ABSTRACT
The performance of urban bridges gradually deteriorates with the growth of service time because of environmental action and traffic loads. The bridge deterioration prediction model has a significant impact on bridge maintenance effectiveness and saving repair costs. In this paper, a Weibull distribution based semi-Markov prediction model was developed by using the historical bridge inspection records to investigate how do funds allocation and maintenance intervention affect the deterioration process of urban bridges in shanghai. The deterioration behavior of three major bridge parts was compared, and the effect of bridge location was also investigated. The prediction result shows the decay rates of the deck system are the fastest. Moreover, the service life expectancy of bridges in the suburban area is shorter than the downtown area. Therefore, the overall deterioration trends for urban bridges with or without the medium and major repair were predicted based on the investigated actual repair rates. The result shows that the medium and major repair can significantly decrease the proportion of bridges with condition rating 4 and 5, especially for bridges in the suburban area. But the conventional maintenance intervention has a limited overall effect on network-level urban bridges. There is a noticeable trend of bridge degradation from condition rating 1 and 2 to condition rating 2 and 3. Therefore, to reduce the maintenance cost of the entire life cycle of urban bridges in Shanghai, it is necessary to adopt a more reasonable preventive maintenance strategy.
