Novel macroscopic mechanical model for rapid and refined analysis of link slab bridges

Abstract Debonded link slabs are commonly adopted to replace the expansion joints of existing simply supported bridges, thereby protecting the girders and piers underneath them from exposure to water and deleterious agents. The primary challenges for the accurate simulation of link slab bridges are the modeling of slab-girder interaction as well as cracking and plastic behavior in both girders and link slabs. However, these nonlinear effects are not fully captured by the current analysis methods, leading to inconsistent research findings. In this study, a refined finite element model (FEM) was established in ABAQUS to simulate the behavior of link slab bridges, and its accuracy was validated by comparison with existing test data. The simulation results indicated that: (1) the inconsistent findings in previous studies are partly attributed to the neglect of cracking and plastic behavior in girders, and (2) debonded link slabs are separated from girders under vertical loads. A novel macroscopic mechanical model was developed based on a "two-point contact" deformation pattern to simplify the complex interaction between the link slabs and girders. Moreover, both the tensile force and bending moment in the link slab were incorporated into the macroscopic model to improve simulation accuracy. The model formulations were derived based on different support conditions. This macroscopic model can be naturally integrated with existing general numerical approaches, such as the finite element method, discrete element method, and applied element method, allowing cracking and plastic behavior in girders to be incorporated into the numerical formulation. The accuracy of the developed macroscopic model was validated by comparison with the simulation results of the refined FEM. Finally, an influence analysis was performed using a macroscopic model to investigate the behavior of the link slab bridges.