A Risk Evaluation Method with an Improved Scale for Tunnel Engineering

Analysis and evaluation of risks in tunnel construction is commonly performed using various scales; however, such scales have serious limitations. In this paper, an improved scale based on a fuzzy analytic network process is proposed. An exponential scale is introduced to assess the risks, and a method is proposed to determine the importance parameter for the exponential scale. Through the combination of the exponential scale and the triangular fuzzy number, a fuzzy exponential scale is proposed and is utilized to construct pairwise judgment matrices. The improved fuzzy analytic network process is used to establish a general method for risk analysis in tunnel engineering, which is applied to the risk analysis of the Humaling tunnel. The results from the proposed method more accurately reflect the actual situation than those of the analytic network process using the 1–9 scale.