Research On The Rational Completion Status Of Cable-stayed Bridges Based On The Influence Matrix Method

The cable-stayed bridge has been one of the chief types for long span bridges due to its large span capability, structural simplicity, beautiful figure and good economic benefit. It has spread to all over the world in a half century. The cable-stayed bridge is composed of three basic components of cable, tower and girder. As we all know that cables of the cable-stayed bridge are tension members, while the tower and girder are flexural members. Its working principle is using the cables, which connect to the tower, as elastic supports of the girder so as to decrease the maximum bending moment of the girder, reduce the dead weight of the girder and improve the span capacity of the bridge. Later controllability is one of the important characteristics of cable-stayed bridge, namely the structure stress state can be changed into the best working state by adjusting the cable forces without any increase in material. How to determine the reasonable cable forces becomes the most important question to determine the rational completed status of the cable-stayed bridge. This paper introduces the calculation methods and research significance of two kinds of cable forces involved in the design process of the cable-stayed bridge: the rational final cable forces and the rational initial cable forces.The first chapter of this paper shows the development situation of the cable-stayed bridge and the current research status of cable forces both at home and abroad. The chapter2and chapter3respectively presents the calculation method of rational final cable forces and rational initial cable forces which are based on the influence matrix theory. This methods rationality and advantages are elaborated compared with the traditional calculation method in this paper. In the chapter4the accuracy of this calculation method has been verified through the analysis of the si-yang bridge. The results show the method based on the influence matrix theory is practical and reliable, which has certain directive significance for the design and construction of the cable-stayed bridges.In the last chapter of this paper, the conclusion gives us a summary and outlook for this paper. We puts forward some hardly consider factors in this paper like nonlinear problem of the long-span bridges. And looking to this method can be applied to other similar bridges, for example, the bowstring arch bridges or the suspension bridges.