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1

Shear force distribution law of inclined webs box girder under live load

Cui Yujun, Wu Longqing, Wang Weiqi, Cao Wei, Xue Xingwei

Archives of Civil Engineering

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2022

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Vol. 68, nr 2

593--610

EN

Inclined web box girders are widely used in urban areas because of their attractive appearance. However, there are few studies on the vehicle shear force distribution of this type of bridge. In this study, we established 62 three-dimensional finite element models in which the shear force of each web of the box girder can be extracted; furthermore, we investigated the shear force distribution law in webs of the box girder under live loads, including single-chamber and multichamber inclined web box girders. The main parameters studied include the number of vehicle lanes and chambers, slope of the inclined webs, and support conditions. The results reveal that an uneven distribution of web shear force exists in both the single-chamber box girder and multichamber girder under live loads, and the maximum value of the vehicle shear force distribution factor is greater than the average shear value shared by all webs. Therefore, the uneven distribution of shear force in the webs of the box girder cannot be ignored under eccentric vehicle loads. These values greatly exceed the safety factor of 1.15 that is used in conventional calculations.

2

Damage mechanism of conventional joints and proposal of a novel joint for hollow-core slab bridges

Cui Yujun, Xue Xingwei, Yao Hao, Hua Xudong, Huang Yuanming

Archives of Civil Engineering

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2022

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Vol. 68, nr 4

571--590

EN

The prefabricated hollow-core slab bridge is a common bridge. In prefabricated hollow-core slab bridges, joints play an important role in connecting prefabricated slabs and ensuring the integrity of the bridge. However, as the service time of the bridge increases, conventional joints have a large number of typical diseases that affect the safety and durability of bridges. In this study, a three-dimensional finite element model of the entire construction phase is established to investigate the development difference of shrinkage and creep between joints and hollow-core slabs. The effects of vehicle load and temperature gradient on joints were analysed, the failure mechanism of joints was explored, and a novel joint was proposed. The results of a nonlinear analysis showed that the novel joint can effectively improve the mechanical performance of joints and cracks can be effectively controlled. Moreover, the novel joint solves the problem in that the conventional novel joint cannot be vibrated effectively.

3

Analysis of static performance of cable-stayed arch cooperative bridge without back cable

Zheng Xilong, Cui Yujun

Archives of Civil Engineering

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2022

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Vol. 68, nr 2

531--548

EN

In this paper, the stiffness and internal force of the finite element model of a cable-stayed bridge, arch bridge and cooperative system bridge with the same span are analyzed, and the stress characteristics of cooperative system bridge compared with arch bridge and cable-stayed bridge are studied. In the stiffness analysis, the live load deflections of the arch bridge (maximum deflection - 6.07 mm) and the cooperative system bridge (maximum deflection - 6.00 mm) are similar, while the cable-stayed bridge (maximum deflection - 16.27 mm) has a larger deflection. In the internal force analysis, compared with the internal force of the main girder, it can be seen that the girder of the cooperative system bridge reduces the girder-column effect compared with the cable-stayed bridge. The main girder of the cooperative system bridge reserves more stress than the arch bridge. In the stress analysis of arch rib, the axial force and bending moment of arch rib under dead load of cooperative system bridges are greater than the cooperative system bridge. The maximum difference of axial force and bending moment between arch bridge and cooperative system bridge is 16.2% and 58.8%, but there is no obvious difference under live load. In the stress analysis of the cable tower, the advantages of the cooperative system bridge are more obvious under dead load and live load. In the comparative analysis between the cable and the derrick, the dead load and live load are mainly carried by the derrick, and the derrick bears 84% dead load and 97% live load. The research results can provide reference for the stress analysis of similar bridge structures.