Research On The Structure And Static Structural Behavior Of Steel-concrete Composite Joint Of Special-shaped Pylon

Steel-concrete composite pylon fully utilizes the respective advantages of steel and concrete materials,which has the characteristics of lightweight,high rigidity and large loadbearing capacity.The back-plate-type steel-concrete composite joint with cells is often used as a connection between the two materials.Pylon with special-shaped curve layout has significant spatial force characteristics and extremely complicated force feature.And this type of steel-concrete composite joint will bear larger shear forces,which is different from the normal.Location,stiffness matching relationship,stress state and deformation,transfer mechanism of back-plate-type steel-concrete composite joint with cells of pylon is studied,based on the No.2 Bridge located at BEDA of Zhangjiakou City.(1)According to the design information of bridge,FEM was established with MIDAS /Civil software.Mechanical reaction and deformation of the bridge is analyzed under constant load,vehicle load,temperature action.It shows that deformation of the bridge is small,negative moment occurs at pylon-beam rigid zone and auxiliary pier,moment of main beam is relatively minor,and the maximum moment of the bridge appears at the junction of the upper and lower pylon.(2)Following the previous principle of setting the steel-concrete composite joint,the position change of the steel-concrete composite joint of the pylon on the mechanical properties is studied.The reasonable steel-concrete composite joint position is obtained.Stiffness matching of steel-concrete composite joint is analyzed,stiffness transition is smooth and the structure design is reasonable.(3)To investigate force distribution of steel-concrete composite joint under the most adverse load condition,FEM of the back-plate-type steel-concrete composite joint with cells is established by ANSYS.(4)Based on FEM results,axial force transfer index is proposed.The force transfer mechanism is obtained by partial FEM,the result of stiffness matching study is compareed.Furthermore,the effects of design parameters including the width of steel lattice chamber,the height of bearing-plate and the thickness of bearing-plate to axial force transfer mechanism of steel-concrete composite joint are analyzed.