Study On Life Cycle Risk Assessment Of Bridge Engineering

Since twenty-first Century, with the rapid development of our economy, the transport infrastructure, like the high grade highway, high-speed railway, and urban expressway traffic, has been being constructed largely and bridge engineering has obtained a great opportunity of rapid development. However,the reality that the bridge risk accidents frequently emerged in China cannot be ignored whilst the booming of bridge engineering. Therefore, how to identify and estimate the potential risks of each stage during the whole process of life of the bridge, to select the optimal construction scheme at the planning and design stage, and to give the comprehensive risk evaluation at the bridge construction stage are supposed to be resolved.Based on the research of the bridge risk factors’ identification method,combined with the statistics of 211 bridges accidents at home and abroad, the common risk factors of bridge engineering at various stages were summarized,and constructed a list of risk factors for each stage in bridge whole life, to lay the foundation of further risk assessments.Studying on the current methods of risk-assessment in bridge engineering,the advantages and disadvantages of various methods of evaluation were analyzed, and the multi-objective risk assessment based on the information entropy was applied to the bridge construction project decision-making.Combining with the identification of risk factors at the previous planning and design stage, the risk assessment system with the multi-objective based on the information entropy theory was established to evaluate the bridge construction scheme more objectively, to make a scientific choice and to do further optimization.The comprehensive evaluation method based on the Game theory was introduced to study the weight of each risk evaluation index. And the comprehensive weights, considered both decision maker’s risk will and bridge risk, were obtained by using a theory based on Nash equilibrium of subjectiveand objective weights and entropy principle of information coordination equilibrium. The total risk level of bridge engineering and suggestions of risk decision were given by using a method combined with both comprehensive weight and objective data of risk factors.The game theory of the construction phase risk assessment was used to reasonably determine the comprehensive weight of each risk-index, and then the overall level of risk construction phase was calculated. By defining the Hong-xing River Bridge as background of the system of calculation and analysis,the validity of the evaluation method of risk, at the stage of bridge construction scientific management, was well verified.