Chapter 1: About this Manual
Section 1: Introduction
Implementation
Load and Resistance Factor Design (LRFD) is a design methodology that makes use of load and resistance factors based on the known variability of applied loads and material properties. In 1994, the American Association of State Highway and Transportation Officials (AASHTO) published the first
AASHTO Load and Resistance Factor Bridge Design Specifications
. The Federal Highway Administration (FHWA) mandated the use of LRFD for all bridges for which the Texas Department of Transportation (TxDOT) initiated preliminary engineering after October 2007.Purpose
The purpose of this manual is to document policy on bridge design in the state of Texas. It assists Texas bridge designers in applying provisions documented in the
AASHTO LRFD Bridge Design Specifications, 2020, 9th Edition
, which designers should adhere to unless directed otherwise by this document. The following manuals and guides should be used in companion with this document for designing bridges in Texas.- Bridge Design Guide
- Bridge Detailing Guide
- Bridge Railing Manual
- Bent (Pier) Protection Guide
- Bridge Project Development Manual
- Bridge Inspection Manual
- Geotechnical Manual-LRFD
- Hydraulic Design Manual
- Quality Control and Quality Assurance Guide
- TxDOT Preferred Practices for Steel Bridge Design, Fabrication, and Erection
All Articles, Equations, and Tables referenced in this manual are from the
Edition of AASHTO LRFD Bridge Design Specifications, unless noted otherwise.
Edition of AASHTO LRFD Bridge Design Specifications, unless noted otherwise.
Organization
The information in this manual is organized as follows:
- Chapter 1, About this Manual. Introductory information on the purpose and organization of the manual.
- Chapter 2, Limit States and Loads. General information on limit states and load factors.
- Chapter 3, Superstructure Design. Policy on LRFD design of specific bridge superstructure components.
- Chapter 4, Substructure Design. Policy on LRFD design of specific bridge substructure components.
- Chapter 5, Other Designs. Design guidelines for various miscellaneous design aspects including bridge widenings, steel-reinforced elastomeric bearings for pretensioned concrete beams, strut-and-tie method, corrosion protection, culverts, non-contact lap splices, and bridge load rating for new structures.
- Chapter 6, Archiving Design Notes. Policy for archiving bridge design notes in TxDOT’s bridge inspection database management system.
Feedback
Direct any questions or comments on the content of the manual to the Director of the Bridge Division, Texas Department of Transportation.