Monotonic and Cyclic Moment-Inelastic Rotation Behavior for Inelastic Design of Steel Girder Bridges

Abstract

Inelastic design of steel girder bridges offers flexibility for innovative bridge structures. The moment-inelastic rotation behavior of interior pier sections is the most important and also the most confusing aspect of the design process. This moment-rotation relation and how it pertains to the service and strength limits of inelastic design are presented. The results of a family of four girder component tests with various properties and expected behaviors are compared with those obtained with theoretical moment-inelastic rotation design models. The fourth of these was subjected to rigorous simulated moving load tests to examine variable repeated loadings. The experimental results matched those obtained with the design models in behavior, and the test moment capacities at the various design levels exceeded those that were predicted. The moving load test showed no degradation of stiffness or strength compared to monotonic loading tests.