Seismic updates coming to I-5
Published 10:36 pm Monday, November 10, 2008
MOUNTLAKE TERRACE — The need to shore up several bridges on I-5 in south Snohomish County won’t likely be noticed by the people who drive over them — except, maybe, in an earthquake.
Work started Monday on a two-year project to reinforce 13 overpasses and underpasses in Lynnwood and Mountlake Terrace, and more than 900 statewide.
The bridges are safe under normal conditions but were found in a recent survey to fall short of current seismic standards, according to the state Department of Transportation.
The 2005 gas tax increase included $12.3 million for the work, said Aurora Jones, a spokeswoman for the transportation department.
Occasional lane closures might be required on I-5 for bridges that cross the freeway, and on side streets that pass below, depending on the location.
“It just depends on what each bridge needs,” Jones said.
The work started Monday on the underpass where Highway 104 passes beneath I-5, Jones said. No closures are expected at that location.
The bridges in Snohomish County range from Highway 104 on the south end to 164th Street SW on the north, a distance of six miles. At some locations, where southbound and northbound lanes are built separately, each structure is considered a bridge in itself.
Crews will strengthen the bridges in three different ways. One is to add concrete blocks between bridge girders to prevent lateral movement. Another involves widening concrete blocks on top of bridge columns to make them more stable. A third consists of reinforcing the columns by wrapping them in steel jackets.
The work is expected to be finished in late 2010.
Reporter Bill Sheets: 425-339-3439 or sheets@heraldnet.com.
Work sites
Following are the underpasses and overpasses in south Snohomish County scheduled for seismic reinforcement. For more information, visit www.wsdot.wa.gov/Projects/I5/KingSnoBridgeRetrofit.
I-5 at Highway 104 (3 bridges)
I-5 at 220th Street SW
I-5 at 212th Street SW (2 bridges)
I-5 at 52nd Avenue W. (2 bridges)
I-5 at 44th Avenue W. (2 bridges)
I-5 at 196th Street SW
I-5 at I-405
I-5 at 164th Street SW
