Task 132, FY 2001, "Final Review and Acceptance of LRFD Specification for Walls" (Barry Christopher). The AASHTO Bridge Design Specifications were published and put into use in 1994. The second edition of these specifications was published in 1998, and since then, the 1999 interim's have been published as the latest revision. Section 3 (especially Article 3.11) and Section 11 contain the current LRFD specifications for lateral earth pressures and retaining wall design. In 1997 and 1998, the AASHTO standard specifications, Sections 5 and 7, were mostly rewritten. The LRFD specifications on retaining walls needed to be rewritten to reflect those changes. NCHRP project 20-07, Task 88, was conducted to perform the necessary calibrations to convert the allowable stress design specifications to LRFD specifications to reflect the calibration work as well as the changes to the AASHTO Standard Specifications on retaining walls done in 1997 and 1998. A calibration report and draft specification changes to Sections 3 and 11 were completed. The task that remained was to implement those products into the AASHTO LRFD specifications. Additional review by selected members of the AASHTO Highway Subcommittee on Bridges and Structures (HSCOBS), as well as outside engineers and wall industry representatives, was needed before final submission as an agenda item for the HSCOBS annual meeting in 2001.
The objective of this task was to prepare final recommended revisions to Sections 3 and 11 of the AASHTO LRFD Bridge Design Specifications. This project is completed. Copies of the recommended specifications have been delivered to the AASHTO Highway Subcommittee on Bridges and Structures for consideration (NCHRP Staff: D.B. Beal)