Seismic Performance And Isolation Technology Analysis On CFST Tied Arch Bridges

The development of concrete-filled steel tube tied arch bridge is limited by its structural features which are the internal statically indeterminate and much many components,the theoretical research on concrete-filled steel tube tied arch bridge seriously lags behind the actual construction speed and the theoretical system research is not perfect,especially on the seismic response and mitigation measures of concrete-filled steel tube tied arch bridge,and the design method and the application effect of the concrete-filled steel tube tied arch bridge have not been well studied,the dynamic analysis of the concrete-filled steel tube tied arch bridge is not considered in the design process,which limit the theoretical development level of the concretefilled steel tube tied arch bridge.Therefore,based on the analysis of related literatures and data both at home and abroad,this paper intends to clarify the influencing factors in the seismic response analysis of the concrete-filled steel tube tied arch bridge and the design method of reducing the seismic isolation bearing firstly,and to analyze the seismic response of the concrete-filled steel tube tied arch bridge The research system of reducing shock isolation measures forms some supplements and suggestions.The main research contents are as follows:(1)Based on the analysis of the existing concrete-filled steel tube tied arch bridge at home and abroad,inducting and summarizing the existing research on the technical standards of concrete-filled steel tube tied arch bridge,the static characteristics,stability,dynamic characteristics and seismic response of structure,And analyze and compare the characteristics and applicability of the seismic response analysis methods of various structures to determine the analytical methods and contents of this paper;(2)Through the finite element modeling with SAP2000 software and based on the exist engineering example,the nonlinear seismic time history response analysis method is used to study the influence of longitudinal stiffness of concrete-filled steel tube tied arch bridge on "non-directional load",the stiffness ratio of arch rib and tied beam,the stiffness ratio of end beams,whether the beams and tie rods are fixed or not,and others factors;(3)Based on the finite element analysis model,under the condition of simply supported system arrangement,the simulation of concrete-filled steel tube tied arch bridge arch bridge under the condition of structural mechanics boundary conditions,basin rubber bearing,lead rubber bearing,friction reduction bearing influence of supports on seismic response of structures and evaluation of seismic isolation effect;(4)Based on the finite element analysis model,taking seismic isolation bearings as the research object,the influence of different bearings' types on the seismic isolation effect of the structure are analyzed.And at the same time,the damping ratio of the seismic isolation bearings and the pre-yield stiffness are analyzed.The parameters such as yielding shear force are analyzed,and the adaptive effect of seismic isolation measures and the principle of seismic isolation measures are obtained for the concrete-filled steel tubular tied arch bridges,which provided reference for similar projects.