用遗传算法确定斜拉桥的恒载初始索力

Determination of Initial Cable Forces for Prestressed Concrete Cable-stayed Bridges with Genetic Algorithm

在设计预应力混凝土 (P .C .)斜拉桥时 ,确定成桥恒载初始索力值是一项重要而困难的任务 ,为此尝试用遗传算法来确定不同目标状态下的斜拉桥初始索力 .以往的方法往往都要假设一个斜拉桥成桥初始内力或位移状态 ,与以往方法不同的是 ,在使用遗传算法的时候却没有这样的要求 ,它只需要一个目标函数即可 。

Determination of initial cable forces under dead load is an important and hard task during the design of cable-stayed bridges.In this paper,genetic algorithm is employed for their determination.The most difference between the methods forwarded in the paper from the old ones is that it is not essential to decide the initial status of inner force or structural displacement.In the genetic algorithm method,only an objection function is needed.The next step is to get the extremum solution of the objection function or the variable values corresponding to the extremum solution.According to the merit mentioned above,theoretically,the method can be applied to get the initial cable forces that can lead to minimal changes of some targets begotten by creep and shrink.