Research On Risk Mechanism And Establishment Of Risk Assessment Model Of Settlement Risk In Beijing Subway Shield Tunneling Construction

This thesis studied on risk mechanism and risk assessment of settlement risk in Beijing subway shield tunneling construction. Based on the analysis of risk generating process and risk mechanism of settlement, a risk-causing model of perturbation-energy transfer of settlement in subway shield tunneling construction was put forward. Additionally, catastrophe characteristic of settlement risk in subway shield tunneling construction was studied, analyzing the overall process of risks’evolution pathway. By using WBS-RBS risk identification method, the thesis identified the settlement’s risk factors systematically. On this basis, we designed questionnaires on the settlement’s risk factors in subway shield tunneling construction and then gave them out. Factor analysis was utilized to analyze the survey data, and16key risk factors were distinguished. The thesis studied the triangular fuzzy number theory and the fuzzy analytic network process, improving the operation method of solving weight vector in fuzzy judgement matrix on the basis of triangular fuzzy number. The establishment of settlement risk fuzzy network model brings quantitative risk assessment come true. To verify the reliability and the practicability of the model, a subway shield tunneling case history in Beijing Subway Line6was presented. The results indicate that this improved method and model can be efficient in risk assessment.