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Bridge Rehabilitation, Replacement and Seismic Retrofit
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Ballard Bridge Seismic Retrofit

Work Progress Update:

March 15, 2013

On Top: There still have been no closures of any vehicular travel lanes or sidewalks on top of the bridge for the seismic retrofit.

On Land: Work under the bridge continues on the north side of the Ship Canal, although no longer adjacent to Shilshole Avenue NW.  Work is also now underway on the south side, flanking the South Lake Union Trail.  Before long the contractor will erect work platforms over the Trail, enabling it to remain open while work proceeds overhead, rather than having to close the Trail for 30 days as we had previously announced.  Trail users may experience some very brief interruptions by flaggers while this platform is being placed (or dismantled) and possibly at other times, but these interruptions will be few and short. 

In the Water: Steel and concrete column jackets have now been installed around 8 of the 11 piers which are scheduled for this in-water work.  No work will be done in the water during the window of time set aside for migratory fish to pass through the Ship Canal – April 15 through October 1.

Over the Water: The barge previously used to stage in water work will shortly be exclusively used to support other work under the bridge, namely installing new steel diaphragms, longitudinal blocking and deck joints plus new concrete seat extensions and restrainers.

February 1, 2013

On Top: To date there have been no closures of any vehicular travel lanes or sidewalks on top of the bridge for the seismic retrofit.

On Land: Work is continues under the bridge on the north side, performed from scaffolding erected north of Shilshole Avenue NW.  On Monday February 4th additional scaffolding will be placed around the bridge pier in the middle of the road, between Shilshole’s east and west-bound lanes, narrowing the 2 travel lanes directly under the bridge to 11 feet wide.  This scaffolding and the temporary narrowing will be in place for the several weeks as workers add concrete restrainers to the bridge structure to increase its seismic stability. 

The scaffolding supports formwork for additions to the concrete bridge structure just under the bridge deck.

In the Water: Steel and concrete column jackets have been installed around 5 of the 11 piers which are scheduled for this in-water work.  Each pier is composed of two columns and a crossbeam on which the bridge deck rests.  Progress can be seen in the pair of photos below; the tubular structures, which extend below the water surface, are the concrete filled steel column jackets.

Next is a photo of workers inside the coffer box that is placed while: the existing column is prepared, the steel jacket is welded in place and the concrete is poured and cures.  Three different coffer boxes are in use, moving from pier to pier as the work proceeds.

Click here to view past updates

To receive information about the project during construction via our e-mail list, CLICK HERE.


The Ballard Bridge (flanked by its approach structures) as seen from the east.

The Ballard Bridge carries 4 lanes of vehicular traffic, plus two sidewalks, over the Lake Washington Ship Canal between Interbay to the south and Ballard to the north. It is composed of three portions: a 295 foot long central portion and the north and south bridge approaches of 758 and 1801 feet respectively. The central portion (called a bascule) opens to allow ships taller than 44’ to pass between Puget Sound and Lake Washington on the Ship Canal.

Retrofit Project Overview

The Ballard Bridge Seismic Retrofit Project is part of Seattle’s city-wide program to upgrade its bridges.  This project will prevent the Ballard Bridge approaches from catastrophic failure in a higher design level earthquake (with an expected 1,000-year return period) and will  allow the bridge to remain fully operational following a lower design level earthquake (with a 100-year return period). 

Most of the work will be done beneath the bridge and will not be visible from on top.
The seismic retrofit will include the following types of work in strategic locations:

  • column jacketing
  • reinforced concrete seat extensions, restrainers, plinth retrofits, pier diaphragm bolsters and girder strengthening
  • replacement of longitudinal restrainers
  • addition of steel longitudinal blocking and steel deck joint restrainers
  • replacement of knee bracing with steel pier diaphragms.

Construction began in July of 2012 and may take up to 22 months to complete. In general, work may be classified as “on land”, “over water” and “in water”. The contractor hopes to complete all the “in-water” work (pier reinforcement and subsurface column jacketing”) by May 2013. On land work (new steel diaphragms, concrete restrainers, longitudinal blocking, deck joint retrofits and seat extensions) will take place under both the north and south approaches simultaneously through most of the project. The over the water work activities are much the same as those on land, but will be done primarily after the in water work is finished, from scaffolding erected on the contractor’s custom built barge.

Bridge History


Note the wooden timbers in the approach structure to the left.

In 1917 construction of the Ballard Bridge (designed by A.H. Dimock) was completed, with wooden bridge approach structures.

In 1939 the wooden bridge approaches were completely replaced with concrete and steel. A fascinating film made during that re-construction may be seen here.

In 1958 the north ramp was widened to provide access to and from Leary Way NW

In 1982, the bridge was placed on the U.S. National Register of Historic Places.

In 1989 the Loma Prieta earthquake struck San Francisco and in 1994 the Northridge earthquake struck Los Angeles.

In 1994 SDOT added seismic restrainers and replaced the steel deck grating on the bridge as part of a city-wide program.

In 2002 SDOT carried out an electro-mechanical rehabilitation to update the operating portion of the bridge.

In 2006 SDOT evaluated Seattle’s bridges, assessing their vulnerability to seismic events and the importance of these routes to Seattle area traffic. That evaluation resulted in a decision to seismically retrofit the approaches to the Ballard Bridge, as well as several other structures.

In 2009 the engineering firm of Berger ABAM began design work on the Ballard Bridge seismic retrofit and in 2012 the permitting for the project was concluded.

Project Construction Impacts

A key design criterion for Ballard Bridge seismic retrofit project was to minimize impacts on traffic across the bridge; as a result most of the work will be done from down below.

If they are needed, vehicular lane closures will be limited as follows:

  • no southbound lane may be closed between 4:30AM and 10:00AM
  • no northbound lane may be closed between 3:00PM and 10:00PM
  • no two lanes be closed at the same time (except during full closures, covered below).

In addition, one sidewalk or the other could be closed between 7:00PM and 6:00AM (but never both sides at the same time).

The project retrofit work is also allowed 3 full weekend long closures of the bridge to all vehicular traffic. (This is same number of full closures used during the replacement of the approaches on the Fremont Bridge in 2007).  If needed these closures (on non-consecutive weekends) will be between 10PM on Friday and 6AM on Monday morning and will be announced at least 2 weeks in advance.  At this point in time no full closures of the bridge are anticipated.

Finally, the Ship Canal Trail (which passes underneath the southern approach to the bridge) will be closed for up to 30 consecutive days at some point.

Advance notice of vehicular lane or sidewalk closures will be provided through email notices, website updates, electronic display boards, and traffic alerts. Joining the e-mail list by CLICKING HERE is the best way to stay informed of upcoming closures and detour routes.

The project will create both noise and vibration, particularly so during the removal of certain structural elements. Normal work hours on this project are 6AM to 4PM Monday through Thursday, though work will also take place on Fridays, at night or on weekends at times.

If work occurs after 10PM, the contractor will utilize construction methods to reduce noise impacts (such as using rubber bed liners in trucks and the less intrusive backup warning devices).

Traffic Signage and WebCams

Four electronic signboards will be used to keep commuters informed of upcoming lane closures periods on the bridge. The messages on these boards will typically include the dates and times of closures using the abbreviations NB and SB for northbound and southbound respectively.

The SDOT Traveller’s Information Map provides up-to-date traffic information, with traffic alerts, links to live traffic video feeds and other information that may help in avoiding delays. Cameras are located on 15th Ave at NW 85th, NW 65th, Market Street, Leary Way NW, W Emerson, and W Dravus, as well as on Elliott and the Fremont and Aurora Bridges. (The location of the camera is given at the top of the video feed, and the direction the camera is facing is shown on the second line.)

Video feeds from the cameras closest to the Ballard Bridge are located below. (Reload the page to refresh the images.)

Reload the page to refresh the images.

Environmental Considerations

SDOT has conducted environmental reviews of the Ballard Bridge Seismic Retrofit Project to consider impacts associated with social/economic issues, biological resources, bicycles/pedestrians, historic/cultural resources, visual quality, land use, wetlands, and noise and vibration.

If you have any questions regarding the environmental permitting or associated protection measures on this project please contact: Mark Mazzola, SDOT Environmental Coordinator, at 206-733-9117 or mark.mazzola@seattle.gov.

Nearby Projects

SDOT’s staff is working to minimize impacts of the Ballard Bridge Seismic Retrofit project by coordinating activities with other projects in the area:

Project Budget & Funding

The total estimated project cost is $15.5M, which includes engineering, geotechnical work, structural design, permitting, and right of way management in addition to the construction.

The project is funded by Bridging the Gap, a nine-year levy for transportation maintenance and improvements. The $365 million levy was passed by Seattle voters in November 2006. The goal of the program is to create a strong foundation for Seattle’s transportation future by reducing the infrastructure backlog and investing in major transportation projects.

Recent History

10/1/2012 – The contractor began in-water work.

9/11/2012 – The contractor began erecting scaffolding at the north abutment.

7/30/2012 – The contractor began mobilizing on site.

6/1/2012 – The contract with Quigg Brothers was executed.

5/8/2012 – The low bidder, Quigg Brothers Inc. of Aberdeen, WA, was recommended to receive the contract.

4/18/2012 – The Ballard Bridge Seismic Retrofit bids were opened, with the lowest of 9 bids accepted totaling $7,092,370 – almost 5% under the Engineer’s estimate.

More Information?

More information about the retrofit project will be added to the website as the project moves forward.

We will keep people informed about the project during construction through regular e-mail updates. To join our e-mail list, please CLICK HERE.

If you have questions about the project, please contact: Art Brochet, SDOT Project Communications, 206.615.0786, art.brochet@seattle.gov


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