Simplified Inelastic Design of Steel Girder Bridges

Abstract

Inelastic design of steel girder bridges can result in beneficial material and fabrication cost savings and reduce the susceptibility of steel girder bridges to fatigue. The ability to redistribute large negative region moments, coupled with section capacities exceeding the yield moment, results in an efficient structure used to its limit-state capacity. Proposed LRFD inelastic design provisions are presented that allow compact or noncompact pier sections resulting in consistent bridge design across the steel girder bridge inventory. This paper illustrates the simplified inelastic design provisions, presents an example design of a two-span composite bridge comprising noncompact sections at the pier, and summarizes the experimental verification of the example design. The proposed inelastic design procedures are simple to apply, removing the cumbersome continuity and iterative requirements of past inelastic design practice.