Three Dimension Stability And Non-linearity Analysis Of Concrete-filled Steel Tube Arch

At present, concrete-filled steel tube arch bridge is very popular for bridge construction and it will be widely applicable in our country in the future. Based on comprehensive collection of existing research documents in and beyond the country, the element stiffness matrix for three dimension beam element being used in the structure analysis is deduced which is based on virtual work principle, then the expression form of the equation of equilibrium is described when geometric non-linearity and material non-linearity are considered, the constitutive modal is also discussed based on unified theory of concrete-filled steel tube, the stability classifications and instability mechanism of concrete-filled steel tube arch are introduced, the mechanic behaviors and its properties will be well reflected only when the geometric non-linearity and material non-linearity of concrete-filled steel tube arch are considered. By analyzing a half-through concrete-filled steel tube arch with the net span of 141 meters, the effects of which including transverse brace layout, material non-linearity , strength of arch rib material , load distributions and environment temperature fluctuation on the ultimate bearing capacity of concrete-filled steel tube arch are presented, which will be helpful to optimization design and material selection in the actual work.