Synthesis of Information Related to Highway Practices. Topic 53-06. Local Calibration of LRFD Geotechnical Resistance Factors

The load and resistance factor design (LRFD) framework for foundations of bridges and other structures provides the advantage to adapt and improve resistance factors - other than those generally prescribed in the code - based on local geology, design practice, and construction practice through statistics and reliability analysis. The codified AASHTO LRFD resistance factors were developed based on load tests conducted across the country, with variable conditions and practices. This approach, while allowing broad applicability, results in comparatively large coefficients of variation and conservative resistance factors. While many state departments of transportation (DOTs) use these codified resistance factors, other agencies have invested in evaluation of local geology and local design practice, and have established and adopted resistance factors for these specific design or construction practices. State DOTs have used different methods to locally calibrate various resistance factors associated with different design methodologies or foundation construction control. The objective of this synthesis is to document the extent to which state DOTs have developed local resistance factor calibration, which factors have been calibrated, and how locally calibrated factors have been used. Information to be gathered includes (but is not limited to): (1) Extent to which state DOTs have developed local resistance factor calibration; (2) Factors calibrated; (3) Uses of locally calibrated factors; (4) Performance monitoring and load testing techniques used; (5) Local calibration of shallow foundation design methods; (6) Local calibration of deep foundation design methods; (7) Local calibration of deep foundation construction methods; (8) Methods used for the exchange of data associated with site investigation and characterization of foundation performance testing; and (9) Risks and obstacles identified by state DOTs for local resistance factor calibration. Information will be gathered through a literature review, a survey of state DOTs, 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.

Language

  • English

Project

  • Status: Active
  • Funding: $45000
  • Contract Numbers:

    Project 20-05, Topic 53-06

  • Sponsor Organizations:

    National Cooperative Highway Research Program

    Transportation Research Board
    500 Fifth Street, NW
    Washington, DC  United States  20001

    American Association of State Highway and Transportation Officials (AASHTO)

    444 North Capitol Street, NW
    Washington, DC  United States  20001

    Federal Highway Administration

    1200 New Jersey Avenue, SE
    Washington, DC  United States  20590
  • Project Managers:

    Gause, Jo

  • Start Date: 20210524
  • Expected Completion Date: 0
  • Actual Completion Date: 0

Subject/Index Terms

Filing Info

  • Accession Number: 01771594
  • Record Type: Research project
  • Source Agency: Transportation Research Board
  • Contract Numbers: Project 20-05, Topic 53-06
  • Files: TRB, RIP
  • Created Date: May 17 2021 3:14PM