Seismic Vulnerability Assessment of a Multi-Span Continuous Steel-Girder Bridge Isolated by SMA Wire-Based Natural Rubber Bearings (SMA-NRB)

Abstract

Seismic base isolation is one of the most efficient ways to protect structures (e.g. buildings or bridges) from disastrous effects of earthquakes. Base-isolated structures are mostly being designed and constructed in developed countries such as United States, Italy, Japan, and New Zealand. In order to extend such applications to developing countries, new techniques are introduced by reducing the cost and improving the performance of earthquake protective systems. In this regard, advanced materials such as shape memory alloys (SMA) are implemented into base isolation mechanisms (e.g. elastomeric bearings) and efficient manufacturing processes are developed. When a new generation of smart elastomeric isolator is introduced, it is critical to assess its seismic performance under different ground motions. The goal of this study is to evaluate the seismic fragility of a multi-span continuous steel-girder bridge isolated by SMA wire-based natural rubber bearings (SMA-NRBs). Results show that equipping natural rubber bearing (NRB) with SMA wires decreases the probability of damage of the bridge. It means that the bridge system becomes less fragile when NRB is fitted with SMA wires.