Shift Work and Labor Productivity in Urban Sewer Construction

Sewer construction in urban areas often has significant effects on work zone traffic control, traffic flow, and safety. Contractors typically introduce night shifts to meet contract schedule and reduce traffic congestion. However, there is a lack of understanding of how shift work is associated with labor productivity in sewer construction. This research investigated labor productivity of 10 major activities in sewer and drainage construction in Ho Chi Minh City, Vietnam, when these activities were performed in both day and night shifts. Levene's tests and t-tests were employed to analyze the data and investigate the research hypothesis. Results revealed that four activities were significantly sensitive to shift work and the other six activities were not. Pavement cutting and timber piling activities had higher productivity in day shifts. In contrast, steel sheet piling and manhole concreting were more productive in night shifts. Labor productivity of excavation, formwork installation, rebar fabrication/installation, pipe installation, sand filling, and asphalt pavement was not significantly different between the two shifts. The results were verified by the experienced site managers/engineers through structured interviews. The findings from this paper help contractors effectively manage their sewer projects by allocating resources appropriately to construction activities between the day and night shifts.