Analysis and management of risks experienced in tunnel construction

摘要

In this study, first of all, the definitions of "risk", "risk analysis", "risk assessment" and "risk management" were made to avoid any confusions about these terms, and significance of risk analysis and management in engineering projects was emphasized. Then, both qualitative and quantitative risk analysis techniques were mentioned and within the scope of the study, Event Tree Analysis method was selected in order to analyze the risks regarding TBM (Tunnel Boring Machine) operations in tunnel construction. After all hazards that would be encountered during tunnel construction by TBM method had been investigated, those hazards were undergoing a Preliminary Hazard Analysis to sort out and prioritize the risks with high scores. When the risk scores were taken into consideration, it was seen that the hazards with high-risk scores could be classified into four groups that are excavation + support induced accidents, accidents stemming from geologic conditions, auxiliary works, and project contract. According to these four classified groups of initiating events, Event Tree Analysis was conducted by taking into care four countermeasures apart from each other. Finally, the quantitative and qualitative consequences of Event Tree Analyses, which were undertaken for all initiating events, were investigated and interpreted together by making comparisons and referring to previous studies.