Assessment of the behavior of railway bridge piers under seismic load using pushover analysis

The construction of railroad bridges aims to redirect traffic and mitigate congestion in high-density areas. This study involves 3D finite element modeling of a double-track steel frame bridge using CSi Bridge software based on engineering design data. Seismic analysis results for the six pillars show maximum displacements of 35.3208 mm in the longitudinal direction (X-axis) and 29.7877 mm in the transverse direction (Y-axis). The structural integrity is confirmed by a demand-to-capacity ratio of 0.268, significantly below the safety threshold of 1.0. Load analysis indicates that the long-span condition with two passing trains generates the highest stress, reaching a maximum moment of 2.00 x 104 kNm and a shear force of 8.64 x 103 kN. These values exceed those recorded for single-train or short-span scenarios. Overall, the analysis demonstrates that the bridge design is structurally sound and safely accommodates both seismic forces and operational train loads.