In this paper, the solitary wave forces on coastal bridge superstructures with box girders are discussed numerically. Although there are some empirical equations for wave forces on typical bridge superstructures, no relation has yet been proposed for predicting the tsunami-induced forces on box girder superstructures due to the lack of knowledge of wave forces on these kinds of superstructures. In this study, first, a solitary wave model was utilized to represent the tsunami. Then, the Reynolds-averaged Navier-Stokes equations combined with the shear stress transport (SST) k-ω turbulence model were utilized for the wave simulations. Additionally, the horizontal and vertical forces on the bridge superstructures were simulated, taking into account four water depths and five wave heights for each bridge elevation. The effectiveness of the numerical model was proven by a comparison with the experimental measurements. The numerical results showed that the difference in wave forces acting on T-type girders and box girders was significant. Finally, an improved empirical equation was proposed for estimating the tsunami-induced forces on box girder bridges.

Structural health monitoring (SHM) is a critical technology for ensuring infrastructure safety, extending their service life, and reducing their maintenance costs. With the rapid development of digital twin (DT) technology, an increasing number of studies have implemented DT in SHM systems. This study provides a detailed analysis of the role of DT in SHM through a comprehensive literature review, specifically examining its applications in damage detection, dynamic response monitoring, and maintenance management. The paper first reviews advances in DT applications across various fields, then systematically discusses how DT enhances monitoring accuracy, enables real-time performance, and supports predictive maintenance strategies in SHM. Finally, technical challenges and future research directions for DT implementation in SHM are explored. The findings highlight DT’s significant potential to improve both the efficiency and the accuracy of structural monitoring systems, while proposing innovative solutions for intelligent infrastructure management.

In this paper, a two-dimensional (2D) model for wave-current girder interactions is established to investigate the effect of wave-current forces on box girder bridges. Reynolds averaged Navier-Stokes (RANS) equations combined with the k-ε turbulence model are applied for wave-current simulations, and the volume of fluid (VOF) method is used to trace the free water surface. Compared with previous studies, this paper (1) investigates the influence of the current velocity on the wave force on a coastal bridge box girder under extreme conditions, (2) analyzes the wave forces on the vulnerable positions of a box girder bridge, and (3) proposes simple and accurate equations for predicting the wave-current forces on a box girder bridge. The numerical model presented in this paper is first validated by comparing data obtained from the laboratory experiments. Next, parametric studies are conducted to examine the influence of the current velocity on wave-current forces under different effect factors, including extreme wave characteristics, relative water depths, and submerged depths. The influence of the geometrical shape of the box girder on the wave forces is considered. Finally, based on the numerical results, empirical equations predicting the wave-current forces on a box girder bridge under various effect factors are proposed as a method of protecting coastal bridges from damage under extreme wave loadings.