Seismic Evaluation of Multi-Span Reinforced Concrete Bridges with Ultra High-Performance Concrete Piers Using Fragility Curves

Document Type : Original Article


Department of Civil Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran


Bridges play a vital role in transportation, traffic management, and providing access to strategic locations, especially during crises. Earthquakes are unpredictable events that disrupt critical transportation routes and damage important structures. Innovative technologies, such as Ultra High-Performance Concrete (UHPC), offer hope for enhancing structural flexibility and reducing damage. UHPC, known for its uniformity, low permeability, and durability, increases the resistance of bridges to seismic forces and limits the spread of damage. One of the most effective methods for assessing seismic vulnerability is Fragility Analysis. This study evaluates urban bridges with UHPC concrete columns supporting cast-in-place concrete T-beam superstructures. The analysis was conducted using CSI Bridge software, and appropriate ground motion records were selected for Incremental Dynamic Analysis (IDA) and damage level calculations. The results indicate that the probability of damage exceeding a certain threshold in UHPC concrete piers is lower compared to those made of ordinary concrete. Examining damage intensity levels reveals that high-performance concrete improves performance by 7% in the worst-case scenario and up to 26% in the best-case scenario compared to ordinary concrete.