基于模糊变权TOPSIS的桥梁状态评估方法

A Bridge Condition Assessment Method Based on Fuzzy Variable Weighted TOPSIS

为降低传统桥梁评估中存在的主观性与不确定性,提出基于模糊变权TOPSIS的桥梁状态评估方法。首先,采用梯形模糊数对底层指标的评价值进行定量描述,探讨正、负理想解的绝对化与模糊化;其次,以变权理论为基础,研究指标变权权重的确定方法;然后,结合水平截集理论,计算在不同水平截集取值下的相对贴近度区间,并对结果进行去模糊化处理,建立桥梁状态等级划分标准。最后,应用建立的方法体系对昆山玉峰大桥进行状态评估,对评估结果进行分析并提出维修养护对策。结果表明:改进TOPSIS降低了评估中存在的主观性,提高了评估的可信度。

A modified bridge condition assessment method based on fuzzy variable weighed TOPSIS is proposed to reduce the subjectivity and uncertainty in the traditional practice.Firstly,the trapezoidal fuzzy number is adopted to quantitatively describe the bottom indicators,and the absolutization and fuzzification of the positive and negative ideal solutions are discussed.Secondly,the method of determining variable weights is explored.Thirdly,the fuzzy interval arithmetic of relative closeness is developed usingλlevel sets,followed by the process of defuzzification to obtain the final value,which is regarded as the bridge comprehensive evaluation result.And the grading standard for bridge conditions is established.Finally,the condition assessment of Kunshan Yufeng bridge is conducted.The assessment results are analyzed and maintenance countermeasures are advised.It is shown that the modified fuzzy variable weighted TOPSIS method helps to reduce the subjectivity in bridge assessment and improve the reliability of the assessment.