Research On Ultimate Bearing Capacity Of Concrete Filled Steel Tube Arch Bridge With Truss Section

CFST arch bridge has developed a lot in recent years, but there is not a well-established analysis system for this kind of bridge. From the work done by now, we know that: in aspect of stability analysis, branching-point stability is often calculated instead of extreme-point stability and the geometric non-linearity is often ignored. In addition, model experiment is carried infrequently which leads to the shortage of cognition of in-plane stress of CFST arch bridge, especially the kind with truss section;it is needed to make sure the influence of section design on the ultimate bearing capacity of CFST arch bridge.Main work in this paper is listed as follow:1. Based on the theory of elasto-plastic large displacement finite element analysis method, the rigidity equation of 3-D layered composite beam element is get to established the program of calculating the ultimate bearing capaticy of CFST arch bridge.2. The whole process of in-plane ultimate bearing stress of CFST arch bridge with truss section which includes collapse shape and the rule of stress alteration is studied to work out the collapse characteristic of in-plane ultimate bearing stress.3. A simplified method of utility for calculating ultimate bearing capacity of CFST arch bridge with truss section is presented and it is proved to be practical.4. The effects of different design parameters, like ultimate bearing capacity calculating theories, core concrete constitutive relations, load distributions, steel grade, concrete grade, steel ratio and the length-height ration of arch rib on the ultimate bearing capacity are studied.The results of this thesis provide a basic reference for the future research work and revision of the design guidance for CFST arch bridges.