The Research Of Construction Optimization Of Large Span Steel Truss Bridges Based On Genetic Algorithm

With the development of bridge construction in our country, some large span continuous steel truss arch bridges with single-arch emerge. This kind of bridge has characteristics of structure novelty, long span with cantilevered assembling method, large height from ground, and complex installation. It is required that using the facility of large temporary bearing piles, suspension cable mast, creeper crane and surcharge in the course of steel girder construction. Additionally, the internal stress arose from the installation of steel girder will directly impact the mechanics capability of completed bridge. To safely erect steel girder with high quality, it's necessary to calculate all kinds of control construction state, serving for assistant design of structure and the craftwork parameters of steel girder erection.According to the example, in this thesis the improved genetic algorithm is combined with computation of buckle-cable adjusted. And the genetic optimization model based on real number encoding is introduced. In the established model, rank-based fitness assignment selection and dynamic penalty strategy are introduced to handling restriction problems. In order to establish the genetic optimization model to get the optimum value of parameters and apply them to the course of structural analysis of construction phases, the author analyzes the adjustment of cable length and suspender tension in all kinds of construction phases and releases the restriction of structure with multi-variable and multi-restriction. The result shows that this model can be conveniently and practicably used and meet the construction and design precision.The research is an application of bran-new intelligent computation theory in the construction control field of bridges by optimizing the force of cables and suspenders. It will offer important data and valuable references for the construction control of large span continuous steel truss arch bridges to assure safe construction, the mechanical capability of completed bridge in reason, and appropriate route. Furthermore, the theory and methods the research has got will afford good technical support to the construction of the same bridge style.