South Park Bridge - Construction project updates

Construction update #11

April 3, 2012

Construction update #10

Feb. 27, 2012

Fish window ended February 15 – critical construction milestone met

The allowable work period for in-water construction concluded on February 15. Kiewit-Massman, the contractor for the project met this critical deadline for completing all work that touched the water or the riverbed, such as dredging outside the caissons and driving or extraction of piling and cofferdams. Here is a summary of the caisson construction during the six-and-a-half-month fish window that began August 1 last year:

• Spread a sand blanket over the riverbed in the construction areas to limit disturbance of the contaminated river silt;
• Built cofferdams to control turbidity and isolate main bridge pier construction from the river;
• Treated water inside the cofferdams with a system made up of 26 Baker tanks;
• Set the 188,000 lb. steel cutting shoes;
• Excavated 6,000 tons of contaminated sediment;
• Poured multiple lifts of concrete for the north and south caissons;
• Sank the caissons about 50’ into the riverbed;
• Removed the sheet-pile cofferdams.

Work on the main piers above the water comes next. This will include installing formwork and rebar for the leveling slab (visible 60’ x 90’ cantilevered platform atop the hidden 60’ x 60’ caisson), pouring the pier walls, and sinking the caisson to final tip elevation.

Construction of the approach piers is now underway, starting with the installation of drilled-shaft substructure and continuing with the construction of concrete columns and abutment walls.

Road improvements on 14th, Sullivan, Dallas starting March 19

Construction for the new South Park Bridge is moving right along. During the next phase of work you'll see a number of road improvements being made. We will be realigning 14th Avenue South to connect it with the new bridge and putting in a four-way intersection at 14th and Dallas Avenues to improve traffic safety.

To keep the project on schedule, portions of 14th Avenue South, South Sullivan Street and Dallas Avenue South will be closed starting Monday, March 19, so that construction crews can tear up the existing roadway, install utilities and storm drains, and put in new road improvements.

14th Avenue South from the South Park Bridge to South Cloverdale Street will be reduced to two lanes (one lane in each direction). On-street parking will be restricted on 14th Avenue South from March 19 to May 17. Driveway and pedestrian access to businesses will be maintained during construction. Informational signs in English and Spanish will be posted in advance and will remind the community that businesses are open. Short sections of South Sullivan Street and Dallas Avenue South directly off 14th Avenue South will be closed. Local access to all residents and businesses will be provided during construction. See the informational flyer. (138KB .pdf)

This phase of construction is scheduled to last no more than 60 days, ending by May 17. Construction hours will be from 7 a.m. to 3:30.p.m., Monday through Friday.

Around-the-nation work on the bridge

Offsite fabrication of various bridge components is underway around the country. In Montana, a steel fabricator is busy manufacturing the four bascule girders, each half the length of a football field. In Utah, another steel fabricator has started production of the trunnion frame, the huge steel structure that will support the moveable spans inside the main piers. In Alabama, a machine fabricator is putting together the machinery components, the trunnion shafts and rack and pinion components. The steel deck grating is being fabricated in Pittsburgh. In Tacoma, pedestrian rail fabrication will begin soon. Finally, here in the SODO area, steel components are being cast for caisson construction.

Following are photos taken at Stinger Welding Inc., in Libby, Montana the week of Feb. 13, 2012. Stinger is fabricating the moveable bridge leaves for the new bridge.

One of many floorbeams that will span between the bascule girders. Enlarged view (394KB .jpg)

Looking down the length of a bascule girder with the curved lower surface and multiple stiffeners. Enlarged view (384KB .jpg)

Looking down to the tip of the bascule girder. Girder will rotate about hole partially seen in foreground. Enlarged view (332KB .jpg)

For more information please contact the South Park Bridge Construction Information Line: 206-263-9979 (Monday through Friday, 8 a.m. to 5 p.m.)

Construction update #9

Feb. 16, 2012

Temporary dog park will close on Feb. 29, 2012

Thank you South Park pups and owners for your continued support of King County's South Park Bridge Replacement Project!

In September 2010, the South Park community came together with King County's bridge construction project team and City of Seattle to create the temporary South Park Bark Dog Park at 8457 Dallas Avenue South. Slated for future construction use, the site was a convenient location for a temporary dog park until the bridge contractor required the area for the construction project.

While it has been fun to frolic and fetch, the site is now needed to make way for construction equipment and materials staging starting the first week in March. The temporary dog park will close on Feb. 29, 2012.

The site's close proximity to the South Park Bridge construction site will allow the team to access materials quickly and efficiently, and will help keep the bridge project on schedule. We have been very fortunate to have the contractor extend the temporary use of the site for as long as they have.

Night work ended on Feb. 3, 2012. All crews resumed regular daytime work hours, 7 a.m. to 3:30 p.m., Monday through Friday.

For more information about the South Park Bridge Replacement Project, please contact King County Department of Transportation, Community Relations, at 206-684-1154.

Construction update #8

Dec. 16, 2011

Things are getting progressively busier down at the construction site, though it’s hard to see since most of the work is being drilled underground or sunk into the riverbed.

During the past few weeks, the crew started work on the approach piers while continuing to build the caissons (the foundation structures that will support the main piers in the water).

The drilled shafts for the piers up on land on the South Park side are almost complete, and work on the piers on the Boeing side of the river will begin shortly. Construction of caissons for both of the main piers is also progressing. It’s a repetitive sequence of tying rebar, adding forms, pouring concrete, stripping the forms, and excavating to sink the caisson, alternating between the two main piers. This work will continue to keep day, night, and Saturday crews busy over the next couple of months. The north pier has already been sunk 33 feet toward its final depth of 100 feet below the riverbed; the south pier has been sunk 14 of a total of 70 feet. Off site, fabrication has begun on the moveable spans, bascule girders, and trunnion frame (the huge steel structure that will support the moveable spans).

To see photos of this work, visit the project photodocumentary webpage. If you have questions, please don't hesitate to give me a ring at 206-684-1154 or send me an email.

Ashley DeForest, Communications Planner
King County Department of Transportation

Construction update #7: Night work starting

Oct. 10, 2011

Starting Monday, October 10, South Park Bridge construction hours will be extended into the evening to ensure the project stays on schedule. Construction is generally expected from 7:00 a.m. to 3:00 a.m., Monday through Saturday. It is not expected that this entire window of work will be utilized all weeks or all days.

Regular construction noise is expected from activities such as large crane and concrete equipment operations. To minimize noise impacts, when possible the contractor will turn off engines, use noise blankets and muffle back-up alarms. To ensure a safe work zone, please note that back-up alarms cannot be turned off.

The number of crew staff will vary from approximately 6 to 20 individuals, and artificial light sources will provide illumination to the work area in the water. All light will be directed away from surrounding areas with shields or strategic placement.

For more information:

• Ashley DeForest, Community Relations Planner: 206-684-1154 or ashley.deforest@kingcounty.gov
• South Park Bridge Construction Information Line: 206-263-9979 (Monday through Friday, 8 a.m. to 5 p.m.)

Thank you for your patience and support during South Park Bridge construction!

Noise variance update

Sept. 7, 2011

Starting in August, construction hours will be extended into the evening to ensure the project stays on schedule. To minimize noise impacts to the community the contractor will, when possible, turn off engines, use noise blankets, and muffle back-up alarms. We appreciate your patience as we make progress on the bridge. Read more about potential noise impacts. (260KB .pdf)

Construction update #6

Sept. 7, 2011

Thanks to everyone that came to visit us at the Duwamish River Festival—what a fun event!

I know it’s hard to see a lot of the construction activity down on the river, so here’s a quick update. You can also see some amazing photos of the construction progress taken by John Stamets on our website at www.kingcounty.gov/southparkbridge. If you have questions, please don't hesitate to give me a ring at 206-684-1154 or send me an email at ashley.deforest@kingcounty.gov.

Construction is moving right along

The 70-foot square cofferdam template for the north bridge pier was completed last week. This temporary structure is designed to give workers a dry work environment as they excavate the area for the new bridge pier. Now that the cofferdam is in place, the contractor’s team can start pumping out water, which will be treated in one of 26 big steel containers located on the Boeing side of the project.

Once the water is gone, the contaminated river silt inside the cofferdam will be dredged out, loaded onto a barge, transferred to a site near the First Avenue South Bridge, and finally transported to eastern Washington for safe, upland disposal. Once the contaminated soil is properly disposed, the cofferdam will be filled back up with sand and the massive 225-ton steel cutting shoe being fabricated in Tacoma will be placed atop the “sand island.” This will signal the start of a repetitive excavate, pour concrete, and excavate some more process that will take place the remainder of this year and into the next.

Keep your eyes out for the same construction sequence happening on the south bridge pier in the coming weeks.

On the horizon

The huge DB General barge is coming back to town twice in September to perform some heavy lifting. Crane pads were erected within each bascule pier of the old bridge to support a large crane that will help construct the new bridge piers. The DB General lifted the north crane into place a few weeks ago and the southern crane will be lifted into place this month. Two full waterway closures have been approved by the Coast Guard for this work:

• Sept. 7, 2011 (7 a.m.) through Sept. 9, 2011 (7 p.m.)
• Sept. 21, 2011 (7 a.m.) through Sept. 23, 2011 (7 p.m.)

Sept. 12, 2011 - Dredging contaminated soil from Pier 4 cofferdam. Photo by John Stamets Enlarged view (156KB .jpg)

Sept. 7, 2011 - South cofferdam template arrives on site. Photo by John Stamets Enlarged view (142KB .jpg)

Sept. 6, 2011 - Cofferdam pumped out partially to test for leaks. Photo by John Stamets Enlarged view (137KB .jpg)

Aug. 30, 2011 - Cofferdam construction at low tide - and lunchtime. Photo by John Stamets Enlarged view (147KB .jpg)

Ashley DeForest, Communications Planner
King County Department of Transportation

Construction update #5

Aug. 16, 2011

In case you were wondering, here's an update of what's happening down at the bridge construction site. If you have questions, please don't hesitate to give me a ring at 206-684-1154 or send me an email at ashley.deforest@kingcounty.gov. You can also find me this Saturday at South Park's debut Luche Libre event, which I am really looking forward to.

Work underway

Gears in the north motor room have been removed and stored on-site, and those on the South Park side are being salvaged. The massive steel cutting shoes for the caisson foundations are being fabricated in Tacoma. These are the 225-ton steel assemblies at the bottom of the caissons that will cut through the soil as caisson excavation progresses. Concrete formwork for the bascule caissons is being built on-site.

Removal of a portion of the red brick road began July 27, and bricks are being stockpiled on-site. Many of these bricks will be salvaged for reuse in the new bridge project.

Protecting the Duwamish

A sand blanket has been placed over contaminated river silt in the construction area to limit disturbance of the silt. Dozens of large steel tanks are being installed on the north side of the project in the Boeing parking lot. These containers will treat water pumped from the Duwamish River. They'll eventually be installed on both banks of the river and will be connected to a filtering system that will treat the water before it is discharged into the river.

On the horizon

The cofferdam templates will be floated into place soon, and sheet piles will be driven to form the 70-foot square cofferdams in which the two main bridge piers will be built. At the same time, steel crane pads are being erected inside and over each bascule pier of the old bridge. Each of these pads will support a large crane that will help with new bascule pier construction.

The DB General, the huge barge-mounted crane that was used to remove the bascule leaves from the old bridge a year ago, will return this week to lift large cranes from a barge up to the top of the bascule piers.

Aug. 17, 2011 - Huge barge crane (the DB General) is parked for two days in channel between piers. Photo by John Stamets Enlarged view (140KB .jpg)

Aug. 17, 2011 - Cofferdam template is almost ready for installation near north bank. Photo by John Stamets Enlarged view (112KB .jpg)

Ashley DeForest, Communications Planner
King County Department of Transportation

Construction update #4

July 28, 2011

As you've probably noticed, construction work is really getting underway. In addition to their work on the infiltration pond and water treatment system, the contractor is prepping the tops of the old bridge piers to be used as crane pads. On the north (Boeing) side of the project, the steel crane pad is almost assembled and the gears from the north motor room have been salvaged for reuse as part of the new bridge. Similar work on the South Park side of the project will begin soon. The contractor also started removing the red brick road this week—and don’t worry, those bricks will also be salvaged for reuse.

The six-and-a-half-month window for in-water construction work begins on Monday, Aug. 1. Small temporary "floats" have been assembled and are being tied together to form a large square barge at the north main pier that will support a 70-foot square steel template. When the fish window opens and in-water work is allowed, sheet piles will be driven through each template to create a dry work space (cofferdam) around the main pier. Similar work for the south main pier will follow. We’ll continue to work closely with the Muckleshoot Tribe to coordinate this construction work during the fishing season.

For more information about the construction schedule and activities, see our website. And if you have any questions, please feel free to contact me.

Enjoy a safe and fun Night Out celebration next Tuesday!

Ashley DeForest, Communications Planner
King County Department of Transportation

Construction update #3

July 1, 2011

Thanks to everyone who joined us for tours of the archaeological dig! I learned a lot about prehistoric, seasonal fishing camps and how the mysteries of 1,000-year-old salmon bones are deciphered. To watch the highlights, check out our video of the tour.

You’ve also probably noticed the construction fencing going up around the staging area at the south end of the bridge. Starting the week of July 18, the contractor’s team will be working in the staging area, fabricating the form work for the caissons (watertight structures that will be used to build the foundations of the bridge piers).

They’ll also be bringing in equipment to the tops of the old bridge piers to prep the area for crane pads. In August, the contractor will start in-water work to build the piers for the new bridge.

For more information about the construction schedule and activities, check back here frequently. And if you have any questions, please feel free to contact me.

Enjoy a safe and festive holiday weekend!

Ashley DeForest, Communications Planner
King County Department of Transportation

Construction update #2

June 9, 2011

It's been a few weeks since our last update, and here's what's been happening!

The construction management team--made up of King County Road Services staff members and our bridge design and construction consultants--has officially moved into its new construction offices on Dallas Street. When I visited them there last Friday, they were all raving about the neighborhood lunch spots.

The archaeological dig is now underway. A team of consultants is digging as many as 22 excavation pits west of the old bridge approach in search of materials such as shells, animal bones, stone tools, and hearths. So far, they’ve opened six excavation pits and have found shell and other artifacts in five of these. Some of the thickest intact cultural layers are being found under the road at the south end of the old bridge. All of the items found will be analyzed before being sent to the Burke Museum.

Personnel from Kiewit-Massman, the county's contractor for the South Park Bridge replacement project, are moving into their offices on the Boeing side of the bridge. They’re also busy ordering the materials needed for the project, including machinery that will run the bridge drive system that opens and closes the bridge. While many of the materials will be purchased from regional vendors, these special motors and gears for the drive system will be coming from Alabama.

Over the next couple of months, you'll see the contractor's workers bringing materials and equipment into the construction staging area on the south side of the bridge. Starting in August, the contractor will be salvaging gears from the pier of the old bridge for reuse in the pedestrian railings of the new bridge. They'll also be starting in-water work to build the piers for the new bridge.

For more information about the construction schedule and activities, see the project website. We'll also be sharing updated information at a variety of neighborhood meetings in the coming weeks, including the June 14 South Park Neighborhood Association meeting, the June 20 Georgetown Community Council meeting, and the June 21 South Park Neighborhood Association Traffic Subcommittee meeting. Maybe I'll see you at one of those--be sure to say "hi" if I do!

Ashley DeForest, Communications Planner
King County Department of Transportation

Construction update #1

May 18, 2011

Thanks to everyone who took part in the groundbreaking ceremony on May 5. It was a huge success and we look forward to getting construction underway in the coming weeks.

You can stay informed about construction and reach us in a number of ways:

• Sign-up for e-mail alerts
• Visit this website or our project website
• Call our staffed Construction Information Line at 206-263-9979
• Send an e-mail to southparkbridge@kingcounty.gov
• Contact Ashley DeForest at 206-684-1154 or ashley.deforest@kingcounty.gov

Here are just a few things you'll see in the coming weeks...

Who is moving into that new trailer on Dallas Street?
The construction management team—made up of King County Road Services staff members and our bridge design and construction consultants—will be moving into their new construction offices on Dallas Street within the next week. Their job will be overseeing the construction to make sure it is on schedule, within budget, and built in accordance with the design plans, specifications, and permit conditions. You'll probably see a few familiar faces from King County, including Tim Lane, deputy project engineer, and Trinh Truong, project manager. Be sure to say hi!

What was here 1,000 years ago?
A past survey of the construction area found three prehistoric archaeological sites. One of these is in the path of the new bridge and under the footprint of the old bridge. Around 1,000 years ago, the main channel of the Duwamish River flowed about 350 feet south of the existing channel, and the ancestors of the Duwamish people lived on the banks of the river. (This channel had become an oxbow, or a U-shaped bend in the river, and was filled in during the early 20th century.) A team of consultants plans to dig as many as 22 excavation pits west of the old bridge approach in search of archaeological materials such as shells, animal bones, stone tools, and hearths. Any items found will be analyzed before going to the Burke Museum.

When will we see the contractor?
Kiewit-Massman, the joint-venture contractor selected for the project, received its official "Notice to Proceed" on May 17, which means that work on the bridge construction can begin. The first order of business will be to move in to their on-site offices, which are on the Boeing side of the bridge. Next you'll see their workers bringing materials and equipment into the construction staging area on the south side of the bridge. Starting in July, the contractor will start salvaging the gears from the pier of the old bridge for reuse in the pedestrian railings of the new bridge. (Visit the project website to see a rendering of the new railing.)

Where can I learn more about the construction schedule and activities?
Information about the construction schedule and activities is available on the project website. We will be sharing updated information at a variety of neighborhood meetings in the coming weeks – stay tuned!

Information on the South Park Bridge website is available to people with disabilities in alternate formats upon request by calling 206-263-6482 or 711 for the TTY relay service.

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