On the optimal design of cable-stayed bridges

This paper studies cable-stayed bridges (CBSs), with special focus on the initial force distri-butions in cables during construction phases. An algorithm for the optimal design of the pre-tensioning sequence of cables is presented. A procedure for the optimization of cable forces is developed, according to a given objective function. Particular attention is given to the choice of the parameters to be optimized, and numeric examples are provided. The proposed method is employed to study the At Tannumah bridge in Basrah, Iraq; and is suitable for the optimi-zation of the pre-tensioning sequence of arbitrary cable-stayed bridges. We show in the rest of the paper that an initial design (named S0 configuration) that does not include any pre-tensioning forces in cables can lead to a highly non uniform bending moment distribution over the deck; which is not ideal for an optimal structure. Fort that reason we develop an “optimal design” (named Sd configuration), that corresponds to pre-tensioning forces inducing an “optimal” bending moment distribution over the deck.