Study On Seismic Performance Of Prefabricated Bridge Piers With End-reinforced Socket Connection

The total number of bridges in my country ranks first in the world.However,most of the bridges use cast-in-place construction.Factors such as large construction dust,serious impact on traffic,and long construction period have severely restricted the development of urban bridges.Prefabricated assembly technology is an effective method to solve this problem.The connection methods for the substructure of the bridge mainly include grouting sleeve connection,prestressed tendon connection,socket connection and so on.The socket connection is convenient for construction and requires low construction accuracy,but the seismic performance is lower than that of the cast-in-place connection.Therefore,with the help of numerical simulation and theoretical analysis,this thesis proposed a socket connection method for the reinforced pier and the cap foundation of the column end.The article also compares the performance difference between the column end reinforced socket connection and the standard socket connection,and the cast-in-place connection.Finally,a finite element model was established to analyze the influences of aspect ratio,width ratio,pier section size and other factors on the seismic performance of the piers with end-reinforced socket connection.The impact of the new prefabricated bridge pier on the seismic performance,and the size of the strengthened end of each section is given.The main work content and conclusions are as follows,(1)The bridge pier model was established using finite element software ABAQUS,and the related details of model simulation were explained,such as the selection of material constitutive structure,element type,contact attribute setting,etc.A finite element model corresponding to the quasi-static test is established to verify the rationality of the modeling of prefabricated bridge piers with socket connection.The results show that the simulated skeleton curve and hysteresis curve are in good agreement with the experimental values.The material constitutive,contact properties,and mesh divisions selected in this thesis are all set reasonably,which can accurately reflect the stress of the prefabricated bridge pier under quasi-static load.(2)In order to obtain the best insertion depth of the prefabricated bridge piers with socket connection,this thesis designed piers with different aspect ratios for the piers of different cross-sections.By comparing the skeleton curves of different cross-sections at different aspect ratios,it can be obtained: for the standard socket connection without shear key,when the aspect ratio is about 1.2,the bearing capacity of the standard socket pier is close to the performance of the cast-in-place pier.(3)This thesis proposed a prefabricated bridge pier with end-reinforced socket connection.The kind of piers with cross-sections of 350 mm,400mm,and 450 mm are simulated respectively,and their width ratios of the connections are studied while the socket depth is constant.The influence of width ratio on the seismic performance of bridge piers with end-reinforced socket connection is analyzed.Studies have shown that as the width ratio increases,the seismic performance of the column-end reinforced socket connection also gradually improves.For column-end reinforced socket connection piers with different cross-sections,this study gives the recommended width ratios of each cross-section.For pier cross-sections of 350 mm,400mm,and 450 mm,the recommended width ratios are 0.25,0.35,and 0.45,respectively.By fitting the relationship between the width ratio and the section width of each section,it is concluded that they satisfy the functional relationship of y=0.002x-0.45.