Survey on intensity of physical work of workers with different tasks in railway tunnel construction using wearable energy consumption meter

Objective This study aimed to investigate the intensity of the physical work of workers with typical tasks in railway tunnel construction in order to provide support for scientifically monitoring workers’ health.

Methods From July to August 2022, 24 workers with different tasks (3 electric welders, 7 erectors, 4 waterproofers, and 10 steel bar workers) were recruited in tunnel construction site. Their physical activities were recorded for 24-hours for 3-5 consecutive days using the energy consumption meter on the dominant wrist. The intensity of physical work was estimated based on counts per minute, energy consumption, and metabolic equivalent. One-way ANOVA tests were used to compare differences in the intensity of physical work among different workers.

Results Finally, 23 workers completed the investigation. Except for the maximum counts, significant statistical differences were detected in total counts, average counts, and counts per minute among the waterproofers, steel bar workers, electric welders, and erecters (P < 0.05). Particularly, the activity meter value of waterproofing workers was the largest (P < 0.05). The energy expenditure per unit time for the four types of work was (1 303.0 ± 78.5), (760.8 ± 24.5), (554.8 ± 91.4) and (521.9 ± 30.4) kcals (1 kcal = 4.184 kJ), and the differences between the groups were statistically significant (F = 5.72, P = 0.006); the metabolic equivalents were (2.89 ± 0.22), (2.57 ± 0.39), (1.81 ± 0.07) and (1.70 ± 0.27) METs, respectively. The differences between the groups were statistically significant (F = 6.99, P = 0.002).

Conclusions The intensity of physical work varied greatly among workers with different tasks in railway tunnel construction. The intensity of physical work of the waterproofers was equivalent to Level Ⅲ(heavy intensity), while Level Ⅱ(medium intensity) was for the other workers. The manager in tunnel construction should pay attention to the differences in intensity of physical work among workers with different tasks, reasonably set labor quotas, and allocate human resources for protecting workers’ physical and mental health.