Static And Dynamical Characteristic Analysis And Experimental Investigation On Large Span Half-through CFST Arch Bridges

As concrete-filled steel tubular arch bridges develop in the direction of large-span and lightweight style, the development of CFST arch bridges at home and abroad, as well as the existing arch bridge codes are only applicable to bridges with the span less than 200m.So the study of static and dynamical characteristic for large span CFST arch bridges is in need.In this paper, a large span half-through CFST arch bridge with the span of 280m is discussing, a full-bridge space for static and dynamic analysis of mechanical models is established through the use of the large-scale finite element method software Midas Civil for the research on static,dynamic,elastic stability and aseismic behavior of large span half-through CFST arch bridges. This study will offer a theoretical foundation for development of large span CFST arch bridges design.In this paper, the specific research mainly included several aspects as follows:1,By using the full-bridge 3-D finite element model, the structural stress features considering the construction course of the large span half-through CFST arch bridge are analyzed.It can be concluded that the influence of the construction course for the large span CFST arch bridge should be fully considered.The static failure process of the large span half-through CFST arch bridge under design load is studied to discuss the influence of dead load,automotive load,crowd load,wind load on the structural elastic stability.It can be concluded that as the main load of the structure, dead load controls development tendency of the structural elastic stability safety coefficient.2,Based on the dynamical method of calculation about structure, a research on the natural frequency and natural mode is carried out. It can be concluded that the out-plane stiffness of the large span half-through CFST arch bridge is much smaller than the in-plane stiffness.At last, the aseismic performances of large span half-through CFST arch bridges are studied by using the analysis of response spectrum and the analysis of elastic time-history. the influence of two kinds of methods for structural aseismic analysis and structural seismic response under seismic load of different directions are compared and discussed, It can be concluded that the analysis of elastic time-history should be use on aseismic design of a complex structure with large span CFST arch bridge in high intensity area and earthquake three dimensions input should be considered.3,In this paper, a research on the loading test of the large span half-through CFST arch bridge was carried out. The results indicated that the bridge is satisfactory both on the working performance and on mechanical behavior and they all meet the requirements of the design codes.