文档介绍：Optimization of Cable Tensioning in Cable-Stayed Bridges
Le Hong Lam1,Nguyen Huy Cung2,Vu Hong Nghiep2
1 Hohai University,Nanjing(210098)
2 Ho Chi Minh City University of Transport,Vietnam.
E-mail:nguyenhuycung@, lhlam@
Abstract
During the structural analysis of cable-stayed bridges, some specific problems arise that are not
common in other types of bridges. One of these problems is the derivation of an optimal sequence for
the tensioning of the stay cables. This paper describes a novel solution to this problem. Finite elements
are used for modeling the bridge structure. Numerical examples are presented, which illustrate the high
obtainable accuracy of the method.
Keywords:cable-stayed bridges,optimization,finite element,catenary cable element

1. Introduction
In the design cable-stayed bridge, an important step is determining the tensioning forces of stay
cables to achieve a desired geometry of the bridge after construction, especially under the reaction of
dead load. Many structural analysis techniques were proposed to solve this problem. The different
models of cable have been investigated.
The elastic cable is assumed to be perfectly flexible and possesses only tension stiffness; it is
incapable of pression, shear and bending forces. When the weight of the cable is neglected,
the cable element can be considered as a straight member. But under action of its own dead load and
axial tensile force, a cable supported at its end will sag into a catenary shape. The axial stiffness of a
cable will change with changing sag. When a straight cable element for a whole inclined cable stay is
used in the analysis, the sag effect has to be taken into account. On the consideration of the sag
nonlinearity in the inclined cable stays, it is convenient to use an equivalent straight cable element with
an equivalent modulus of elasticity, which can well describe the catenary action of the cable. The
concept of a cable equ