Research On Initial Cable Tension For Cable-stayed Bridge With Single Pylon

Cable-stayed bridge has become one kind of bridge types which develop faster and appear competitive in modern bridge engineering because of its advantages such as:better bearing capacity,reasonable mechanical systems and beautiful shape etc.As the span becomes larger,structure more various and complex,design and construction income more challenges.Comparing with suspension bridge,cable-stayed bridge has its apparent advantages.One of these is its adjustability in the late stage.Both in the construction stage and the service stage,designers can change bridge's internal force and linetype. without increasing the sectional area and the intensity of the material.As the cable force makes a great effect on the internal force of cable-stayed bridge,it becomes the key of controlling the stress state of bridge. So it is very important to set a rational final state and get proper cable forces for construction stage.How to determine the rational cable force to ensure the safty of cable-stayed bridge has became a very major work in the design of cable-stayed bridge. In recent years, cable-stayed bridge with single tower grows to be widely used to across the urban road and the medium river. So it is very necessary to make some researchs for the cable-force-design of the cable-stayed bridge.In this paper,the Yin Tan XinJiang bridge is modeled by the large finite element software MIDAS CIVIL..After comparing many means for determining the rational final state,minimum bending energy method is chosen to determine the rational state.When getting the rational cable force in the final state,combinating these cable force value with other loads,then analyze the internal force and displacement.In the analysis of the construction state,in order to avoid the factors such as the prestress, shrinkage and creep of concrete,nonlinearity which can bring a different result of using forward analysis method and backward analysis method separately. finally choosing forward iteration method and forward analysis method with considering not closed combining ability to determine the cable force during the construction state.Finally, using MIDAS CIVIL to analyze repeatedly until gaining correct cable force to ensure the safety of the bridge.Through this paper,some references are provided for the usage of the minimum bending energy method and forward analysis method in the cable force design phase.