Selection Of Bridges Strengthening Measures And Funds Allocation Strategy

In china, because of such factors as the increase in the weight of vehicles and serious environment, several bidges have deteriorated considerably in recent years. Thus, repair or strenghtenting of these bridges is essentiall for the sake of safe. In the other hand, a great many of funds are needed in the period owning to the china's high speed ecomomic developing. And the funds are limited for the strengthening of bridges. It is the best way that developing a strategy for the funds allocation and selection of streagthening measure on the systemic and economic viewpoint. Based on the bridges' reliability, the article manages to obtain the best benefits for the limited funds through deciding the bridges' strengthening priority, degree and means and arranging the funds for the deteriotative bridges. The road net is disassembled three levels. The first level is called road net. The second one is called line, and the last one is called bridge. Taking the degree of reliability as harmonized parameter and cost as separated one, it settles the suitable relation between the three levels. On the level of road net, the crucial lines are selected according to the function of road net. Subsequently, reliability and working life of line are optimized as varialble until the most return of limited funds. On the level of line, depending on the parameters of line, such as reliability and working life, reliability of bridge are optimized in order to the least expected expense, and the working life is same between the bridge and the line. On the level of bridge, according to the parameters of the bridge, the reliability of elements are obtained, and the suitable maintaining and strengthening measure also could be found for cost rninizau'on.This paper develops two important functions. One expresses the relationship of time and the degradation of resistance; another is the relationship of resistance and expense depending on the maintaining and strengthening measure. Because of these functiones, a connection is established between strengthening cost and the degree of reliability. The result could be obtained through the multi_test. This article gives the model and example of each level. It is proved that the Genetic algorithms (GA) is effective for this problem. From the analysis of the paper, the acceptable strengthening measures and funds allocation could be obtained for ecery bridges based on the whole benefits of road net through the the strategy.