Abstract: In order to intervene unsafe behaviors of workers in construction sites more pertinently, with SIR(Susceptible-Infected-Recovered) as basic prototype, a propagation model (SIR-C) suitable for workers' unsafe behaviors was established to explore communication characteristics of these behaviors and intervention effects. Then, a questionnaire was designed, and impacts of safety education, punitive measures, key figures and inconvenience of work tasks on behavior spreading at each stage were analyzed, and different intervention situations were simulated. The results show that SIR-C model can objectively reflect spreading of unsafe behaviors. In the three stages of imitating, recovering, and forgetting of behavioral communication process, critical factors are key figures, safety education and inconvenience of work tasks. Different intervention effects will be achieved for different types of unsafe behaviors, and that for intentional unsafe behaviors are more obvious. For single stage intervention, that during the recovery phase are comparatively obvious, and moreover, combined intervention effect is better than that of single stage.

Key words: construction worker, unsafe behavior, propagation model, intervention effects, susceptible-infected-recovered-construction (SIR-C)