Fatigue performance analysis of long cantilever cap beam in segmental precast concrete bridge pier

Abstract

As bridge construction trends toward industrialized, large‐span solutions, segmental precast technology has gained prominence for its efficiency, quality control, and environmental benefits. The long cantilever cap beam, a vital connection between superstructure and substructure, plays a key role in transferring loads to bridge piers, especially in urban areas with limited space. Despite the increasing use of segmental precast methods, limited research exists on the fatigue performance of such cap beams under prolonged traffic and environmental loading. This study examines the fatigue behavior of a segmental precast long cantilever cap beam through a real engineering case. Finite element models were developed in ABAQUS finite element analysis software (ABAQUS) and Finite Element (FE)‐Safe to simulate static and fatigue conditions, integrating actual traffic data and material degradation from corrosion. Fatigue loads were derived using Miner's linear damage theory and equivalent damage principles. The results indicate that the cantilever end develops the largest deflection during service life, primarily owing to fatigue accumulation and the early onset of material deterioration. Prestressed tendons at joints consistently experience higher tensile stress than those in segments due to earlier corrosion onset. Nonetheless, concrete remains in compression and reinforcement stress stays within design limits, confirming the beam's structural reliability under combined fatigue and durability effects. These findings provide a useful basis for the design optimization, durability assessment, and maintenance planning of segmental precast cap beams in space‐constrained urban bridge projects.