Research On The Mechanical Performance And The Influence Of Suspender Damage Of Concrete-Filled Steel Tube Arch Bridge

Based on the engineering background of the Shahe Bridge,this paper uses the finite element software Midas/Civil to establish a full-bridge finite element model of the concrete-filled steel tube arch bridge.And the influence of suspension rod damage on static and dynamic performance of concrete-filled steel tube arch bridge.The main conclusions obtained in this thesis are shown below:(1)The finite element software Midas/Civil was used to simulate the bridge,and the finite element calculation model of the bridge was given.During the construction phase,with the tension of the tie rods,the displacement of the longitudinal beams and the arch ribs will decrease,but the displacement of the arch ribs will always increase.After the arch rib bracket is removed,the steel pipe and concrete of the arch rib bear compressive stress;while the longitudinal beam has basically been subjected to tensile stress,and after the tie rod tension is completed,the tensile stress of the longitudinal beam will also be reduced.(2)With the passage of time,the shrinkage and creep of the concrete increase the pressure on the steel pipe of the arch rib,and the pressure on the concrete inside the arch rib decreases;the bending moment of the concrete and the steel pipe inside the arch rib have different cross-section changes,but The change is minor.(3)The concrete creep causes the compressive stress of the concrete in the arch rib to continue to decrease,and the compressive stress of the steel pipe continues to increase;the stress change in the initial stage of shrinkage and creep is relatively large,and the change will be slower in the later stage.(4)According to the robustness index of the importance factor of the component and the structural sensitivity,the influence on the structure after the damage of the corresponding suspension rod at the position of the arch foot,1/8 span,1/4 span and the vault section is obtained.relatively bigger.After the boom is damaged,the influence on its own stress change is the most obvious.The closer the boom is to the arch,the more sensitive it is to damage.(5)The fracture of the suspension rod at the support of the bridge deck system has the most obvious impact on the stiffness of the bridge deck system,and the stiffness of the bridge deck system is significantly reduced.The other suspenders are located at the continuous support of the bridge deck system,so their fracture has little effect on the rigidity of the bridge deck system.At the broken boom,the curvature modal difference of the tie beam will change suddenly,and the position of the broken boom can be judged by the curvature modal difference.