Theory Analysis And Segment Test Study Of The Ultimate Load Capacity On Concrete Filled Steel Tubular Arch Bridge

This paper is based on Maocaojie Bridge which is located in the Yiyang City of Hunan Province, combines with the model ultimate bearing capacity load test of the arch ribs segment with concrete filled steel tube(CFST), the model scale is 1/5 This paper studies the model ultimate bearing capacity of CFST in plane including geometrical and material non-linearity and studies the model ultimate bearing capacity of CFST in space including material non-linearity, the following work is done:1 Introduces the common ways of calculating geometrical non-linearity in plane, then considers the engineer reality, the influence of initial internal force through making use of geometrical stiffness matrix, change coordinate the influence of large displacement, the influence of geometrical non-linearity to the ultimate bearing capacity load of CFST Result indicates: the pure geometrical non-linearity has a little effect on the ultimate bearing capacity load of CFST2 Consider the interaction between steel tube and concrete, the restriction of steel tube to concrete is included in stress-strain relation ? Element is divided into sub-element which can reflect the changing of stiffness along the length of element exactly Two program are compiled, one program can calculate the ultimate bearing capacity load of CFST in plane which considers geometrical and material non-linearity and the other program can calculate the ultimate bearing capacity load of CFST in space which considers material non-linearity., In the latter program, calculating model is based on sub-element, such as, the element stiffness matrix is made up of the sub-element stiffness matrix, the remains force of node in element consists of the remains force of node in sub-element. One way in which the structural is divided into NELEM element and every element is divided into ND sub-element, despite the influence of geometry factor, its calculating precision is equal to another way in which the structural is divided into NELEMxND element The program results for the old element are compared with the experimental data, which proved the programming procedure is correct. On the base of the above, analyze the influence of parameter such as restriction coefficient and the intensity of concrete to the ultimate bearing capacity load, conclusion is drawn and which can provide reference for engineer,,3 Combine with the model ultimate bearing capacity load test of Maocaojie Bridge, at first ..calculate the initial stress redistribution arising from core concrete creep(continuance two years), then compare the ultimate bearing capacity, in which one consider the initial stress and the other does not consider the initial stress, result indicates: the initial stress will low the ultimate bearing capacity load of concrete filled steel tube arch bridge to some extent 4 On the base of above analyze, put forward some problem worthy of studying more...