Finite Element Analysis of Highly Skewed Bridge Superstructures under Various Loading Conditions: A Systematic Review

Abstract

Objective: This study examines the behaviour of highly skewed bridge superstructures under varying loading conditions, with a focus on how finite element analysis (FEA) can improve understanding of, and support improvements in, their structural performance. Particular attention is given to load distribution, torsional behaviour, stress concentration, and the influence of skew angle on overall bridge response. Study Design: The study adopts a systematic review approach by synthesising existing research on highly skewed bridge systems from the structural engineering and computational mechanics literature. The review focuses on how recent studies have used finite element methods to investigate the complex behaviour of skewed bridge superstructures and to evaluate possible optimisation strategies. Methodology: Relevant studies were identified through searches of ScienceDirect, SpringerLink, ASCE Library, Scopus, Web of Science, and Taylor & Francis Online. The review considered peer-reviewed studies published between 2019 and 2026 that examined skewed bridge behaviour using finite element modelling under dead load, live load, thermal loading, and dynamic or seismic effects. In total, 47 studies met the inclusion criteria and were grouped into major themes, including skew-angle effects, finite element modelling techniques, load-response behaviour, diaphragm and cross-frame configuration, and optimisation approaches for improving structural efficiency. The final database search was completed on 6 May 2026. Results: The reviewed studies consistently show that increasing skew angle changes the way forces are transferred through bridge superstructures, leading to uneven girder loading, larger torsional effects, rotational behaviour, localised deck stresses, and differential deflections. Finite element analysis was found to provide a more realistic representation of these behaviours than simplified analytical methods, especially in bridges with large skew angles. The literature also shows that improvements in diaphragm arrangement, cross-frame configuration, girder spacing, and bearing layout can help reduce stress concentration and improve overall structural performance. At the same time, several studies reported noticeable differences between AASHTO LRFD predictions and detailed finite element results for highly skewed systems. Conclusions: Finite element analysis remains one of the most effective tools for studying and optimising the behaviour of highly skewed bridge superstructures. The reviewed research shows that detailed three-dimensional modelling is essential for capturing the complex response associated with large skew angles and for developing more reliable optimisation strategies. Although recent studies demonstrate significant progress in improving bridge performance and analysis accuracy, challenges related to model calibration, computational cost, and realistic boundary-condition representation still require further investigation.