| With the 40 th anniversary of the reform and opening up,China's bridge construction has developed rapidly and suspension bridges have sprung up.In today's bridge engineering,suspension bridges have strong spanning capabilities and are suitable for construction in lakes,rivers,deep valleys,deep trenches and other terrains.They have many advantages such as clear stress,high material utilization,good anti-seismic performance,attractive appearance,and convenient construction.It is also one of the best bridge types with a span of over 1000 m.However,during the operation process,suspension bridges are often faced with risk factors such as the harsh natural environment and heavy transport tasks.Preventing and controlling risk factors is a key problem that must be solved for the safe operation of the suspension bridges.To solve this problem,First of all,it is necessary to comprehensively evaluate the operational risk of in-service suspension bridges,and to analyze risk factors,and propose risk control and Prev ention measures.Which have very important theoretical and practical significance.Firstly,this paper established a comprehensive evaluation index system that includes natural disasters,man-made disasters,and accidental disasters.In these three aspects,the index system includes 16 specific indicators,which basically include the various risk factors of suspension bridges during the operation period.Subsequently,a multi-layer fuzzy comprehensive evaluation mathematical model for operating risk of in-service suspension bridges based on improved AHP and entropy weight was established.When the comprehensive weight values of risk indicators were established in the evaluation mathematical model,the traditional AHP and entropy method were first performed.Optimize and improve,and use MATLAB math software to make the subjective and objective weight results more accurate and reasonable.Then,based on the distance function and the minimum relative information entropy principle,the comprehensive weight values of each index are calculated.The comprehensive weights combine the subjective weights calculated using expert experience and the information between the data to avoid the subjectivity that is caused by the use of AHP defect.Finally,using the comprehensive evaluation mathematics model established in this paper,a case study of Xinlong Bridge in Yunlong County of Dali Prefecture in Yunnan Province was conducted.According to the results of fuzzy comprehensive evaluation,the degree of impact of various risk sources on the safety operation of suspension bridges was found,and the overload risk was found to affect the safe operation of suspension bridges.The key source.The finite element software was used to simulate the suspension bridge during the operation phase based on the risk sources of overloading,and the degree of influence of the overload of key risk sources on the safe operation of the suspension bridge was clarified.Finally,corresponding risk control and prevention measures are proposed for each risk source.The research results show that the risk index system and fuzzy comprehensive evaluation mathematical model established in this paper are accurate and reasonable.At the same time,there are many risk sources in the suspension bridge during operation period.It should be based on the principle of prevention and comprehensive management,and it should be combined with each other.The actual situation of the bridge proposes corresponding targeted control measures.In addition,the research content of this paper also has certain reference significance for risk assessment of other bridge types. |
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