Chapter 3: Design Specifications
Anchor: #i999319Section 1: Mandatory Specifications
Anchor: #i999324Overview
There are many specifications available that have a bearing on the design of bridges and other highway structures. This section identifies those specifications that the Texas Department of Transportation (TxDOT) considers mandatory for use.
Anchor: #i999334AASHTO Standard Specifications for Highway Bridges
The Standard Specifications for Highway Bridges adopted by the American Association of State Highway and Transportation Officials (AASHTO) is the most important control over bridge design. It is usually published in full every four years. In the intervening years, Interim Specifications are distributed, which contain the revisions approved on a ballot following the last meeting of the AASHTO Highway Subcommittee on Bridges and Structures. The Federal Highway Administration (FHWA) may, at any time, review designs and details for compliance with these specifications for projects using federal money.
NOTE: Although these specifications are considered mandatory, a few deviations are made based on long-time local practice or research.
Copies of these specifications, as well as other AASHTO publications, may be purchased from AASHTO by calling 1-800-231-3475, or at their website at http://www.transportation.org/.
Anchor: #i999360AASHTO Standard Specifications for Structural Supports for Highway Signs, Luminaires and Traffic Signals (D1.1)
Standard Specifications for Structural Supports for Highway Signs, Luminaires and Traffic Signals is also published by AASHTO. This specification contains a more comprehensive treatment of wind effects on structures.
Anchor: #i999370ANSI/AASHTO/AWS Bridge Welding Code (D1.5)
The American National Standards Institute (ANSI)/AASHTO/American Welding Society (AWS) Bridge Welding Code combines the recommendations of the three agencies with regard to welding details, methods, and quality tests. Bridge design is no better than the details that are generated, and structural steel is particularly detail oriented because of fatigue considerations.
Anchor: #i999380AREMA Specifications
The American Railway Engineering and Maintenance-of-Way Association (AREMA) Specifications cover many aspects of railway engineering, including the design of bridges and culverts that carry railway traffic.
Anchor: #i999390Individual Railroad Company Requirements
Individual railway companies may have their own supplemental requirements, which should be investigated for each project.