Determination Of Reasonable Finished State And Reasonable Construction State Of Special-Shaped Tied-Arch Bridge

Special-shaped tied-arch bridge, which was brought forward firstly in China, is a novel bridge type whose reasonable arch axis is dissymmetric curve as all cables are inclined to a certain slope. The reasonable arch axis make different by the rate of inclination of suspenders.The special-shaped tied-arch bridge becomes a popular bridge type with the priority to be selected owing to its novel and aesthetic appearance. The dissymmetric arch axis diverges a lot from the line of pressure caused by self-weight of the arch, which is different from the general tied-arch bridge and makes the construction procedure hard to control. As a result, it is necessary to research mechanical behavior and determinate the reasonable finished state and the reasonable construction state.Many studies have been carried out about special-shaped tied-arch bridge based on Huangbo Liuyang River Bridge. The synthetic method of determination of reasonable finished state about Special-shaped tied-arch as follows: determinate drafted structure dimension →determinate preliminary finished state by the least bending strain energy method →calculate the live load stresses of the tie girders →deduce the most pre-applied force →layout effective prestress →calculate the feasible range of bending influenced by live load →adjust the cable force in order to keep the value of stresses of concrete less than or equal to limited value by optimization model → check the reasonable finished state.The construction procedures of special-shaped tied-arch bridge with framing are complex. For example, it is dangerous in naked arch state. So the key to determination of reasonable construction lies in determination of tensioning occasions and cable forces. In the thesis, multiple cable force modifications are determined by optimization model whose object function makes maximum stress least in construction. At last those cable forces carried out the construction control of Huangbo Liuyang River Bridge.The coefficient of cable force is amended by the method of fluid pressure operated jacks and load transducer and natural vibration frequency. The method is feasible because the errors are less than and equal to the limited value by comparingthe measured values with the theory values. The result of construction control is good through the comparison results of measured value and theoretical value about height marks and cable forces and stresses.The temperature field of the tie girder and ring created by the sunshine are measured. The pattern of vertical temperature gradient caused by sunshine in tie girder is exponential function.From the results of loading test, we can see that the bridge is in good active state.