Study On Seismic Behavior Of Prefabricated Piles And Columns Foundation

With the rapid development of urbanization in China,there are more and more urban bridges to solve the problem of traffic congestion in cities.However,the construction of these bridges has a series of problems such as long construction period and large environmental impact.The prefabricated assembly structure has significant features and advantages,and the industry is actively promoting it.As the weak and key part of the prefabricated assembled pier,the seismic performance of the node is the focus of attention.This paper studies the seismic performance of prefabricated pilepillar foundations,which has important theoretical significance and engineering practice background.Based on the actual engineering background,three experimental model specimens in this paper(1 cast-in-place girder specimen,1 precast mast cap beam slot joint test piece,1 prefabricated pipe pile and prefabricated pipe column flange)were designed.The disk was connected to the test piece),and a full-scale model quasi-static experiment was performed.Through the phenomenon and failure mechanism of the experiment to analyze the reliability and seismic performance of the slot-and-slab beam slot connection and pile-flange connection.The research results can provide reference and basis for the prefabricated assembly engineering application design.The main research contents of this paper are as follows:(1)A comprehensive summary of the classification,application and research status of prefabricated assembly technology.The prefabricated slot-type cap beam and pier column connection joints were compared by experimental research(prefabricated assembly and cast-in-place),pointed out the damage development process of the slotand-slot beam slot connection method,and analyzed the failure mechanism.The conclusion that this connection method is safe and reliable is obtained.(2)The reliability of the flange connection method of prefabricated pipe columns and PRC pipe piles with different diameters was tested,and the damage process was revealed,and verified the reliability of flange connection.(3)In order to further study the seismic performance of various piers with different pier heights,Numerical analysis of more operating conditions was carried out based on ABAQUS finite element software.Numerical analysis is based on test results.and the simulation parameters and process were corrected.Then the model was extended,and the seismic performance analysis results of the piers under other pier height conditions in engineering practice was obtained,and the reliability of slot connection was widely demonstrated.(4)In this paper,the transverse bridge-to-structural cover beam of the project was checked as a capacity protection component,and static elastoplasticity pushover analysis was carried out.The analysis results show that the bearing beam does not yield when the pier was damaged,and it is still in the elastic stage.The original design meets the requirement of the cover beam as the capacity protection component.