Load Rating Bridges with No As-Built Plans or Non-Engineered Bridges

Details

• Creators:
  Jáuregui, David V. ; Newtson, Craig M. ; Weldon, Brad D. ; Aguilar, Carlos V ; Cortez, Tamara M ; Shikurye, Dagmawie D ; Ouyang, Yongguan
• Corporate Creators:
  New Mexico State University. Department of Civil Engineering
• Corporate Contributors:
  New Mexico. Department of Transportation. Research Bureau ; United States. Department of Transportation. Federal Highway Administration
• Subject/TRT Terms:
  Concrete Bridges Load Limits Nondestructive Tests Prestressed Concrete Bridges
• Publication/ Report Number:
  NM13STR-01
• Resource Type:
  Tech Report
• Geographical Coverage:
  United States ; New Mexico
• Edition:
  Final Report (5/17/13 – 7/31/15)
• Corporate Publisher:
  New Mexico. Department of Transportation
• Abstract:
  Off-system concrete bridges with no design plans are currently a concern in New Mexico as many exist throughout the State. Load rating of these bridges is problematic since the design documentation is limited or missing, thus creating uncertainties regarding the safe load limits for legal vehicles. Only a few states in the United States have formal procedures for load rating concrete bridges without plans. This project was conducted for the New Mexico Department of Transportation to develop a load rating procedure for planless concrete bridges, in particular prestressed structures. In accordance with the AASHTO Manual for Bridge Evaluation, a reinforced concrete slab bridge and five prestressed concrete bridges (including two double T-beam, two box girder, and one I-girder) were evaluated using advanced analyses and experimental methods (including load testing and/or non-destructive material evaluation techniques). A multi-step procedure was implemented that included estimating the material properties from past specifications and amount of prestressing steel via Magnel diagrams; verifying the steel estimate with a rebar scanner; testing the bridge at both diagnostic and proof loads based on strain and acoustic emission measurements; and rating the bridges using the proof test results. Rating factors were determined for AASHTO and New Mexico legal loads based on the serviceability limit state (i.e., concrete cracking). Using the AASHTOWare Bridge Rating (BrR) program, rating factors were also computed for the strength limit state (i.e., shear or flexural capacity) based on the measured bridge dimensions and estimated material properties. For the reinforced concrete slab bridge, only the BrR evaluation was needed. The serviceability ratings from proof testing and strength ratings from the BrR program were ultimately compared to determine the final load ratings and need for posting the bridges.
• Format:
  PDF
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha-512:a1484fe1103c29d47c4a5d2aa263c58f929c50368c6e8b30d692ab342eccb805c135711739ae217e29f16099da649105cf8d4962dfe6723b339f090d299efda2
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/87291/dot_87291_DS1.pdf
• File Type:
  [PDF - 13.27 MB ]