Multilevel grey evaluation of present bridges

Based on the grey theory, the application of a multilevel evaluation method for the present bridges is discussed. The indexes of the bridge evaluation system are emphatically inquired into, and a practical example to the three present bridges is showed. For the sake of taking effect of all the evaluation information in different grey degrees, disperse information from the experts is handled with weighted vector describing different grey degrees and making single value. At last, three comprehensive values are given so as to arrange in order. The evaluation results state that the multilevel evaluation method can be applied to comprehensive evaluation on the indexes of the bridge evaluation system. The method is objective, reasonable and serviceable to operate. It is beneficial to standardize the management and decision of the present bridges evaluation.