Study On The Seismic Performance Of Precast Column With Intermediat Connection

Prefabricated construction technology is a hot spot in the construction industry..Connections are the key to prefabricated buildings.The performance of nodes controls the overall reliability of prefabricated building structures.Most of the existing prefabricated frame structure node connection methods are assembled by post-pouring beam and column nodes.There are more wet jobs on site,construction quality cannot be guaranteed,long construction period,and more on-site personnel.It cannot be applied in an environment where the construction conditions are bad and the personnel cannot work for a long time,and the advantages of the prefabricated building are not brought into play.This paper proposes a frame column-column node connection form,and the middle node is connected to the prefabricated column.The node connectors welded to the upper and lower longitudinal ribs are connected by bolts to form a whole.The finite element analysis method is used to evaluate the seismic performance of the precast column connected to the central node to verify that it can replace the cast-in-place column in engineering applications.The bearing capacity of the node area and the strength calculation method of the node are analyzed.The research contents are as follows:（1）Based on the domestic and foreign research results of the fabricated frame structure,the current situation of the fabricated frame column-column connection method is analyzed,a new type of fully dry intermediate connection prefabricated column is proposed,and the technical route of this article is given.This kind of prefabricated column sets the node connection point close to the inverted point,avoiding the complex beam-column node area,ensuring the reliability of the connection,better economy,and convenient on-site construction It solves the problem of limited application of existing wet concrete technology in areas with harsh construction conditions（Chapter 1）.（2）The joint form of the central node connecting the precast column is proposed,the size of the test piece is determined according to the actual engineering background,and the relevant mechanical properties are checked.The calculation results show that the design of the prefabricated column meets the design requirements（Chapter 2）.（3）The correctness of the finite element analysis method was verified through the simulation of existing dry-connected prefabricated columns,the results of four loading tests were compared with the the results of simulation,which verified the correct applicability of the finite element analysis method in the simulation of dry-connected prefabricated columns（Chapter 3）.（4）The finite element analysis method is used to analyze the seismic performance of the precast columns connected with the central nodes,and the seismic performance of the precast columns connected with the central nodes under the action of low-cycle repeated loads are simulated,such as the seismic performance,stress distribution,hysteresis curve,energy dissipation capacity,ductility,etc.Contrast with cast-in-situ columns.The results show that the hysteresis curve of the precast column connecting the central node is full,and the energy dissipation capacity before failure is similar to the energy dissipation capacity of the cast-insitu column.Based on the design parameters of axial compression ratio,rib thickness and steel plate hoop length,the seismic performance of the precast column connected with the central node was studied,and the influence of different parameters on the seismic performance of the precast column connected with the central node was summarized,and the central node connection was obtained.The scope of application of precast columns（Chapter 4）.（5）Based on the results of parametric analysis,the design of the precast columns connected to the central node was optimized,and the seismic performance of the optimized central node connected to the precast column was analyzed.The analysis results show that after optimization,the performance of the precast column connected to the central node has been significantly improved and has the same seismic performance as the cast-in-place column.According to the force condition of the nodes and related specifications,the calculation method and design points of the precast columns connected to the central node are proposed,which provides a design basis for engineering practice（Chapter 5）.