Study And Application On Connection Performance Of Prefabricated Bridge Precast Hollow Bridge Pier And Pile Cap

As a traditional construction method,cast-in-place concrete is widely used in the pier construction of bridge construction in our country.However,due to the disadvantages of large site wet work,long construction period and great influence on the environment,such construction method no longer meets the requirements of building industrialization and green construction.In order to deal with the defects of cast-in-place concrete construction,the prefabricated bridge with the technologies of factory production and site assembly has obvious superiorities,such as higher mechanized construction level,quicker construction speed and beneficial to environmental protection,has become the development trend of bridge construction.Prefabricated bridge pier serves as the main load-bearing component of the bridge structure and its connection with the pile cap is the weakest part in the prefabricated bridge structure,which is the most vulnerable to be damaged in the earthquake.The common connections between the precast pier column and the pile cap can be divided into cast-in-place and spigot type.Both of these two connections have disadvantages including difficulty in positioning the precast pier,heavy site welding workload,complex concrete pouring process and poor shear performance of joints between the pier column and the pile cap In this paper,combining with the approach bridge project of Huai River Bridge in Ji-Qi highway,the stress and deformation properties of the two connections are simulated by nonlinear finite element analysis software ABAQUS,based on the in situ loading test carried out on two connections of circular reinforced concrete precast hollow bridge pier with pile cap.A reasonable construction technological process is proposed to ensure the connection quality between the bottom of the pier and pile cap.Main research contents include:(1)Through the in situ loading test,the failure process and failure patterns of the pier and the pile cap joints are obtained,and the load-displacement carves and load-stress carves of two specimens are analyzed,also the stress performance and deformation capacity of two connections of steel plate shear studs and trapezoidal shear rings are analyzed and compared.The results shows that two specimens failure patterns are basically the same,the failure patterns of the two specimens are both flexural failure with the precast pier concrete cracking in the tensile zone above the top of the pouring cup;the connection performance of the trapezoidal shear ring connection is more stable.(2)The appropriate stress-strain constitutive relation of specimen materials are selected and the finite element analysis models of two specimens are established by using software ABAQUS.The reasonable boundary conditions and the section contact are set up for the proper meshing,the stress process of the specimens under the horizontal and vertical loading are simulated and the structural capacity curves are drawn.The simulation results are compared with the experimental results,and the results are in good agreement with each other,which verifies the rationality of the finite element simulation of the joint of the prefabricated hollow piers and the pile cap.(3)Based on the experimental research and theoretical analysis,a reasonable construction technological process and systematic construction method are presented and successfully applied in practical project,through the comparative analysis and objective evaluation of the construction methods of two connections.On this basis,2 national utility model patents have been authorized and 1 provincial-level construction method has been obtained.The research of this paper provides a theoretical basis and construction method for further improving the application of prefabricated bridge.It is of great significance to promote the application of prefabricated concrete bridge in engineering practice and promote the development of building industrialization.