A Safety Reminder from Puget Sound Energy

gasleakDear residents and businesses of Pioneer Square:
​​

It’s always a good thing to know what natural gas smells like and what to do if you suspect a leak. That’s why PSE regularly sponsors public service announcements regarding gas safety. With the recent reports of ground settlement in some areas of Pioneer Square, which could affect underground utilities, we’d like to remind you of some basic safety tips and tell you what we’re doing to ensure the safety of the natural gas system in the neighborhood.

PSE regularly inspects the pipes, meters and other equipment that bring natural gas to the region. As a precaution, we have increased the frequency of these inspections in Pioneer Square. These inspections have not shown any signs of damage or increased incidence of gas leaks.

In addition, as part of the tunnel project, we have increased the resiliency of our gas system in areas above the tunnel route by retrofitting or rebuilding gas pipes and connections that might be affected by ground settlement.

If you should ever smell the rotten egg or sulfur-like odor of natural gas, leave the building immediately and call PSE or 911.

  • Don’t do anything inside the building, including making a phone call, that could cause a spark.
  • If you notice the odor outside, move upwind of the odor and call PSE or 911. Other signs of a leak include hissing, bubbles rising in a puddle, and dead vegetation in unexpected places.
  • PSE will dispatch a technician immediately, at no cost, to investigate.

For more safety tips and to smell the odor of natural gas, please see our natural gas safety brochure, which includes a “scratch and sniff” feature. Click here to request a brochure.

If you have questions, please contact naturalgas@pse.com.

 

Respectfully,

Charlie Gadzik
Customer Safety Communications Manager
Puget Sound Energy

Tunnel Project Update

BerthaWSDOT and Seattle Tunnel Partners conducted additional survey work early Sunday morning (12/7/2014) to further assess the amount and extent of settlement that recently occurred on and near the Alaskan Way Viaduct.

Some of the data was inconclusive and analysis is still underway; however, WSDOT observed that a small amount of differential settlement is occurring near the access pit. Differential settlement is when the ground settles unevenly over an area. When the ground settles evenly or uniformly over an area, there is less risk of damage.

The additional survey work did not find that the differential settlement has caused any new damage to the viaduct nor have we observed any damage to buildings or utilities in the surrounding area. On-the-ground surveys will continue this week by historic architects and structural engineers.

Public safety is our top priority and while we have not seen any damage, Seattle Tunnel Partners is taking the prudent step to stop dewatering. The contractor will work with its geostructural designer to stop the dewatering in a deliberate manner in order to ensure worker safety and the structural integrity of the access pit and surrounding structures.

Data analysis, collection and monitoring will continue and we will provide updates as we have new information to share.

Alaskan Way Viaduct Replacement Program News – August 2014

BerthaTopics:

Bertha update – Construction of the access pit’s underground walls will continue through August

Earlier this week, Seattle Tunnel Partners notified us that building the underground walls of the circular pit (pdf 2.5 Mb) crews will use to access and repair the SR 99 tunneling machine will continue through August. While this date is later than anticipated, STP reports that tunneling is still expected to resume as scheduled in March 2015.

Building a self-supporting, concrete ring that is 120 feet deep and 80 feet wide is no easy task, especially given the difficult ground conditions near South Jackson Street. STP crews have completed more than half of the underground piles and are working around-the-clock, seven days a week to complete the approximately 31 remaining piles.

There are several reasons the work is taking longer than anticipated. One factor is the addition of 11 piles to the pit’s design, bringing the total number of piles to approximately 84. Crews are also working with exceptionally large interlocking piles, which are necessary to make the pit self-supporting without tiebacks or other reinforcements. A self-supporting pit is what will allow the tunneling machine to mine through its walls, but the large piles take longer to install than standard piles.

While pile work continues, crews are making progress on other areas of the repair plan on schedule, including:

  • Shipping repair pieces: The new main bearing has arrived in Seattle and will be assembled closer to the time it’s needed, likely this fall.
  • Manufacturing repair pieces: Other repair pieces, such as the new outer seal ring, the thrust seal ring and bearing block are nearing completion. After these pieces are fabricated and inspected, Hitachi Zosen will ship them to Seattle.
  • Assembling a 300-ton crawler crane: This crane will be used to help assemble the 600-ton crawler crane. Pieces of that crane will arrive in September and assembly will begin shortly thereafter.
  • Assembling a 600-ton crawler crane: This crane will be used to assemble the modular lift tower (massive red crane) that will lift the largest pieces of the machine from the access pit. Parts of that crane will also arrive in September and assembly will begin in late September.
  • Assembling the 2,000-ton modular lift tower: Starting in late July and continuing through fall, crews will begin to stage the modular lift tower. Parts of the modular lift tower will arrive over the next several months beginning in late July.

We will continue to update you on STP’s efforts to resume tunneling by March 2015. You can watch the access pit take shape on our time-lapse camera, and view photos of recent construction on Flickr.
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Early warning – Four-day closure of SR 99 coming in late August

In late August, crews building the future north portal of the SR 99 tunnel will close SR 99/Aurora Avenue North near South Lake Union for four days. During this closure, crews will demolish and replace the section of SR 99 that crosses above Broad Street.

To minimize the need for additional closures, separate crews will complete the following work elsewhere along the SR 99 corridor during this time:

  • Utility work at Harrison Street.
  • Concrete panel replacement in SODO.
  • Expansion joint repairs on the Alaskan Way Viaduct near the Seneca Street off-ramp.
  • Ivy removal from the viaduct.

Closure information

Drivers should plan ahead for SR 99 closures from Friday night, Aug. 22 to Wednesday morning, Aug. 27. View a map of the closure.

  • From 10 p.m. Friday, Aug. 22 to 5 a.m. Monday, Aug. 25, SR 99 will be closed in both directions from the West Seattle Bridge to Valley Street.
    • Northbound SR 99 will be open from South Royal Brougham Way until midnight on Friday, Aug. 22 for exiting Seahawks traffic.
  • From 5 a.m. Monday, Aug. 25 to 5 a.m. Wednesday, Aug. 27, SR 99 will be closed in both directions from the south end of the Battery Street Tunnel to Valley Street.

Driver tips

Travelers who use SR 99 should consider the following:

  • Allow plenty of extra time and expect additional congestion on alternate routes including I-5 and surface streets.
  • Leave early or delay your trip to avoid traveling during peak commute periods in the morning and afternoon.
  • Delay or reschedule discretionary trips.
  • Consider telecommuting.
  • Choose an alternative travel mode such as King County Metro, share a ride in a car or vanpool, or walk or ride a bicycle. 

Know before you go and have a backup plan

Those who must drive are encouraged to stay engaged and check traffic conditions frequently via WSDOT’s web, mobile and phone-based traveler information systems.

  • The Seattle traffic page contains updated road information including links to traffic cameras.
  • The travel alerts website provides real-time information about blocking incidents.
  • WSDOT’s mobile app offers information for travelers on the go.
  • @wsdot_traffic provides Twitter updates about travel issues.
  • 5-1-1 offers traffic updates.
  • The What’s Happening Now page chronicles closures and issues affecting travelers.
  • Learn more about your commute and travel choices.

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Milepost 31 Speakers Series – Bertha and progress on the SR 99 Tunnel Project

Seattle Tunnel Partners, the contractor hired by WSDOT to design and build the SR 99 tunnel, is working to repair the SR 99 tunneling machine. Join us to learn more about STP’s plan to resume tunneling by the end of March 2015, and learn about the other work happening to replace the viaduct.

  • 6 – 6:30 p.m.
  • Thursday, Aug. 7
  • Milepost 31, 211 First Ave. S., Seattle
  • Admission is free

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Alaskan Way Viaduct Replacement Project Construction Update – January 2014

steelpipeProgress made in search for tunnel blockage

It was a busy holiday season for crews working to get Bertha, the SR 99 tunneling machine, digging again. While we still can’t say for sure what halted the machine on Dec. 6, we’re much closer to finding an answer than we were when all of this started.

Here’s a recap of what crews have been up to since the blockage occurred:

  • On Dec. 7, our contractor, Seattle Tunnel Partners (STP), began prepping the machine and surrounding environment so crews could inspect the cutterhead and excavation chamber safely.
  • On Dec. 17, a brief visual inspection of a small section of the excavation chamber and cutterhead found dirt, sand and cobbles – nothing unusual.
  • Over the holidays, STP crews were on-site to drill dewatering wells, maintain the machine and switch out cutting tools on the machine’s face.
  • Earlier this week, STP drilled 17 small-diameter, exploratory holes near the front of the machine to see if they could identify an obstruction. They encountered obstructions in four of the holes.
  • On Jan. 2, the water pressure was low enough and enough soil was removed from the excavation chamber to inspect the top 15 feet of the chamber.
  • This inspection showed an 8-inch-diameter steel pipe protruding through one of the many openings in the cutterhead. We believe the steel pipe is a well casing installed by WSDOT in 2002 after the 2001 Nisqually earthquake to better understand how groundwater flows through this area. The location of this pipe was included in reference materials in the contract.
  • We also believe at least some of the obstructions found by the exploratory holes are pieces of the 2002 steel pipe, which could be a contributing factor in the delay of boring.
  • Other potential factors include changing soil conditions that may have caused excessive wear of cutting tools, potential objects in front of the cutterhead or objects in the lower portion of the excavation chamber that still aren’t visible.

Next steps

STP is considering several options to remove the steel pipe and identify other potential obstructions.

While Bertha is stopped, other work is taking place. This includes:

  • Extensive construction on the north and south ends of the tunnel.
  • Preparatory work to dismantle the push frame and temporary tunnel rings in the launch pit.
  • Preparatory work to reconfigure the launch pitand build the roadway within the tunnel.

​It’s too early to speculate about the cost or long-term schedule implications of this issue. We’ll continue to work with STP to determine ways to make up time lost during the blockage. Our focus is now on addressing this issue safely and in a timely manner so we can resume tunneling as soon as possible.