Guizhou Duohua Cable-stayed Bridge Reasonable Status And Construction Control Research

In recent years,the transportation industry in southwestern China has developed rapidly.In order to cope with the special topography of the southwestern region,China has built a number of large-span bridges in the mountainous areas of southwestern China.The composite beam cable-stayed bridge has been widely used in the economically underdeveloped southwest mountainous area because of its good wind resistance,structural beauty and strong spanning ability.Based on the background of the large-span cable-stayed bridge under construction,the Duohua Super Bridge,several issues in the design and construction control of reasonable state determination,non-linear effects,and parameter sensitivity analysis were studied.Provide a basis for a smooth construction.The main research work of this article is as follows:1.A brief introduction to the composite beam cable-stayed bridge,and on this basis,the finite element method is used to establish the basic and construction process calculation model of the Duohua Super Bridge2.Use the zero displacement method and the practical method of cable force optimization to determine the reasonable cable force of the cable-stayed bridge.By comparing the cable force calculation results obtained by the two methods,the final reasonable cable force and the reasonable state of the bridge are determined.3.Based on the commercial finite element software Midas/Civil,the reasonable construction cable force and construction status of the cable-stayed bridge can be determined.Based on the reasonable bridge formation status,the unstressed control method is used to determine the reasonable construction cable force to improve the calculation efficiency and accuracy4.Compile the cable stress-free length calculation program,and review the accuracy of the calculation program based on the parameters of the cable-stayed cable of the built bridge.The results show that this program only needs a few iterations to complete the solution of the unstressed length,which greatly improves the calculation efficiency of the unstressed length SO.5.By comparing the calculation results of several typical working conditions,it is further shown that the non-linearity has a greater influence on the dead load effect during the construction process and the internal force envelope during the completion of the bridge.Non-linear effects can make the calculation results more accurate6.The parameter sensitivity analysis of Duohua Super Bridge was conducted,taking the self-weight of beam section,structural stiffness,cable force of stay cable as parameters,and by changing the above parameters(uniform overweight,over-tension,under-tension),the amount of parameter change was analyzed Influence on the cable-stayed bridge’s completion status The calculation results further show that the self-weight of the beam section and the cable force of the stay cable have a greater influence on the bridge completion than the rigidity factor.Study the influence of the self-weight of the beam section and the random error of the cable force on the cable-forming effect,and understand various structural performance indicators in a probabilistic sense,so as to achieve a more reliable assessment of the structural condition and construction control.