2005 AASHTO BRIDGE COMMITTEE AGENDA ITEM: 40 (REVISION 2)

2005 AASHTO BRIDGE COMMITTEE AGENDA ITEM: 40 (REVISION 2)

SUBJECT: LRFD Bridge Design Specifications: Section 10 Replacement

TECHNICAL COMMITTEE: T-15 Foundations

REVISION ADDITION NEW DOCUMENT

DESIGN SPEC CONSTRUCTION SPEC MOVABLE SPEC

LRFR MANUAL OTHER

US VERSION SI VERSION BOTH

DATE PREPARED: 3/15/05

DATE REVISED: 6/30/05

AGENDA ITEM:

Replace all of Section 10 of the AASHTO LRFD Design Specifications with the attached new Section 10.

OTHER AFFECTED ARTICLES:

Article 3.11.8 (proposed as a separate agenda item).

Articles 5.7.4 and 5.13.4.5 (proposed agenda items by the T-10 committee).

There are references to the existing articles in Section 10 throughout other sections in the Third Edition. Each of

these references must be changed to a reference to the revised Section 10 which will require identifying the proper

article number with the proper engineering content. Attached is a list of affected articles in the Third Edition.

BACKGROUND:

States who have attempted to implement Section 10 of the AASHTO LRFD Design Specifications have had great

difficulty in doing so for one or more of the following reasons:

 The recommended procedures in the current Section 10 are not consistent with local and national

geotechnical design practice, including design practice as recommended in widely used FHWA manuals.

 The current LRFD Section 10 results in foundation designs that are considerably more conservative than

what would be required based on AASHTO Load Factor Design (i.e., the Standard Specifications).

 The current Section 10 specifies the use of out of date design methods.

 Resistance factors are not provided for certain aspects of foundation design.

 The current Section 10 is not clear on how to implement the procedures provided.

This rewrite of Section 10 is the result of an FHWA funded project that includes both specification updating and

the development of an updated NHI course on LRFD foundation and wall design. The rewrite is the result of a

collaborative effort between the consultant team hired by the FHWA and a Technical Working Group (TWG)

assembled to review and help develop the specifications and NHI course. This TWG consists of senior

geotechnical and structural engineers from several state DOT’s (WADOT, PENNDOT, VADOT, FLDOT,

OHDOT, CALTRANS – both the AASHTO T-15 Chair and Vice Chair were among these state representatives)

and the FHWA.

A draft rewrite of Section 10 was completed and sent out for a nationwide review in August 2004 for a 3 month