Research On Navigation Safety Evaluation Of Submarine Tunnel Exploration And Construction Water Area

With the rapid development of the shipping industry,the number of water construction projects is also increasing.In order to meet the growth of the coastal economy,various complex operations such as hydraulic facilities,submarine tunnels,and water drilling platforms are also increasing,and the resulting water traffic safety issues are gradually becoming prominent.Submarine tunnel exploration engineering is a large-scale offshore operation project,which takes up a long amount of water transportation time and is greatly affected by the marine climate.Its construction environment is influenced by various factors,and there is strong ambiguity and uncertainty.The research content of this article is as follows:(1)Based on the navigation characteristics of the construction water area of underwater tunnel exploration projects,the Human Factors Analysis and Classification System(HFACS)is used to construct a navigation risk identification framework during the construction period,identifying and dividing the risk factors during the construction period of underwater tunnel exploration projects.Based on the selected navigation risk factors and combined with the characteristics of exploration operations,a navigation safety evaluation index system for subsea tunnel exploration engineering is established.(2)A static evaluation method for the navigation risk of submarine tunnel exploration engineering based on mutation theory was adopted to address the sudden changes and fuzziness of navigation risk factors in exploration operation waters.Quantify fuzzy indicators by combining mutation theory with fuzzy mathematics theory;Using the improved CRITIC method to determine the relative importance ranking of indicators.Taking Qingdao Dagang Channel Zone C as an example to evaluate the navigation safety of tunnel exploration projects,it was concluded that the navigation safety risk in the construction water area is at level II,which means the risk is relatively high.Compared with traditional risk assessment methods,the evaluation method based on mutation theory reduces the impact of subjective weighting and can effectively solve the problem of sudden changes in risk factors,thereby achieving static evaluation of navigation risks in engineering construction waters.(3)In view of the limitation that traditional static risk assessment is difficult to describe the dynamic characteristics of risk factors,dynamic Bayesian network is used to carry out the research on dynamic assessment of navigation risk of submarine tunnel exploration engineering.In view of the dynamic and uncertainty of risk factors,a dynamic Bayesian network(DBN)model of navigation risk in exploration waters can be established based on Bayesian theory.Secondly,the fuzzy set theory and improved D-S evidence theory are used to determine the prior probability of nodes,and the weight of nodes is determined by combining the improved fuzzy analytic hierarchy process and entropy weight method.Then,the conditional probability distribution of intermediate nodes is calculated by the weighted distance formula based on probability distribution,which provides a data basis for Bayesian network reasoning.Then,the DBN model is used to predict the probability of maritime navigation risk accidents and quantify the dynamic navigation risk during the construction period.Finally,sensitivity analysis is used to identify key risk factors of accidents,in order to improve the navigation safety level of the operating water area.This study indicates that due to the long construction period,dynamic changes in the scope of work,working environment,etc.dynamic evaluation and prediction of navigation risks during the construction period should be carried out.Dynamic Bayesian network evaluation can represent the time sequence changes of navigation risks in operation waters at different stages during the construction period,can effectively remedy the shortcomings of static evaluation that is difficult to describe the dynamic evolution of risk factors,and can solve the problems of poor predictability and timeliness,and more in line with the evolution law of actual dynamic risks.The model better reflects the changes of navigation risks in the actual construction process.The research results can be applied to control navigation risks during the construction period of similar projects,and have reference significance for the study of maritime navigation risks.