Study On Life Cycle Risk Assessment And Countermeasure Of Long-span Cable-stayed Bridge

In recent years,driven by a series of major projects,China's bridge construction level has been leap-forward development,in the design technology,construction technology and other aspects are entering the ranks of the world's leading.However,there are many risk factors in the safety assessment and risk management,especially for large-span bridges with complex construction conditions,high construction time,long service life and poor operating conditions.There are many risk factors in the whole life cycle.Only for a bridge design,construction or operation of a stage to carry out risk assessment,and for large span bridge to carry out life cycle risk assessment and risk management strategies related research is rarely seen.A risk event is an event that occurs at a low probability but causes a consequence or loss.Because of its long line length,many components and outstanding structural characteristics,large span bridges need to consider the influence of multiple uncertain small probability factors in the whole life cycle.Based on the existing research results at home and abroad,this paper expounds the theoretical framework of the risk assessment of Highway Bridge and the practical construction of Huaiyu Xijiang River Bridge.Based on the practical experience of the actual highway bridge risk assessment,the key technical problems of the whole life cycle risk assessment of the bridge are explored and studied.The main risk events of the project planning stage,the structural design stage,the construction stage and the operation management stage of the long-span cable-stayed bridge are identified and the corresponding risks are given Control measures.The main work of this paper is as follows:(1)Risk assessment and countermeasure of project planning stage of long-span cable-stayed bridgeBased on the understanding of the construction site,hydrology and geology of Huaijie Xijiang Bridge,the possible risk factors such as abnormal weather,earthquake disaster and flood risk are analyzed,and the risk factors of construction condition are evaluated.On the risk of construction conditions to develop risk control measures.(2)Risk assessment of structural design of long span cable-stayed bridge and its countermeasuresBased on the risk source analysis of the structural design scheme of the double-tower central cable-stayed concrete beam cable-stayed bridge,the risk source which may exist in the structural design is identified,and then the risk is evaluated on the basis of the risk source.The structure of the program risk control measures.(3)Risk assessment and countermeasure research on construction technology of long span cable-stayed bridgeThrough the analysis of the uncertain factors influencing the normal activities in the construction and implementation of the Huayi Xijiang Bridge,it is concluded that there may be a risk source in the construction technology,and the possible risks in the construction technology are evaluated.On this basis,Technical risk control strategy.(4)Risk assessment and countermeasure research on operation and management of long span cable-stayed bridgeThis paper studies the possible risk sources,such as bad weather,environmental impact,traffic safety accident,ship impact,vehicle operating load and structural durability,during the operation and management stage of the construction of Huaiyu Xijiang Bridge.The risk of the operation stage is evaluated.Risk Control Countermeasure in Operation and Management.