Effects of Track Structure on Seismic Behavior of Isolation System Bridges

Abstract

This study examines how systems to isolate and protect railroad bridges during earthquakes can be affected by the behavior of track under seismic stresses. The need for high performance of railway structures under such stresses is explained as justification for base isolation designs to reduce and dampen acceleration and displacement during an earthquake. Past efforts to study the complexity of the relationship between track and bridge structures are noted. This study addresses the behavior of track structures with direct fastenings, widely used, especially for the Shinkansen trains. Shake table tests are used to demonstrate track behavior. The design of the experiment is given, along with detailed measures from shake table results. After simulation of seismic forces on certain ground configurations, results indicate that track structure plays a role in the overall stability of the bridge structure and needs additional study for proper measures to be designed.