Abstract:Combining the risk analysis and monitoring measurement system, we identify the factors of risks and determine the risk evaluation index system, the amount of items in various weights was conformed by analytic hierarchy process, then, we introduced the fuzzy theory, the measurement of specific data for fuzzy comprehensive evaluation was completed by creating reasonable membership function, and the comprehensive risk index was obtained through the weights analysis and risk endowing system, thus, we established a dynamic risk assessment model for NATM construction in mountain tunnel. The model can quantify the measured data as a single dynamic risk index, and evaluate the risk of construction dynamically. The dynamic risk assessment system has been applied in Bao Fu highway tunnel, which can reflect the risk of tunnel construction process visually and timely. Analytical results show that the method is reasonable and practical, and is worthy of to be promoted and applied in similar projects.