Transcript Case Study
Approaches to Historic Bridge Rehabilitation
Case Study #3
Yaquina River (Eddyville) Bridge
(Pony Truss)
by
Ray Bottenberg,
Oregon Department of Transportation
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Case study #3
Yaquina River (Eddyville) Bridge
Location
Milepoint 23.38 on US 20 in Eddyville, Oregon
Description of Setting
Town of <1000 in rural, forested area
Description of Bridge
Date
Original construction 1923
Widened 1962
Length
132 Feet
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Span Type (s)
80 foot steel pony truss
Precast reinforced concrete channels in approaches
Case study #3
Yaquina River (Eddyville) Bridge
Date and Cost of
Rehab
2006
$424,000
Designer
ODOT – Ray
Bottenberg
Client/Owner
ODOT
Contractor
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S&K Painting
Case study #3
Load Rating Issue
Bridge and old alignment of US 20 to be given to
Lincoln County.
County wanted load rating before accepting bridge and
roadway.
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How Load Rating Issue Was Resolved
Field visit with rebar locator to recreate As-Built data
Field visit with Portable Hardness Tester to verify material
strength
~14% increase in strength over design values
Strain gage survey
Left: Strain Gage Monitoring
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Right: Typical Strain Gage Installation
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How Load Rating Issue Was Resolved
Removal of 4-6” Asphalt concrete wearing surface and replacement with 2” wearing
surface
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This eliminated enough dead load to solve the load rating issue
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Corrosion Issues
Bridge and old alignment of US 20 to be given to Lincoln County.
County wanted corrosion damage addressed.
Sufficiency rating of 26.8 partially a result of corrosion damage and paint
condition.
Coating was approximately 40 years old.
Left: Lower chord tie plate corrosion
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Right: Corrosion of floor beam
connection above bearing
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Left: Lower chord tie plate corrosion damage
Right: Section loss in lower chord connection plate
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How Corrosion Issue Was Resolved
40-year-old Lead-Based Coating System replaced with 3-coat
cured urethane system after abrasive blasting.
corroded tie plates and lacing bars were replaced in-kind.
Lower chord connections and end floor beam connections
received extra intermediate coat of urethane-tar.
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Case study #3
How was Section 106 handled
Bridge was determined “Potentially Eligible” under Section 106.
Project cleaned and recoated the bridge and repaired minor
corrosion issues.
Repair details were designed as “In-Kind” replacement of corroded
components.
Repair details were reviewed and concurred by State Historic
Preservation Office.
Original bridge color (black) determined from 1923 files, project
specified black color.
“No Adverse Effect.”
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Case study #3
How was Section 4(f) handled
Section 4(f) was largely a non-issue for this project.
The historic bridge was not demolished.
“No Adverse Effect” on historic quality.
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Case study #3
Lessons Learned/Conclusions
Hardness testing and strain gage testing are reasonable steps
to refine load rating, when bridge shows no signs of overload
distress.
Remove excess ACWS.
Minor rehabilitation work and change in use can significantly
improve sufficiency rating.
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