Load and Resistance Factors for Earth Pressures on Bridge Substructures and Retaining Walls

The objective of NCHRP Project 12-55, now completed, was to develop recommended load and resistance factors for foundations and retaining walls for possible inclusion in the AASHTO LRFD Bridge Design Specifications using reliability theory. Lateral, vertical, and surcharge earth loads were investigated. Data for use in developing the statistical parameters needed to conduct these analyses were gathered under NCHRP 12-55, and reliability analyses were conducted to estimate load and resistance factors for various strength limit states that incorporate vertical or lateral earth loads. Nevertheless, the statistical parameters used in the calibration process were not documented consistent with recently developed standards (e.g., TRB Circular E-C079). Also, it is not clear that the existing data are adequate to achieve valid calibration of earth load and resistance factors. The objective of the research is to evaluate the data gathered under NCHRP 12-55 and other sources identified herein and assess the adequacy of that data to develop recommended load and resistance factors for foundations and retaining walls for the AASHTO LRFD Bridge Design Specifications.

• Record URL:
  http://www.trb.org/TRBNet/ProjectDisplay.asp?ProjectID=342

Language

• English

Project

• Status: Completed
• Funding: $97700.00
• Contract Numbers:

  Project 12-55A

• Sponsor Organizations:

  American Association of State Highway and Transportation Officials (AASHTO)

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

  Transportation Research Board

  500 Fifth Street, NW
  Washington, DC  United States  20001

  National Cooperative Highway Research Program

  Transportation Research Board
  500 Fifth Street, NW
  Washington, DC  United States  20001
• Project Managers:

  Beal, David

• Performing Organizations:

  Prototype Engineering, Incorporated

  ,    
• Principal Investigators:

  Christian, John

• Start Date: 20060710
• Expected Completion Date: 0
• Actual Completion Date: 20070709
• Source Data: RiP Project 12342

Subject/Index Terms

• TRT Terms: Bridge design; Bridge substructures; Data collection; Earth pressure; Foundations; Loads; Research projects; Resistance (Mechanics); Retaining walls
• Identifier Terms: National Cooperative Highway Research Program
• Subject Areas: Bridges and other structures; Data and Information Technology; Research; I30: Materials;

Filing Info

• Accession Number: 01460505
• Record Type: Research project
• Source Agency: National Cooperative Highway Research Program
• Contract Numbers: Project 12-55A
• Files: RiP
• Created Date: Jan 3 2013 1:26PM