Experimental investigation on cyclic behavior of coastal bridge piers with non-uniform corrosion under biaxial quasi-static loads

Corrosion-induced damage on coastal bridge piers reduces the seismic performance of structures. Biaxial earthquake excitation makes the degradation even worse. In this study, cyclic tests of four corroded bridge piers with different levels of non-uniform corrosion damage along the elevation were conducted under biaxial pseudo-static cyclic loads, while another corroded bridge pier was applied with only a uniaxial load for comparison. First, the experimental program, including the specimen design, accelerated corrosion in laboratory, test facility, measurement instrument, and loading protocol, is introduced. Then, based on the test results, the experimental observations, hysteretic characteristics, strength, ductility, curvature distribution, and energy dissipation of the specimens are analyzed to investigate the effects of the corrosion degree and biaxial horizontal loading condition. The test results indicate that the seismic performance of bridge piers is strongly affected by biaxial horizontal loads, and the increase in local damage due to non-uniform corrosion makes the performance deterioration more severe.