Local Strain Behaviors During Earthquakes from Low-Cycle Fatigue Assessment of High-Strength Steel Bridge Piers

Abstract

The objective of this research is to study the behavior of local strain in steel bridge piers under earthquake conditions. This research focuses on the analysis of major earthquakes in Japan and Thailand by comparing the performance of steel bridge piers made of normal strength steel and high-strength steel. It was found that steel bridge piers suffered from low-cycle fatigue damage in the large plastic region. The severity of such damage was assessed by using the Finite Element Method (FEM) with the concept of Effective Notch Strain introduced by the International Institute of Welding (IIW). The result indicates that earthquake waves result in higher local strain, strain rate, and plastic strain energy in steel bridge piers made of high-strength steel than steel bridge piers made of normal strength steel. In addition, high-strength steel has a smaller yielding area compared to normal strength steel. Therefore, the yielding energy per area index should be considered to confirm the mode of failure of high-strength steel bridge piers.