Influence Factor Analysis For Line Shape Of Concrete Self-anchored Suspension Bridge

Self-anchored suspension bridge owns pretty appearance like the traditional suspensionbridge, also it is very economical,and can adapt almost all the topographic and geologicconditions, it has been one of the competitive bridge type. At present, most of theself-anchored suspension bridges use reinforced concrete beam. But the line shape of theconcrete self-anchored suspension bridge is difficult to control in construction. For theresearch of the influence of natural factors (temperature, shrinkage and creep, foundationsettlement), non natural factors (construction and installation error) to the whole bridge arefew, therefore there are many uncertainty factors. How to effectively control the line shape ofthe self-anchored concrete suspension in construction, has already been an important problemto solve. So it is necessary to analysis the factors which effects on the line shape of theconcrete self-anchored suspension bridge.This paper researches calculation method and theory on concrete self-anchoredsuspension bridge, involve the line shape of the beam and the cable loaded and unloaded.Then uses finite element program established the numerical simulation model, studies theinfluence of factors. The factors studied include: natural factors like shrinkage and creep ofconcrete, temperature, foundation settlement; unnatural factors like the construction error ofthe initial alignment of the main girder and cable, material characteristic error of the girder,error of the system conversion. Through analysis, the main conclusions are as follows:(1) The influence of the concrete shrinkage and creep of natural factors is a long-termimpact, the shrinkage and creep of termination time does not end of after10years, to extendthe stiffening girder loading age properly can improve the situation, the foundation settlementis little, but the influence of the internal force can not be ignored.(2) Through the calculation and monitoring results of the actual bridge, the systemtemperature effect on the line shape of the concrete self-anchored suspension bridge is moresensitive than the effect of temperature gradient.(3) The initial line shape of the stiffening girder and cable，the length without stress ofthe cable plays a decisive role in formation of line shape of the concrete self-anchoredsuspension bridge. In order to calculating the initial line shape of the stiffening girder, a sufficiently accurate theoretical prediction should be made on the bulk density of thestiffening girder, also the influence of shrinkage and creep of the concrete, settlement offoundation should be considered. During the construction period, in order to reduce the errorof construction effect on the bridge line shape, the quality of construction and precision ofcontrol should be ensured.