Multi-hazard Risk Assessment on Sea-crossing Suspension Bridge High Pier and Pylon Based on Chain Bayesian Network
With the advancement of technology and increasing demand for transportation,the sea-crossing suspension bridges,as important transportation hubs,are characterized by complex structures and high flexibility.Any damage to these bridges can result in severe consequences.The high piers and pylons,serving as the bridge core load-bearing components,are constantly exposed to the complex marine environments.They are inevitably threatened by various natural hazards throughout their lifecycle,which lead to significant uncertainties in engineering risks.As a graphical model that connects probabilistic reasoning among variables,the Bayesian network is widely used in the structural system quantitative assessment.In view of the present research situation and environmental problems of sea-crossing suspension bridge,this study proposed a quantitative multi-hazard risk assessment method based on Bayesian network.First,the hazard factors were analyzed.The earthquakes,strong winds,and flood-induced tidal scouring were selected as the main hazards,considering the structural and environmental characteristics.The damage level range was determined based on the moment-curvature analysis result,considering the key components or sections of structure.Second,by establishing the hierarchical relation between components or sections and structural system,along with load scenario simulation,the Bayesian network model was constructed to obtain the hazarid risk probability of structural system.Finally,the target system risk assessment was carried out by reference to the risk level matrix and the acceptable risk level of bridge operation.The evaluation result validity was verified by the comparison result under a single load.As an example,the high piers and pylons of Lingdingyang Bridge,currently under construction,were evaluated.The result indicates the risk level 3,which suggests that the structure remains in a relatively safe state during its operational life,although necessary emergency plans should be developed.The result shows that the proposed method can provide theoretical support for multi-hazard risk assessment on similar bridges,and offer valuable guidance for developing hazard prevention and mitigation strategies.
bridge engineeringmulti-hazard riskBayesian networksea-crossing suspension bridgehigh pier and pylonrisk assessment
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