Bi-axial Quasi-Static Experimental Study Of Precast Segmental Bridge Piers With Grouting Corrugated Pipe Connection

Because of the advantages of high construction efficiency,safety,environmental protection,cost reducing and so on,precast segmental bridge piers has been paid more and more attention.The seismic performance of the assembled bridge pier is the key point of the current study,and it is also the key problem that can be used in the high intensity seismic area.Connecting with grouting corrugated pipe connection is a simple connection method for precast pier,but the study on seismic performance is not sufficient,especially,the seismic performance and the corresponding analytical method study which considering the bilateral loads carried out less.Therefore,discussesing the hysteresis characteristics and failure modes of the precast segmental bridge piers connected with grouting corrugated pipe under the bi-axial reciprocating load in combination with the bi-axial quasi-static test and the nonlinear finite element analytical method,and the seismic performance of different design parameters were studied to provide the basis for seismic design and engineering application.The main works are listed as follows:(1)The bi-axial quasi-static test of precast segmental bridge piers with grouting corrugated pipe connection and the study of the hysteretic characteristics and failure mode,had been carried out.and had a comparative analysis of differences of seismic performance between segmental assembled pier and integral cast-in pier.(2)The finite element software OpenSees had been used to simulate the four piers by fiber unit.Had the impact analysis on axial compression ratio,longitudinal reinforcement ratio,energy dissipation reinforcement,prestressed reinforced bars,Initial prestress and other parameters.(3)The calculation formula of the ultimate bearing capacity of precast segmental bridge piers with grouting corrugated pipe connection under the action of bi-axial load had been deduced,and the experimental verification had been carried out.The main conclusions are listed as follows:(1)The damage process and failure mode of precast segmental bridge piers with grouting corrugated pipe connection are similar to those of the integral piers,they are both bending failure.But segmental assembled pier has a longitudinal buckling in the process of failure.Under the bi-axial horizontal loads,the segmental assembled specimen has a significant bi-axial loads coupling effect.Compared with the unidirectional loading specimen,the peak load of the specimen is not only greatly reduced,but also the ultimate displacement and yield displacement are obviously reduced and the specimen damage is more serious.(2)The parallel spring can simulate the mechanical properties of the joint of precast segmental bridge piers with grouting corrugated pipe connection well.The parameter impact analysis results show that increasing the axial compression ratio,adding energy-consuming reinforcement and adding prestressed reinforced bars can significantly improve its energy consumption and structural stiffness,making the seismic performance improved.(3)The bending moment calculation formula of the two directions under the bilateral bending action can be used to check the ultimate bearing capacity of the segment bridge pier.