关键词: 桥梁工程；装配式混凝土桥梁；损伤模型；刚度参数；接缝应力

Abstract: Under long-term loading and environmental actions, the joints of prefabricated concrete bridges are prone to occur damage, which alters the transverse load distribution characteristics and may cause potential safety hazards such as single-plate load bearing. To investigate the influence mechanism of joint damage on structural mechanical performance, a multi-parameter damage simulation method based on interface slip normal stress and shear stiffness parameters (Knn, Kss, Ktt) was proposed. A refined ABAQUS finite element model was established, and the joint stress mechanisms of hollow slab girders, small box girders, and T-girders under single hinge joint damage and multi-hinge joint damage conditions were analyzed from three dimensions such as longitudinal normal stress, transverse normal stress and vertical shear stress. The research results show that the longitudinal normal stress at the joint is symmetric about mid-span, and damage mainly affects the stress distribution near the mid-span and supports. The transverse normal stress fluctuates near mid-span, and the more severe the damage, the larger the stress deviations are. The vertical shear stress exhibits an antisymmetric distribution, and the variation trend of stress curves after damage shows significant differences among different girder types. The overall stress distribution trend at the joint does not change markedly before and after damage. For hollow slab girders, the controlling order is transverse normal stress, vertical shear stress, and longitudinal normal stress; for small box girders and T-girders, the controlling order is vertical shear stress, transverse normal stress and longitudinal normal stress.

Key words: bridge engineering; prefabricated concrete bridges; damage model; stiffness parameters; seam stress