Research On Seismic Performance And Design Method Of Prefabricated Double Column Pier

Bridge assembly construction can not only greatly improve construction efficiency of bridge construction,but also in a better guarantee of bridge construction quality,which has become a common construction method in bridge construction.However,in the research on prefabricated piers,there are few studies on double-column piers,and the research direction is mostly the connection between piers and bearing pier caps,and there is a lack of research results on the connection method between pier sections.Based on this,this paper proposes a doublecolumn pier assembly method using ultra-high performance concrete as grouting and wet joint material.This connection method introduces the new material UHPC,which is popularity today,into the prefabricated assembled piers,forming a prefabricated assembling method using grouted corrugated pipes connection between piers and cap beam bearing,and using cast-inplace wet joint connection between pier sections.The quasi-static test research is conducted on the double-column piers under this connection method to investigate the reliability of this connection method and the seismic performance of this pier system,and further refine the detailed structure of this connection method on this basis.The main research work of this paper is as follows.(1)By reviewing the research on prefabricated assembled pier structure at home and abroad,the research results and conclusions of this pier system are systematically understood and sorted out today.Based on the current research results,the prefabricated assembled pier form with UHPC hybrid connection is proposed,and the research ideas,specific research objectives and main research contents of this paper are summarized to provide effective ideas to solve some shortcomings of the present research on prefabricated assembled piers.(2)On the basis of ensuring the reliability of the connection parts of the splicing method,further detailed studies were conducted on the joint structure,including the longitudinal reinforcement arrangement of the bridge pier,the shear design of the joint between the bearing deck cover beam and the pier,the connection length of the corrugated pipe and the height of the wet joint of the segmental pier.In order to improve the construction economy and construction convenience of the connection method.(3)The quasi-static test of the double-column pier with UHPC hybrid connection were carried out,and the construction form and assembly method of the double-column pier specimen were determined.The test data of hysteretic energy dissipation,plastic hinge formation,stiffness degradation,joint surface connection performance and reinforcement strain of the bridge pier specimen under cyclic loading were analyzed to investigate the reliability of the connection method and the seismic performance of the double-column pier with this connection method.(4)Numerical simulation analysis of the double-column pier with UHPC hybrid connection is carried out based on ABAQUS.By reasonably defining the material properties of the model and the contact mode of each splice,the numerical analysis model of the doublecolumn pier under this connection method is established.The analysis of the model operation shows that the model calculation results fit well with the quasi-static test results.This provides a reference for the future application of this connection method in high intensity seismic zones by means of numerical simulation of the whole bridge under the action of earthquake.(5)The seismic design method of the UHPC hybrid connection pier system is investigated.Based on the results of the quasi-static test and numerical analysis of the two-column pier specimens,the seismic design method based on the displacement ductility coefficient is combined with the seismic design method,and the correspondence between different ductility coefficients and the damage at all levels of the bridge pier is proposed.On this basis,some seismic design measures and construction suggestions are proposed for the bridge pier system with this connection method,which will provide reference for the future design of the bridge pier system with UHPC hybrid connection.