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
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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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Case study #3
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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Case study #3
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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