Application of Interval Extension Theory in Evaluating Bridge Condition

In order to better reflect the service condition of the bridge and solve the problem that many subjective factors and uncertainty of the indexes weights existed in current bridge condition evaluation, based on the interval extension theory, the grading evaluation model for bridge condition by combining experts’ subjective weights and objective weights was established in this paper. This model used IR correlative function of interval extension theory to evaluate the bridge condition, and the results could be showed accurately by giving quantitative value. Additionally, the influence of expert’s subjectivity on evaluation results was reduced by use of the combination weight, which improved the evaluating reliability. An example indicates that this model can give better evaluation results and reflect the comprehensive state of bridge condition more perfectly and objectively.