Curved composite girder bridges with corrugated steel webs (CSWs) have already been constructed around the world. However, limited work has been done on their shear behavior. In this paper, the corrugated steel web (CSW) in horizontally curved girders (HCGs) is treated as an orthotropic cylindrical shallow shell, and the analytical formula for the elastic global shear buckling stress is deduced by the Galerkin method. Calculation tables for the global shear buckling coefficient for a four-edge simple support, for a four-edge fixed support, and for the two edges constrained by flanges fixed and the other two edges simply supported are given. Then, a parametric study based on a linear buckling analysis is performed to analyze the effect of the curvature radius and girder span on the shear buckling stress. Analytical and numerical results show that the difference of shear buckling stress of CSWs between curved girders and straight girders is small, so the shear design formulas for straight girders can be applied for curved girders. Finally, a series of tests were performed on three curved box girders with CSWs. Similar to CSWs in straight girders, the shear strain distributions of CSWs in HCGs are almost uniform along the direction of the web height and the principal strain direction angles are close to 45°. For the three specimens, CSWs carry about 76% of the shear force. In the destructive test, shear buckling after yielding occurred in all specimens which is in good agreement with the theoretical prediction, which means that the analytical formulas provide good predictions for the shear buckling stress of CSWs in HCGs and can be recommended for design purposes.

Curved composite box girder bridges with corrugated steel webs (CSWs) have already been constructed around the world. However, limited work has been done on the comparisons of mechanical properties between curved box girders (CBGs) with CSWs and CBGs with traditional concrete webs. This can be attributed to the difficulty separating flexure, torsion, and distortion using experimental or finite element analysis methods. In this paper, first, a practical method that can solve deflections, torsional angles, distortional angles, stresses, and internal forces of simply supported and continuous CBGs with intermediate diaphragms is introduced. Then, a parametric analysis is conducted to study the difference in mechanical properties of CBGs with CSWs and CBGs with concrete webs. The results show that: (1) Compared with traditional concrete box girders, the torsional and distortional resistances of box girders with CSWs are significantly reduced. Under external loading, all deflections, torsional angles, distortional angles, flexural normal stresses, restrained torsional and distortional warping normal stresses are generally larger. (2) For the example presented in this paper, the torsional warping normal stresses can reach 30% of the flexural normal stresses, and the distortional warping normal stresses can reach 80% of the flexural normal stresses. For this reason, they cannot be neglected in the design. (3) By increasing the number of intermediate diaphragms, drawbacks of using CSWs due to the increase in distortional angles and distortional warping normal stresses can be mitigated, closing the gap between the 2 different web types. In this regard, it is suggested that at least 1 diaphragm should be installed at midspan and if the diaphragms are arranged by equal spacing, their number is suggested to be odd.

The welded joints in steel bridges have a complicated structure, and their fatigue life is mainly determined by the real stress under the coupling effect of vehicle load stress, as well as weld-induced residual stress and its relaxation. Traditional fatigue analysis methods are inadequate for effectively accounting for weld-induced residual stress and its relaxation, resulting in a significant discrepancy between the predicted fatigue life and the actual fatigue cracking time. A fatigue damage assessment model of welded joints was developed in this study, considering weld-induced residual stress and its relaxation under vehicle load stress. A multi-scale finite element model (FEM) for vehicle-induced coupled analysis was established to investigate the weld-induced initial residual stress and its relaxation effect associated with cyclic bend fatigue due to vehicles. The fatigue damage assessment, considering the welding residual stress and its relaxation, was performed based on the S–N curve model from metal fatigue theory and Miner’s linear damage theory. Based on this, the impact of variations in traffic load on fatigue life was forecasted. The results show that (1) the state of tension or compression in vehicle load stress notably impacts the residual stress relaxation effect observed in welded joints, of which the relaxation magnitude of the von Mises stress amounts to 81.2% of the average vehicle load stress value under tensile stress working conditions; (2) the predicted life of deck-to-rib welded joints is 28.26 years, based on traffic data from Jiangyin Bridge, which is closer to the monitored fatigue cracking life when compared with the Eurocode 3 and AASHTO LRFD standards; and (3) when vehicle weight and traffic volume increase by 30%, the fatigue life significantly drops to just 9.25 and 12.13 years, receptively.

This study conducted punching shear tests on steel grid–ultra-high-performance concrete (UHPC) composite bridge decks and performed finite element analysis (FEA) to evaluate their punching shear performance. Initially, a comparative analysis is conducted between the test results and FEA results. The findings indicate that, due to the presence of T-shape steel in this new type of bridge decks, variations in the spacing between adjacent T-shape steel members can lead to two distinct punching shear failure modes: conventional failure mode and unconventional failure mode. Under identical conditions and test specimen parameters, the punching shear capacity associated with the unconventional failure mode is approximately 35% higher than that of the conventional failure mode. Subsequently, a parametric analysis is performed using the FEA method, and the results indicate that, for the composite bridge deck experiencing conventional failure mode, the punching shear capacity decreases approximately linearly with increasing UHPC plate width, whereas it increases approximately linearly with increasing UHPC plate thickness. The type of T-shape steel exhibits negligible influence on the punching shear capacity of the steel grid–UHPC composite bridge deck. Finally, based on the formula for calculating the punching shear capacity of conventional plates in Chinese standards, this paper introduces a correction coefficient that accounts for the width-to-thickness ratio of UHPC plate and proposes an improved calculation method applicable for determining the punching shear capacity of steel grid–UHPC composite bridge decks under conventional punching shear failure mode condition.

Through static bending tests on two full-scale specimens of a new steel grating–UHPC (ultra-high-performance concrete) composite bridge deck, the load–displacement curves, crack propagation, strain distribution, and failure characteristics were analyzed. According to the experimental results, a numerical model was established using ABAQUS software 2021, in which two contact methods were employed to simulate the interfacial connection between UHPC and steel. The results indicate that the surface-to-surface contact method provides better agreement with the experimental data. Subsequently, conducted parameter studies using this model to investigate the impact of key geometric parameters, including section height, flange width, flange thickness, steel bottom plate thickness, and steel web plate thickness, on the flexural performance of the structure. The results demonstrated that the section height and the steel bottom plate thickness had a significant effect on the load-bearing capacity and overall stiffness of the component, while the influence of other parameters was comparatively minor. Finally, based on both experimental and numerical results, a formula for calculating the flexural bearing capacity of steel grating–UHPC composite bridge slabs was proposed, providing a reference for the structural design and promotion of the new composite bridge deck.