Bridge Design Manual - LRFD (LRF)
Bridge Design Manual - LRFDRevised January 2020 2020 by Texas Department of Transportation(512) 463-8630 all rights reserved
Manual Notice 2020-1From:Graham Bettis, P.E., Director, Bridge DivisionManual:Bridge Design Manual - LRFDEffective Date: January 01, 2020PurposeThis manual documents policy on bridge design in Texas. It assists Texas bridge designers inapplying provisions documented in the AASHTO LRFD Bridge Design Specifications, to whichdesigners should adhere unless directed otherwise by this document.ChangesUpdates consist of the following: Chapter 1 includes the deletion of the Revision History Table.Chapter 2 is updated to include the Extreme Event III loading combination which relates tostructural member or component failure. An additional section is added to Chapter 3, SystemRedundancy Evaluation for Steel Twin Tub Girders, requiring all newly steel twin tub girderbridges to be designed for system redundancy.SupersedesThis revision supersedes version 2018-1.ContactFor more information about any portion of this manual, please contact the Design Section Directorof the Bridge Division.ArchivesPast Manual notices are available in a PDF archive.
Table of ContentsChapter 1 — About this ManualSection 1 — Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Implementation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Purpose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Organization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Feedback . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-21-21-21-21-3Chapter 2 — Limit States and LoadsSection 1 — Limit States . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Importance Factor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Redundancy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Extreme Event Limit States . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Multi-column Bridges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Live Load Deflection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Section 2 — Loads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Live Loads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Braking Force . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Vehicular Collision Force . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Earthquake Effects. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Vessel Collision . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Pedestrian . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-22-22-22-22-32-32-42-42-42-42-52-52-6Chapter 3 — Superstructure DesignSection 1 — Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Section 2 — Concrete Deck Slabs on I-Girders, U-Beams, Spread Box Beams, Spread Slab Beams, Steel Plate Girders, and Steel Tub Girders . . . . . . . . . . . . . . . . . .Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Geometric Constraints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Design Criteria. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Detailing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Section 3 — Concrete Deck Slabs on Adjacent-Framed Beams (Slab Beams and Box Beams) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Geometric Constraints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Design Criteria. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Detailing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Section 4 — Pretensioned Concrete I Girders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Bridge Design Manual - LRFDi3-23-23-33-33-33-43-43-53-53-53-53-63-7TxDOT 1/2020
Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-7Geometric Constraints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-7Structural Analysis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-7Design Criteria. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-8Section 5 — Pretensioned Concrete U Beams. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-11Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-11Geometric Constraints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-11Structural Analysis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-11Design Criteria. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-12Detailing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-12Section 6 — Pretensioned Concrete Slab Beams. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-13Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-13Geometric Constraints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-13Structural Analysis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-13Design Criteria. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-14Section 7 — Pretensioned Concrete Spread Slab Beams . . . . . . . . . . . . . . . . . . . . . . . . . . 3-15Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-15Geometric Constraints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-15Structural Analysis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-15Design Criteria. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-16Section 8 — Pretensioned Concrete Decked Slab Beams . . . . . . . . . . . . . . . . . . . . . . . . . . 3-17Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-17Section 9 — Pretensioned Concrete Box Beams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-19Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-19Geometric Constraints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-19Structural Analysis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-19Design Criteria. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-20Section 10 — Pretensioned Concrete Spread Box Beams (X-Beams) . . . . . . . . . . . . . . . . 3-21Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-21Geometric Constraints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-21Structural Analysis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-21Design Criteria. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-22Section 11 — Cast-in-Place Concrete Slab and Girder Spans (Pan Forms) . . . . . . . . . . . . 3-23Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-23Geometric Constraints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-23Structural Analysis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-23Design Criteria. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-23Section 12 — Cast-in-Place Concrete Slab Spans . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-24Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-24Bridge Design Manual - LRFDiiTxDOT 1/2020
Geometric Constraints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Structural Analysis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Design Criteria. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Section 13 — Straight Plate Girders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Geometric Constraints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Structural Analysis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Design Criteria. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Section 14 — Curved Plate Girders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Geometric Constraints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Structural Analysis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Design Criteria. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Section 15 — Segmental Spans . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Geometric Constraints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Structural Analysis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Design Criteria. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Detailing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Section 16 — Spliced Precast Girders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Geometric Constraints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Section 17 — System Redundancy Evaluation for Steel Twin Tub Girders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Structural Analysis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Design Criteria. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Detailing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-43Chapter 4 — Substructure DesignSection 1 — Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Section 2 — Foundations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Guidance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Section 3 — Abutments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Geometric Constraints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Design Criteria. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Section 4 — Rectangular Reinforced Concrete Bent Caps . . . . . . . . . . . . . . . . . . . . . . . . . .Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Bridge Design Manual - LRFDiii4-24-24-34-34-44-44-44-44-64-6TxDOT 1/2020
Geometric Constraints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-6Structural Analysis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-6Design Criteria. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-6Detailing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-7Section 5 — Inverted Tee Reinforced Concrete Bent Caps. . . . . . . . . . . . . . . . . . . . . . . . . . 4-8Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-8Geometric Constraints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-8Structural Analysis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-8Design Criteria. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-8Detailing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-9Section 6 — Columns for Multi-Column Bents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-10Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-10Geometric Constraints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-10Structural Analysis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-10Design Criteria. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-11Detailing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-11Column Collision. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-11Section 7 — Columns for Single Column Bents or Piers . . . . . . . . . . . . . . . . . . . . . . . . . . 4-12Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-12Geometric Constraints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-12Structural Analysis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-12Design Criteria. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-12Detailing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-12Column Collision. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-12Section 8 — Post-Tensioned Concrete Bent Caps. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-14Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-14Geometric Constraints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-14Structural Analysis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-14Design Criteria. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-15Detailing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-15Section 9 — Lateral Restraint of Bridge Superstructures on Substructure . . . . . . . . . . . . . 4-17General. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-17Bridges Crossing Water Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-17I-Girder Bridges. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-17U-Beam Bridges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-17Spread Slab Beam and Spread Box Beam (X-beam) Bridges. . . . . . . . . . . . . . . . . . . . . . 4-17Slab Beam, Box Beam, Decked Slab Beam, and Double-Tee Beam Bridges. . . . . . . . . . 4-18Steel Beam or Girder Bridges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-18Bridge Design Manual - LRFDivTxDOT 1/2020
Chapter 5 — Other DesignsSection 1 — Widenings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Design Recommendations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Section 2 — Steel-Reinforced Elastomeric Bearings for Pretensioned Concrete I-Girders .Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Geometric Constraints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Structural Analysis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Design Criteria. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Detailing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Section 3 — Strut-and-Tie Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Structural Analysis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Design Criteria. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-25-25-35-35-35-35-45-45-55-55-5Section 4 — Corrosion Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Guidance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Section 5 — Concrete Culverts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Geometric Constraints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Structural Analysis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Design Criteria. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Detailing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-65-65-75-75-75-75-75-8Chapter 6 — Archiving Design NotesSection 1 — Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Section 2 — Procedure for Archiving Design Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Scan Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Naming Convention. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Delivering the File . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-26-26-36-36-46-4Bridge Design Manual - LRFDvTxDOT 1/2020
Chapter 1 — About this ManualContents:Section 1 — IntroductionBridge Design Manual - LRFD1-1TxDOT 01/2020
Chapter 1 — About this ManualSection 1 — IntroductionSection 1 — IntroductionImplementationLoad and Resistance Factor Design (LRFD) is a design methodology that makes use of load andresistance 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 thefirst AASHTO Load and Resistance Factor Bridge Design Specifications. The Federal HighwayAdministration (FHWA) mandated the use of LRFD for all bridges for which the Texas Departmentof Transportation (TxDOT) initiated preliminary engineering after October 2007.PurposeThis manual documents policy on bridge design in Texas. It assists Texas bridge designers inapplying provisions documented in the AASHTO LRFD Bridge Design Specifications, 2017, 8thEdition, which designers should adhere to unless directed otherwise by this document.All Articles, Equations, and Tables referenced in this manual are from the current AASHTO LRFDBridge Design Specifications, unless noted otherwise.OrganizationThe information in this manual is organized as follows: Chapter 1, About this Manual. Introductory information on the purpose and organization of themanual. Chapter 2, Limit States and Loads. General information on limit states and on load factors. Chapter 3, Superstructure Design. Policy on LRFD design of specific bridge superstructurecomponents. Chapter 4, Substructure Design. Policy on LRFD design of specific bridge substructurecomponents. Chapter 5, Other Designs. Design guidelines for bridge widenings, steel-reinforcedelastomeric bearings for pretensioned concrete beams, strut-and-tie method, and culverts. Thischapter also addresses corrosion protection measures. Chapter 6, Archiving Design Notes. Policy for archiving bridge design notes in TxDOT’sbridge inspection database management system.Bridge Design Manual - LRFD1-2TxDOT 01/2020
Chapter 1 — About this ManualSection 1 — IntroductionFeedbackDirect any questions or comments on the content of the manual to the Director of the BridgeDivision, Texas Department of Transportation.Bridge Design Manual - LRFD1-3TxDOT 01/2020
Chapter 2 — Limit States and LoadsContents:Section 1 — Limit StatesSection 2 — LoadsBridge Design Manual - LRFD2-1TxDOT 01/2020
Chapter 2 — Limit States and LoadsSection 1 — Limit StatesSection 1 — Limit StatesImportance FactorClassify all bridge designs as typical bridges when applying the operational importance factor, ηI,to strength limit states. Use ηI 1.0 for all limit states. See Article 1.3.5.RedundancyAdd the following to Article 1.3.4 as follows:ηR 1.05 for nonredundant members and members requiring an analysis to establish systemredundancy.Extreme Event Limit StatesRevise the following definition in Article 1.2 as follows:Extreme Event Limit States—Limit states relating to events such asearthquakes, ice load, structural member or component failure, andvehicle and vessel collision, with return periods in excess of thedesign life of the bridge.Revise Article 1.3.2.5 as follows:Extreme Event Limit States - The extreme event limit state shall betaken to ensure the structural survival of a bridge during a majorearthquake or flood, or when collided by a vessel, vehicle, or iceflow, possibly under scoured conditions, or after failure of astructural member or component.Extreme Event I and IIProvisions under Extreme Event I need not be considered except for regions near Big Bend asnoted in the subsequent section on Earthquake Effects.Provisions under Extreme Event II must be considered only when vehicular collision or vesselcollision evaluation is required.Extreme Event IIISupplement Article 3.4.1 with the following:Bridge Design Manual - LRFD2-2TxDOT 01/2020
Chapter 2 — Limit States and Loads Section 1 — Limit StatesExtreme Event III - Load combination relating to a structuralmember or component failure.Supplement Table 3.4.1-1 with the following:LoadCombinationLimit StateExtremeEvent IIIUse One of These at a 0Supplement Table 3.4.1-2 with the following:Type of Load, Foundation Type, and Method Used to Calculate DowndragDC: Components and Attachments for the evaluation of system redundancy asspecified in Chapter 3, Section 17, for Extreme Event III onlyLoad FactorMaximum1.10Minimum0.90All load effects during an assumed fracture event due to both permanent and assumed transient loads shall be amplified by a factorof 1.20 to simulate the dynamic effects of a fracture on the twintub girder span(s).Multi-column BridgesFor typical multi-column bridges, determine design loads for foundations at Service I LoadCombination. Determine foundation loads for single column bents and other non-typicalsubstructures using Service I and Service IV Load Combinations. For Service IV LoadCombination, include the vertical wind pressure as specified in Article 3.8.2. For foundation loadson typical multi-column bents and abutments, use the multiple presence factor, m, per Article3.6.1.1.2. Distribute the live load equally to all supporting foundations, assuming all lanes areloaded. Do not apply the Dynamic Load Allowance (IM) to the live load in determining foundationloads when the foundation elements are entirely below ground level.Live Load DeflectionCheck live load deflection using Articles 2.5.2.6.2 and 3.6.1.3.2. Ensure that the calculateddeflection does not exceed Span/800 using a live load distribution factor equal to number of lanesdivided by number of girders. If the bridge has pedestrian sidewalks, the deflection limit is Span/1000.Bridge Design Manual - LRFD2-3TxDOT 01/2020
Chapter 2 — Limit States and LoadsSection 2 — LoadsSection 2 — LoadsLive LoadsUse HL93 design live load as described in Article 3.6.1.2 unless design for a special vehicle isspecified or warranted.Design widenings for existing structures using HL93. Rate existing structures using Load FactorRating per the current AASHTO Manual for Bridge Evaluation and HS20 loading. Show load rat
Manual Notice 2020-1 From: Graham Bettis, P.E., Director, Bridge Division Manual: Bridge Design Manual - LRFD Effective Date: January 01, 2020 Purpose This manual documents policy on bridge desig
Recently, we were made aware of some technical revisions that need to be applied to the AASHTO LRFD Bridge Design Specifications, 6th Edition. Please replace the existing text with the corrected text to ensure that your edition is both accurate and current. AASHTO staff sincerely apologizes for any inconvenience.File Size: 2MBPage Count: 104Explore furtherAASHTO LRFD 2012 Bridge Design Specifications 6th Ed ( US .archive.orgAASHTO Issues Updated LRFD Bridge Design Guideaashtojournal.orgAASHTO Publishes New Manual for Bridge Element Inspection .aashtojournal.orgAASHTO LRFD Bridge Design Specifications. Eighth Edition .trid.trb.orgSteel Bridge Design Handbook American Institute of Steel .www.aisc.orgRecommended to you b
AASHTO LRFD Bridge Design Specifications, 4th Edition, with 2009 interims AASHTO LRFD Bridge Design Specifications, 5th Edition AASHTO LRFD Bridge Design Specifications, 5th Edition, with 2010 interims AASHTO LRFD Bridge Design Specifications, 6th Edition AASHTO LRFD Bridge Design
AASHTO LRFD Bridge Design Specifications, 8th Edition (LRFD-8) May 2018 . Dear Customer: Recently, we were made aware of some technical revisions that need to be applied to the AASHTO LRFD Bridge Design Specifications, 8th Edition. Please scroll down to see the full erratum.File Size: 2MB
FHWA/NHI Bridge Design and Analysis Courses (www.nhi.fhwa.dot.gov) NHI Course 130081: LRFD for Bridge Superstructures NHI C 130082NHI Course 130082: LRFD f B id S b t t d ERSLRFD for Bridge Substructures and ERS NHI Course 130092: LRFR for Highway Bridges NHI Course 130093: LRFD Seismic Analysis and Design of Bridges NHI Course 130094: LRFD Seismic Analysis and Design of Tunnels,
MAY 2016 LRFD BRIDGE DESIGN 8-3 AASHTO LRFD shall be obtained from the National Design Specification for Wood Construction (NDS). The AASHTO LRFD tabulated design values assume dry-use conditions. These tabulated values shall be modified if wood will be subject to wet use conditions. Table 8.1.1.1. has an abbreviated list of some typical
AASHTO LRFD Bridge Design Specifications, 7th Edition, 2014 (AASHTO LRFD) v. AASHTO LRFD Specifications for Structural Supports for Highway Signs, Luminaires, and Traffic Signals, First Edition, 2015 (AASHTO Signs) vi. Washington State Department of Transportation Bridge Design Manual (LRFD), 2016 (BDM) vii. American Institute of Steel .
designed by the latest edition of AASHTO LRFD Bridge Design Specifications. Designs for the reconstruction or rehabilitation of existing bridge structures should be completed with guidance from the Bridge Design Engineer. This manual documents policy on LRFD bridg
Academic literary criticism prior to the rise of “New Criticism” in the United States tended to practice traditional literary history: tracking influence, establishing the canon of major writers in the literary periods, and clarifying historical context and allusions within the text. Literary biography was and still is an important interpretive method in and out of the academy; versions of .
