Risk Analysis of Underground Tunnel Construction with Tunnel Boring Machine by Using Fault Tree Analysis and Fuzzy Analytic Hierarchy Process

Abstract

Tunnel boring machines (TBMs) are preferred for constructing tunnels, particularly for underground mass transit railways, because of their speed, minimal environmental impact, and increased safety. However, TBM tunneling involves unavoidable risks, necessitating careful assessment and management for successful project completion. This study presents a novel hybrid risk-analysis method for tunnel construction using TBMs. The proposed method integrates fault tree analysis (FTA) and the fuzzy analytic hierarchy process (fuzzy AHP). FTA was employed to calculate the probabilities of risk occurrences, while fuzzy AHP was utilized to determine the consequences of the risks. These probability and consequence values were used to calculate continuous risk levels for more accurate risk analysis. The proposed method was applied to a real case of metro line construction. The results demonstrated that the proposed method effectively analyzes the risks, accurately reflecting decision support data. The risks were categorized based on the continuous risk levels in descending order. The most significant risk was the deterioration of the TBM. The benefits of this study provide project managers and stakeholders involved in underground construction with a new risk-analysis method that enhances work safety and facilitates the timely execution of urban tunnel construction projects.