The National Academies

NCHRP 22-41 [Completed]

Proposed Modification to AASHTO LRFD Bridge Design Specifications, Section 13—Railing

  Project Data
Funds: $230,000
Research Agency: Modjeski & Masters
Principal Investigator: Mr. John M. Holt
Effective Date: 6/6/2019
Completion Date: 8/31/2023
Comments: The final deliverables have been received. A publication decision is pending.

The language of "Section 13: Railing" of the AASHTO LRFD Bridge Design Specifications has not had a major revision since the load and resistance factor design (LRFD) specifications were adopted. Some of the text date back to the 1989 AASHTO Guide Specifications for Bridge Railings. Since that time, the Manual for Assessing Safety Hardware (MASH) has replaced NCHRP Report 350: Recommended Procedures for the Safety Performance Evaluation of Highway Features for evaluating safety hardware devices. A joint AASHTO/FHWA implementation agreement for MASH was signed on January 7, 2016 requiring all new permanent installation and full replacement of bridge rails on the national highway system in contracts letting after December 31, 2019 to be compliant to MASH.
Therefore, there is an immediate need to update the Section 13 of the AASHTO LRFD Bridge Design Specifications in order to incorporate the MASH requirements and address outdated language and areas of ambiguity particularly related to: loads, load distribution to bridge barriers and deck overhangs, and analysis methods for determining the demand and capacity of bridge barriers.
The objectives of this research were to (1) rewrite the entire "Section 13: Railing" of the AASHTO LRFD Bridge Design Specifications and (2) develop examples to demonstrate the application of the proposed rewritten section. The rewrite of Section 13  focused on new developments related to loading requirements of the AASHTO MASH and analysis methods for designing bridges to meet the MASH requirements.
STATUS: Completed

The final deliverable has been received. Apublication decision is pending.

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