Research On The Seismic Performance Of RC Beam-Circular Tubed RC Column Interior Joints With Slab

Recently,the Tubed concrete columns have been widely applied in projects because of its high compressive strength,excellent deformability and scarcely buckling.At present,the researches mainly focuses on the static and seismic performance of the Tubed concrete columns,while the researches on the seismic behavior of joints are insufficient.Aiming at the RC Beam-Circular Tubed RC Column interior joints,two methods to strengthen joints were researched in this paper,containing semi-successive tubes joint and tube-rings joint.The seismic performance and shear load capacity of the two kinds of joints were studied,and the other main work and conclusions were as follows:(1).Three interior joints with slab and one interior joint without slab,which were strengthened by the method of semi-successive tubes and all had the same orthogonal beams,were classified according to the two parameters – the thickness of semi-successive tubes and axial compression ratio.By carrying out hysteretic experiment,the paper researched the failure modes,hysterics loops,skeleton curves,strength degradation,stiffness degradation,energy dissipation and ductility.Moreover,the influence of slab on the seismic performance of joint were analyzed.The result showed that the semisuccessive tubes joints have favorable seismic performance.(2).The ABAQUS finite element models of RC Beam-Circular Tubed RC Column joints were established.The failure modes and peak load capacity of the finite element method was in good agreement with the experimental results.Moreover,the influence of semi-successive tubes,concrete strength and straight beam on the failure modes and the shear load capacity of joints were analyzed.(3).The ABAQUS finite element models of joint strengthened by tube-rings were established,the diameter and spacing of tube-rings and the thickness of the joint tubes on the failure modes and the shear load capacity of the joints were researched.The results showed that,when achieving the same load capacity,the joint with tube-rings could use less steel compared to that joints with semi-successive tubes.(4).Referring to the experiment and finite element results,the shear mechanism of the two different kinds of joints were researched,and the shear capacity calculation formulas of two joints were put forward.The formulas were in good agreement with the results of experiment and finite element results.What's more,some corresponding construction measures were suggested.The innovation of the paper: 1)The experimental research on the seismic performance of RC beam-circular tubed RC column interior joints with slab were carried out;2)The ABAQUS finite element model of RC beam-circular tubed RC column interior joints strengthened by tube-rings were established;3)The shear capacity calculation formulas of two joints were put forward.The formulas were in good agreement with the results of experiment and finite element results;4)Some corresponding construction measures on the two joints were suggested.