Research On Risk Evaluation System And Construction Risk Evaluation Of Underwater Tunnel

In recent years, underwater tunnel has been developing rapidly in China. Because underwater tunnel has more uncertainty, more constructed technology, higher request of construction and greater risk of face, the risk evaluation research of the underwater tunnel is significant.Firstly, the paper analyzes the theory and method of the risk evaluation, which processes: risk connotation, risk identification, risk estimation, risk assessment; studies the basic connotation of underwater tunnel risks, the risk evaluation process, the theoretical framework and the index system of the risk evaluation; and establishes the risk evaluation system of the underwater tunnel on the basis of the theory and method of the risk evaluation.Secondly, the main risk factors of the underwater tunnel construction are identificated with the expert investigation method. The construction risk evaluation index system is established by the Analytic Hierarchy Progress method (AHP).Considering the fuzzy in risk estimation, the thesis resolves the quantification issue by fuzzy theory. Basing on R=P×C Model, which both considers the collective effect of risk factor probability and loss, the thesis ascertains the risk level of essential factor. Risk level of each step is ascertained by fuzzy synthetic evaluation method.Finally, with the Liu Yang River Underwater Tunnel in Chang Sha, the paper carries out the risk evaluation of the construction of the Liu Yang River Underwater Tunnel, gets the overall risk levels of the Liu Yang River Underwater Tunnel construction and further provides the basis of the risk control.