Dynamic Response Analysis And Anti-collision Performance Study Of Prefabricated Bridge Piers Under Vehicle Impac

Prefabricated piers have the advantages of fast construction speed,high production quality,and low impact on existing traffic and surrounding environment,and are widely used in urban bridge construction.During operation,bridge piers are at risk of vehicle collisions,and their anti-collision performance is critical to the safety of bridge structures.At present,the research on the stress behavior of bridge piers under vehicle collision is mainly cast-in-place concrete piers,and the anti-collision performance of prefabricated piers is not sufficient.In this paper,finite element numerical simulation is used to study the dynamic response and collision avoidance performance of prefabricated piers under vehicle impact.The main contents include the following:(1)By establishing the finite element model of vehicle-axle collision,ABAQUS was used to numerically simulate the collision process of prefabricated assembled piers,and the structural deformation,material damage and prestress of prefabricated piers under vehicle collision were analyzed.The differences in the anti-collision performance of prefabricated piers and cast-inplace concrete piers and the influence of different parameters on the dynamic response of prefabricated piers were explored,and the effects of different vehicle speed,mortise and tenon size,initial prestress and other factors on the anti-collision performance of prefabricated piers were compared.(2)Add a certain volume fraction of steel-polypropylene hybrid fiber to the concrete at the bottom of the pier to make up for the defects of ordinary concrete properties.Considering the influence of fiber on the constitutive structure of concrete material,the dynamic response of prefabricated piers during the collision process was numerically simulated by using the modified plastic damage model,and the influence of fiber concrete on the anti-collision performance of prefabricated piers was analyzed.(3)According to the tenon and tenon connection form between concrete segments,the influence of the length,width and other parameters of the mortise and tenon on the collision resistance performance of the prefabricated pier was analyzed,and the failure form and deformation characteristics of concrete under different tenon and tenon sizes were obtained,and a reasonable tenon and tenon size range was given.(4)According to different concrete segment connection methods,the collision response of the assembled pier connected by steel pipe and flange-bolt device is analyzed,and the dynamic response of the mortise and tenon pier is compared with the dynamic response of the mortise and tenon pier,the bending and shear resistance performance of different connection methods of the pier segment is analyzed,the influence of different connection methods on the dynamic response of the assembled pier is studied,and the appropriate connection method is obtained.