Quantitative risk evaluation for construction methods using accident rate analysis based on working days by occupation

Construction projects are among the most dangerous workplaces in modern industries, and the choice of construction methods is highly relevant to worker safety. Therefore, construction project managers must consider safety when selecting a construction method. This paper proposes a procedure for quantitatively calculating the risk of construction methods to provide a reliable indicator for construction project managers. This study was conducted in four steps: (i) Data collection and classification, (ii) calculation of accident rates for each work breakdown structure (WBS) level, (iii) calculation of man-day-based accident rates by occupation type, and (iv) calculation of accident rates for construction methods. When the accident rate per worker was calculated based on man-days, the occupation type related to scaffolding had the highest rate. Finally, the calculation results of the accident rate by construction method using the proposed method confirmed through quantitative metrics that the traditional steel-reinforced concrete (SRC) method has an accident rate approximately 2.6 times higher than the prefabricated steel-reinforced concrete (PSRC) method. The results of this study propose a procedure for calculating the accident rate by occupation type per man-day for each construction method, which is difficult to compute using quantitative methods. This paper provides reliable metrics for decision-making in the selection of construction methods for construction project managers with decision-making authority and proposes a quantitative risk assessment and comparable procedure based on the actual resources required for the various alternative methods.