Quasi-Static Tests and Simulations of Round-Ended Railway Bridge Piers with a Small Shear-Span Ratio

Abstract

This study investigates the seismic performance of round-ended railway bridge piers subjected to transverse bridge loading. Six scaled models of bridge piers with low-reinforcement ratios, low axial compression ratios, and low shear-span ratios were designed and fabricated. Quasi-static tests were conducted on these models to analyze their seismic response. The study clarifies the seismic damage mechanisms and examines the bearing capacity, displacement ductility, stiffness degradation, residual displacement, and hysteresis energy dissipation of the bridge piers. Key parameters influencing seismic performance were identified. OpenSEESpy (version 3.2.2.9) fiber and ABAQUS (version 2021) internship models were also constructed to simulate the bridge pier test process. The research results are as follows: (1) small shear-span ratio round-ended railway bridge piers are prone to flexural-shear failure in the transverse direction. A low-reinforcement ratio may lead to insufficient flexural reinforcement failure; (2) the primary crushing zone is located below 0.37 times the section height, with cracks primarily occurring below 0.5 times the pier height; (3) the reinforcement ratio and the shear-span ratio significantly influence seismic performance indicators. The stirrup ratio affects the occurrence and propagation modes of cracks; (4) the longitudinal reinforcement ratio, stirrup reinforcement ratio, and shear-span ratio positively influence the ductility of the piers. Small shear-span ratio bridge piers with low reinforcement do not exhibit lower ductility; in contrast, they may have higher ductility; and (5) a fiber-section bridge pier model optimized by a genetic algorithm effectively simulates hysteresis behavior. A three-dimensional solid model incorporating the bond-slip effect accurately simulates the bearing capacity and failure modes of bridge piers.