeks. Assuming everything goes as currently projected, the machine will stop in a long-planned “safe zone” just outside the edge of the structure, so it can get a checkup to see how it’s doing after what would be the first few weeks of digging.