A U.S. phenomenon: Tall, Slender Bridge Rocker Bearings

摘要

Bridge rocker bearings are relatively small structural components that support the gravity loads of bridge superstructures and, by tilting, accommodate longitudinal thermal expansion and contraction of the superstructures without imposing stresses into the substructure and foundation. Short and stocky rocker bearings were first introduced into railroad bridges in the last third of the nineteenth century in Germany and the U.S. In the late 1880s, soon after these rocker bearings were in use, several engineers published articles (for example [1]) about the tendency for these bearings to excessively tilt, become unstable, and topple over, thus collapsing bridge spans. There is some evidence that failed railroad bridges were either abandoned or re-built.