Seismic fragility analysis of highway bridges in India considering evolution of seismic code provisions—a case study

Abstract

Periodic advances in seismic design codes, and bridge detailing and construction practices across different nations are a common manifestation of the lessons learned from past earthquakes. The structural deficiencies are addressed in prevailing design standards through improved estimates of seismic forces and reinforcement detailing to better withstand the next seismic event. Similarly, a history of damaging earthquakes in the Indian subcontinent has led to significant upgradation in provisions of seismic code for highway bridge design. Bridges designed as per such varied design methods must be evaluated for vulnerability estimation for future earthquakes. However, there is a marked absence of such seismic vulnerability evaluation frameworks for highway bridges within the country. The present study investigates the impact of seismic code provisions on seismic performance and probability of failure using fragility curves. Significant improvement in performance is observed compared to non-seismic design for the case-study bridge when seismic design principles are adopted.