NCHRP 12-55A [Completed]
Load and Resistance Factors for Earth Pressures on Bridge Substructures and Retaining Walls
| Project Data
||Prototype Engineering, Inc.|
Background: 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.
Objective: 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.
Status: The available data were determined to be inadequate for the intended use. The project has been canceled. No report.
Products Availability: There are no products of this project available for distribution.