Research On The Mechanism Of How Environment-based Safety Design Influences Workers’ Behavioral Safety

Workers’ unsafe behaviors are the paramount direct causes for construction accidents.However,the root causes can be traced back to design problems in the early stage of construction projects.Design problems incur unsafe working-environment factors,and these factors may cause workers’ cognitive failure towards behavioral safety by influencing their physical and mental conditions.Therefore,if environment-based safety designs are performed in the early stage,prerequisites of workers’ unsafe behaviors will be wiped out in advance,rendering safety management more cost-efficient.To promote prevention through design(PtD),relevant researches laid more emphasis on application aspects.In contrast,PtD has not been well learned yet from theoretical aspects.The mechanism how design influences behavioral safety was rarely addressed in the literature.Existing models depicted the mechanism in vague and simplified ways,which are still difficult to simulate real situations in construction.In addition,design as an abstract concept,was not defined and deconstructed in these researches.Therefore,using questionnaires and safety check records as data input,this paper developed a real-world model depicting the “design-behavior” mechanism based on mature theoretical models.Meanwhile,design was deconstructed into factors and the focal point in design was identified.The content and outcomes of this paper mainly include: 1)Questionnaire data were collected and processed.The “cognition-behavior” model was developed based on theory of planned behavior,which depicted the influencing paths from cognitive failure to unsafe behaviors.2)Safety check records were screened and merged.Different check items were mapped to performance shaping factors(PSF)of cognitive reliability and error analysis method(CREAM).The “environment-cognition” model was developed,indicating how working environment factors exert impact on workers’ cognition towards behavioral safety.3)The concept “design” was deconstructed into factors according to axiomatic theory of design modelling.By semantic mapping,these design factors were linked with CREAM’s PSF to form the “design-environment” model.4)The above three sub-models were combined and nested in the basic feedback loops to constitute a system dynamics model.Through simulations,the patterns that workers’ behavioral safety fluctuates over time were obtained.The most crucial design factor was determined through sensitivity analyses.5)Applying cognitive work analysis as the framework for safety design,design suggestions for potential safety risks were generated.This paper indicates that design factors’ impact on workers’ behavioral safety is mediated by working environment factors and workers’ cognitive factors in a complex and cyclic way.Among design factors,“direct constrains on objects” is the most crucial one with 0.2 impact elastic coefficient on behavioral safety.Besides,fatigue and excessive workload will negatively influence workers’ safety performance,which needs to be considered when conducting safety designs.The methodology used in the paper can be conveniently transplanted to specific projects in various industries,showing its wide applicability and practical value in guiding targeted safety designs to prevent accidents from the source.