Risk Analysis of Automated Excavation Operations by Energy Trace Barrier Analysis Method

Background and aims: In automated excavation operations especially excavating big tunnels with high operation speed the application of Tunnel Boring Machine (TBM) has been prevalent. Tunneling construction projects especially TBM excavating operations have experienced some accidents in recent years. Hazard control must be done through the process of risk management. This study was done w ith goal of risk analysis of automated excavation operations in one of the water transfer tunnel projects. Methods: In this study for risk analysis, energy trace and barrier analysis technique was used. In data gathering process were used observation method, worker experience and judgments, checklist, standards & regulations and incident records. Recognition of energy sources, targets, probability and severity of hazards were done by competence experts in various team works. The identified risks were prioritized and control measures were recommended . Results: In this study 51 hazardous energy sources in 6 energy categories were recognized. These identified energy sources included physical energy 29.4%, chemical energy 19.6%, mechanical energy 41%, electrical energy 8% and natural energy 2%. The crane section by 19.5%, shield by 10% and cutter head by 10% were the most and the least dangerous part of tunnel boring machine in excavation process. Conclusion: Based on the findings of the study, TBM operations include various energy sources. Energy trace and barrier analysis technique can be used effectively in risk analysis of TBM operations.