Fundamentals of Steel Bridge Design, Part 1 (Self-Paced)

Lesson 1 of this course provides a basic introduction to steel-girder bridges, the bridge design and construction process, bridge steels, and the steel-girder bridge fabrication process.

 Topics to be covered in this lesson include the definition and discussion of basic steel-girder bridge components, including the superstructure, substructure, deck, bracing, field splices, web stiffeners, shear connectors, bearings, and joints. The design of all these components (except for substructures) will be covered in this course. The basics of the bridge design and construction process will be covered next from the preliminary design through final construction, followed by a detailed discussion of bridge steels, including product specifications (e.g., the various grades of steel that may be used in steel-girder bridges), the basics of the steel manufacturing process, the mechanical properties of steel (i.e., tensile strength, fracture toughness, fatigue resistance, ductility, residual stresses, hardness, etc.), and the corrosion resistance of steel.

Lesson 2 of this course covers the basics of bridge planning and layout.

 Topics to be covered in this lesson include a discussion on selecting the right bridge type. This topic will review the various steel-bridge types, including rolled-beam bridges, plate-girder bridges, tub-girder bridges, truss bridges, arch bridges, cable-stayed bridges, and suspension bridges. The discussion will include a description of each bridge type and where each bridge type is most efficiently and effectively used. Various factors that go into selecting the right steel-bridge bridge type will also be reviewed including span length considerations, constructability considerations, and other factors. Note that the primary focus of this course will be on rolled-beam and plate-girder type bridges. Next will be an introduction to stringer bridges (i.e., rolled-beam and plate-girder type bridges), including a discussion of some of the key preliminary design decisions that must be made for these types of bridges. These decisions include the determination of an appropriate span arrangement, the development of a reasonable framing plan (i.e., girder spacing, deck overhangs, field section sizes, and bracing spacing and configuration), and important I-girder proportioning considerations to arrive at a reasonable preliminary design of the beam or girder.

Lesson 3 is a companion to Steel Bridge Design handbook Volume 7 – Loads and Load Combinations and Volume 10 – Limit States. It begins by introducing the AASHTO Specifications and outlines the role it plays in bridge design. Focus is on loads for this lesson with the following topics:

 Introduction to AASHTO LRFD

•  Evolution of specifications
•  Reliability-based specifications
•  Loads, load factors, load modifiers
•  Load combinations and limit states
•  Review of influence lines
•  Sample load calculations

Lesson 4 of this course will focus on various aspects of selecting an appropriate level and method of analysis and demonstrating the application of loads and calculation of force effects using analytical models and code-specified analysis techniques. The lesson focuses on:

•  Review of common methods of analysis used in steel bridge design
• Determining an appropriate level and method of analysis
•  Demonstrating the use of simple and refined analysis models to obtain critical forces and displacements
• Applying various permanent and transient loads to analysis models
• Calculating distribution factors for steel beam bridges