Study On Mechanical Behavior Of Joints Of Prefabricated Segmental Bridge Piers Under Quasi-static Force

As the weak link of precast segmental bridge pier,the strength and stability of precast segmental bridge pier are directly affected by the joint strength.Because of the unpredictability of earthquake disaster,it is very important to study the mechanical behavior of precast segmental bridge pier joints considering the interaction of shaft-bend-shear.Therefore,the mechanical behavior of the joints of precast segmental bridge piers is studied as follows:(1)Based on the Literature Review,the research status and three-level damage assessment methods of precast segmental bridge piers subjected to shear are summarized.(2)The finite element model of precast segmental bridge pier is established considering the contact nonlinearity of joints,and the direct shear test and pseudo-static test of precast segmental bridge piers are simulated,the simulation results are in good agreement with the experimental results,which verifies the reliability of the modeling method.(3)First,the finite element model based on material damage for prefabricated segmented pier piers through Open Sees,and then evaluated the damage of the prefabricated segmented pier pier bottom joints considering the axial force-bending moment-shear force interaction from the material level.Through the analysis,the damage index of the bottom section of UBPC-2 pier can be more accurately determined when considering the interaction of axial force-bending moment-shear force;through the damage analysis based on the stiffness degrad ation of UBPC-2 specimen when considering the interaction of axial force-bending moment-shear force,it is found that the whole UBPC-2 specimen is mainly bending failure.Finally,the damage of the joint at the bottom of the pier is evaluated considering the axial bending shear interaction,and the suggestions to improve the seismic performance of the prefabricated segmental pier are put forward.(4)In this paper,the influence factors of the joint deformation at the bottom of precast segmental bridge pier under monotonic horizontal load are analyzed by using the method of orthogonal test design.To investigate the influence of main influencing factors on the opening displacement,shear dislocation and joint damage at the bottom of precast segmental bridge pier.Some suggestions are put forward to reduce the deformation of the joints at the bottom of precast segmental bridge piers.