Lack of as-built information for bridges and culverts is a problem that many state departments of transportation (DOTs) are facing across the nation. Analytical load-rating of bridges and culverts can only be successfully performed with complete information of the structure’s as-built composition. When missing as-built information, conservative assumptions are often used, which can result in load postings with economic and logistical implications. There is uncertainty about the level of uniformity in the way different DOTs approach the problem of load rating the structures with missing or incomplete plans.
In a recent survey, the majority of surveyed states reported more than 100 bridges with missing plans in their inventory. In some of the surveyed states, bridges with missing as-built plans exceed 25% of the total bridge inventory. The methods used to obtain missing information vary significantly between different jurisdictions. Employed methods range from diagnostic and/or proof load testing, using engineering judgement, a range of non-destructive testing techniques to determine materials and geometrical properties, to utilizing conservative assumptions.
The objective of this synthesis is to document current practices for load rating of bridges and culverts with missing or incomplete as-built plans used by DOTs.
Information to be gathered includes but is not be limited to:
• Techniques used by DOTs for load rating of bridges with missing or incomplete as-built plans including
o engineering judgement based on, but not limited to, assessment of
primary load-carrying components
- physical condition
- historical design parameters
- loading history
- maintenance and/or repair history
o non-destructive evaluation
o load testing
o other techniques
• Load rating practices according to the bridge type and/or jurisdiction (e.g. city, county, state)
• Current practice for the consideration of decks and substructures in load rating
• Condition-specific strategies for load rating bridges and culverts with missing as-built plans
• Commonly missing information from incomplete as-builts that hinders load rating
Information will be collected through a literature review, a survey of DOTs (possibly through the AASHTO Committee on Bridges and Structures) and follow-up interviews with selected agencies for the development of case examples. Information gaps and suggestions for research to address those gaps will be identified.
Biniam Aregawi, Texas DOT
Darrin Beckett, Kentucky Transportation Cabinet
Benjamin W. Foster, Maine DOT
Spencer Koehler, Illinois DOT
Mary Smith, Montana DOT
Timothy R.B. Taylor, University of Kentucky
Yi Edward Zhou, AECOM
Tuonglinh "Linh" Warren, Federal Highway Administration
Stephen F. Maher, Technical Activities Division
First meeting: September 25, 2019, Washington, DC
Second meeting: June 19, 2020