Study On The Risk Evaluation Of Submerged Floating Tunnel In The Gulf During The Operation Period

The risk assessment is one of the vital problems in the preliminary study of construction project. The reason for project losses may be the risk oversight or incomplete consideration, but the unpredictable risks contributing more. As a new traffic structure, floating tunnel has less impact on the surrounding compared with other sea-crossing channels, as well as all weather operations and energy conservation.However, the danger should not be disregarded. It has been the important link to analyse risks and choose evaluation methods for the development of submerged floating tunnel.Firstly, the article summarizes theoretically the concept, structure and risk assessment of the floating tunnel.Secondly,based on the the current operation situation of submarine tunnel domestic and overseas, risk factors existing in operation process of submerged floating tunnel are found out aiming at characteristics and operation circumstance of it. Then the evaluation index system of the floating tunnel in operation period is established by matter element extension method.Thirdly, because of incompatible problems consisting in the risk evaluation of submerged floating tunnel and relatively few indicators, the thesis has established the matter-element evaluation model by the use of entropy-based weight method and AHP (analytic hierarchy process) based on the matter element extension pattern. Then the matter-element evaluation model of submerged floating tunnel in the operation period is built on these grounds.To illustrate qualitative indicators quantitatively, indicators are analysed quantitatively by extension set and correlation functions.The index weight of the submerged floating tunnel risk evaluation index system is determined by the integrated weighting value method which is composed by entropy method and expert weighting value. In this way the advantages of subjective and objective weight are combined, which makes it scientific and reasonable for weight determination.Finally, the model is applied to the Qiongzhou Strait project. Analysing the risk level of three schemes in the operating period-the submerged floating tunnel, submarine tunnel and crossing bridge draws a conclusion that risk control of engineering structural, third party damage and finance must be reinforced. Then the corresponding extension risk measures have been formulated.The thesis conducts a deep research on the operation circumstance of submerged floating tunnel and find out the risk factors of it. Based on the risk evaluation theory, it has solved the problem of quantitative research on risks in the tunnel operation period with the hope of offering the policy-making basis for managers and developer.