Identification and Assessment of Occupational Risks in Mechanized Excavation of Metro Tunnel using the Failure Mode and Effects Analysis Technique (FMEA)

The construction industry is known as one of the most dangerous industries in terms of work-related mortalities, injury rates, and compensation payment to workers. Therefore, assessment of safety risks is a key step to be performed in management of major construction projects. In this study, the occupational risks of Qom metro line an excavation project were identified and assessment.
In this descriptive case study, the Failure Mode and Effects Analysis (FMEA) technique was used to analyze risks. In data collection process, observation, worker's experience and judgments, checklist, standards and regulations, as well as incident records were used. Risk detection capabilities, severity, probability, and consequences of hazards were determined by professional experts in various team works. The identified risks were prioritized and corrective actions were recommended.
In the present study, the project was divided into 12 different working units. Generally, 49 activity titles associated with these 12 units were determined. Eventually, 293 risks associated with these activities were identified. Risk levels of the identified hazards included 26 cases at low risk level, 202 cases at moderate risk level, and 65 cases at high risk levels. After implementation of corrective actions, regardless of the three hazard cases at moderate risk level, the remaining identified hazards were reduced to a low risk level.
The results of this study indicate that using the FMEA technique to assess the occupational risks of mechanized tunnel excavation projects was very suitable. Furthermore, with a strong FMEA team a significant reduction in risk level of the project will be achieved.