Simulation Research On Safety Capability Of Subway Construction Workers Based On SD Model

With the acceleration of urbanization,problems such as insufficient urban space capacity and congested urban traffic have become increasingly prominent.In order to alleviate traffic pressure,many major cities in China have developed underground space to build subway.At the end of 2017,a total of 56 cities in China’s mainland have begun construction of subways.With the increasing scale of subway engineering construction,subway construction safety accidents are also increasing.And unsafe behavior of constructors is the main cause of safety accidents.Unsafe behavior is the external performance of lack of safety capabilities of constructors.Therefore,improving safety capacity of subway constructors can reduce occurrence of unsafe behavior of construction personnel,and reduce occurrence of safety accidents in subway construction.Firstly,this paper discusses basic theories and domestic and foreign research status such as personnel safety capabilities,system dynamics and structural equation models.It is pointed out that current research on safety capabilities is mainly analyzed from a static perspective,and using system dynamics to carry out the safety capabilities of subway construction workers has not been studied.Through the definition of personnel safety capabilities,operational safety definition for subway constructors is defined.Under the natural micro-environment and management environment of subway construction work surface,constructors use and integrate their relevant skills experience,consciousness and other inherent qualities,aware of potential risk factors in subway construction,so as to correctly judge and take effective measures to control these risk factors,to avoid the unsafe behavior of constructors and subway construction safety accidents.Through analysis of operational definitions and combined with characteristics of subway construction,it is pointed out that the dynamic characteristics of the safety capabilities of subway constructors are obvious;through an overview of the basic theory of system dynamics,theoretically discussed that system dynamics has its unique advantages in solving dynamic system problems.Then,based on operational definition of safety capabilities of subway construction workers,literature survey method and expert survey method were used to construct a system of factors affecting of safety capacity of subway constructors.Structural equation model(SEM)was used to analyze from a static perspective The relationship between influencing factors of safety capacity of subway constructors,and the weight of each influencing factor was obtained according to path coefficient between the influencing factors.On the basis of relationship between influencing factors of the safety capacity of subway construction personnel analyzed by SEM,the system dynamics method was constructed.Finally,constructors in Chengdu Metro Line 11 was selected for empirical analysis.The simulation results show that safety capabilities of subway constructors slowly rise in the first 8 hours,and decrease rapidly in the next 4 hours.Through comparison and simulation,it is found that organization and management of the first-level influencing factors have a significant effect on improving the safety capacity of subway constructors,which can effectively slow down the decline in safety capacity of subway construction personnel in the later stage of work.Effect of the second-level influencing factors of constructor’s individual characteristics on improving the safety capabilities of subway constructors has no obvious difference at the beginning of work.The intensity of construction operation plans and the level of safety supervision in the secondary influencing factors of organizational management have a significant effect on improving the safety capability of subway constructors.The effect of safety capability is significant.The noise level of the construction site and the microclimate environment in the secondary influencing factors of construction environment have a significant effect on improving the safety capability of subway constructors.This paper combines SEM and SD models to build a simulation model for safety capacity of subway constructors to study evolution of safety capacity of subway constructors,and draw out intervention strategies to improve safety capacity of subway constructors.Related research results help to improve the theory and methods of personnel safety,and can effectively improve safety capabilities of subway constructors and reduce occurrence of subway construction safety accidents.