Research And Design In The Section-Optimization Of The Middling And Small Span Bridges

In recent years, highway-construct has developed highly in our country, many roads and bridges have been built. In the bridge-construct, middling and small span bridges are the majority. How to design well and truly, fleetly, economically and rationally is the designer's desired goal. Repeated design is the conventional method. It searches a satisfying result with the process suppose-analyze-check-redesign. This method is built on the experience of the designers but the external engineering-condition. The result is stochastic. Under this background, my paper put the applied task forward which is to optimize the bridge section. Bridge section optimization belongs to engineering optimization. The conventional optimization method is not fit for the engineering optimization because of the specialty of itself. Genetic Algorithm (GA) is one of the main directions in today's compute science. Its application in structural catches more and more attention. It has a peculiar ability of bionic simulation with relaxed optimal conditions and better optimization results, the author introduced this method in the research program.Based on a great of literature, this paper analyzes and summarizes the genetic algorithm for the design of structural optimization. The basic conceptions and primary characteristics are introduced in this paper. This paper discuss some primary factor when genetic algorithm applied on optimal design, for example the mathematical model the constrained problem,the initial population and the controls parameter of genetic algorithm .Then, the section optimization model based on the engineering cost is built for reinforced concrete T-cross beam, PC concrete T-cross beam, part PC concrete T-cross beam which are constructed largely. A tool for T-cross optimization was accomplished with MATLAB and Visual C++. After the analysis of the result between the example and the optimized result, GA is founded to be in effect and feasible for T-cross beam optimization. At last, design suggests for T-cross beam were presented based on the optimization analysis. The conclusion from the paper can be the reference for the construct designers in the real design projects.