Anti-seismic Performance Study Of Precast Bridge Piers Connected With Grouting Corrugated Pipe

In recent years,precast structures had been widely used in bridge engineering in domestic construction,However,due to the lack of systematic research and understanding of the seismic performance,their application in the strong earthquake zone is limited.Ensuring the reliability of the connection between the pier and the cap or assembly segments of the precast bridge piers is the most critical issue to the study of its seismic performance.Grouting corrugated pipe connection is a simple and convenient way to connect the precast pier,but there is a lack of research on its seismic performance,especially its seismic performance under bidirectional load.Therefore,in this paper,four precast bridge piers connected with grouting corrugated pipe are designed and fabricated.Therefore,the bi-axial quasi-static test was used to study the hysteresis characteristics and failure mode under bidirectional reciprocating loads,and the feasibility of prestressed precast bridge piers connected with grouting corrugated pipe and the performance-based seismic analysis method were discussed.The main works are as follows:(1)Through the bi-axial quasi-static test of the precast bridge piers connected with grouting corrugated pipe,the hysteresis characteristics and failure mechanism of precast bridge piers are studied,and the influence of different axial compression ratio and slenderness ratio on the seismic performance of precast bridge piers is analyzed.(2)Based on OpenSees finite element software,bi-axial quasi-static test of precast bridge piers was simulated with fiber beam elements,and the effects of parameters such as the ratio of longitudinal reinforcement,reinforcement ratio of energy-dissipating steel were analyzed,and the seismic performance of the model of prestressed precast bridge piers connected with grouting corrugated pipe was analyzed.(3)The performance level of the precast bridge piers connected with grouting corrugated pipe is established,the quantitative indexes of the precast bridge piers are discussed,and using the method of reliability probability to analyzed the the vulnerability of precast bridge piers.The main conclusions are as follows:(1)The damage of precast bridge piers is mainly caused by the destruction of the joint,and the swing phenomenon is obvious.The corrugated pipe and the steel bar are connected reliably,and it has no relative displacement.Through comparative analysis of specimens,it is found that the larger the axial compression ratio,the more obvious the pinching phenomenon of the hysteresis curve of the specimen and the smaller the deformability;the larger of the slenderness ratio,the smaller the damage degree of the plastic hinge area,and the height of crack distribution of the pier body,and the smaller the ultimate load and the stiffness are,and the greater the deformation ability is.(2)The numerical simulation results are in good agreement with the experimental results.Using the parallel spring can well simulate the mechanical characteristics of the joints of precast bridge piers connected with grouting corrugated pipe.Adding prestress can improve the seismic performance of the precast bridge piers connected with grouting corrugated pipe to a certain extent,and proposes the formula for the residual deformation.(3)The Park-Ang index that considering the bidirectional load can reflect the actual damage state of the precast bridge piers better.The reliability analysis shows that under the same peak acceleration PGA,the exceeding probability each damage state of the transverse direction is lower than that of the longitudinal direction.Through the fragility curves,the probability of each damage state of the pier under a given earthquake can be determined.