This course gives a brief introduction to LRFD application to the design of Highway Bridge Superstructures. It will shed some light on the design philosophy of LRFD. It will show the Design truck loading and lane loading used for the design of the Superstructure. It will consider both concrete girder bridges and steel bridges. This course presents the theory, methodology, and application for the design and analysis of both steel and concrete highway bridge superstructures. The manual is based on the AASHTO LRFD Bridge Design Specifications, Seventh Edition, 2014, with Interim Revisions through 2015. Design examples and commentary throughout the manual are intended to serve as a guide to aid bridge engineers with the implementation of the AASHTO LRFD Bridge Design Specifications. This course consists of eight chapters. Chapter 1 provides an introduction to LRFD, including an overview of the LRFD design philosophy and a description of the various LRFD limit states. Chapter 2 provides general information about location features and design objectives, as well as a brief overview of Accelerated Bridge Construction. Chapter 3 presents loads and load factors, including design criteria for common bridge loads, as well as load factors used for various LRFD load combinations. Chapter 4 provides a general summary of structural analysis, including general analysis considerations, dead load analysis, live load analysis, and various methods of analysis. Chapter 5 provides valuable information for the design of concrete girder superstructures, including preliminary design decisions, flexural design of prestressed I-girders, design for shear and torsion, prestressing, and reinforcement details. Similarly, Chapter 6 provides valuable information for the design of steel girder superstructures, including LRFD girder verifications for constructibility, service, fatigue and fracture, flexure, and shear, as well as design provisions for various steel superstructure details. Chapter 7 describes decks and deck systems, covering such topics as traditional design method, empirical design method, deck overhang design, precast deck slabs, and bridge railings. Chapter 8 provides general information about bearings and joints, including design requirements for elastomeric bearings and pot bearings. Finally, a glossary of common terms related to bridge superstructures and LRFD is provided.
