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* STRUCTURAL
OBSERVATIONS:
BRIDGES

Contact: Marc Eberhard, eberhard@u.washington.edu

Earthquake Damage Facts and Figures: Bridges


Seattle:
City Bridges:

Magnolia Bridge
  • closed
  • transverse concrete 12 T-braces broken
  • estimated repair time 6 months at $1 million
Emerson St. viaduct
  • sacrificial expansion joint sacrificed
Swing Bridge
  • bumper block sheared off indicating bridge may have over-traveled.

County Bridges:

South Park Bridge Bascule Bridge

State Bridges:

Bascule Bridge
1st Avenue S.
  • misaligned 3 inches
4th Avenue s. onramp to I-90
  • closed
I-5 Holgate overpass, Seattle
  • short column
Hwy 99 overpass, Spokane
  • restrainer
Spokane viaduct Tolt Bridge, Snoqualmie
NE Tolt Hill Rd where it bridges the Snoqualmie River (Thomas guide pg 569-gridC2)
  • older concrete double tee construction, sitting on timber columns and bents
  • multiple short spans - sounds like the damage is in the concrete double tees near the bearings - Bridge still closed

Olympia:

4th Avenue Bridge
  • bridge is an older structure that suffered damage in the 1949 magnitude 7.1 event
  • the bridge was in line for demolishing
  • railings fell from top onto the road
  • columns at the south end of the bridge showed confinement damage at the top
  • vertical and shear cracks occurred in one column which carried an expansion joint

Tacoma

South Park Bridge
Bascule bridge over the Duwamish River just south of the 1st ave bridge
14th Ave S/16th Ave S
  • some elements damaged, unable to open to water traffic
  • bridge reopened to vehicular traffic

Bellevue

Lakemont Boulevard Bridge
  • found cracks
Meydenbauer Bridge
  • cracks in main support girders on the east side

Bremerton

Warren Avenue Bridge
  • closed by the city



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