Study On Construction Safety Risk Assessment And Prevention And Control Measures Of Prefabricated Buildings

In recent years,with the acceleration of China’s industrialization and urbanization,assembly has become a new trend in the development of China’s construction industry.Due to the late development of prefabricated building in China,there are many safety problems,such as immature operation skills of operators and inadequate management of managers.Among them,there are many factors influencing the safety risk in the construction stage and their mutual relationship is complex and changeable,especially in the construction stage of the assembly project construction process.Therefore,it is of great significance to carry out systematic and dynamic safety risk assessment and put forward prevention and control measures in the construction stage of prefabricated building projects.The occurrence of safety accidents is often not the result of a single risk factor,each risk factor is in a system,they interact with each other,so as to have an impact on the whole safety risk system.Based on the theory and construction safety risk management theory as the theoretical basis,from the safety accident characteristics and "4 m1e" principle,from personnel,management,objects(materials,equipment,technology and environment five aspects of prefabricated building construction safety risk analysis,and through the questionnaire survey method and grey correlation method to screen the risk factors,Finally,25 main influencing factors were screened out,and the construction safety risk evaluation index system of prefabricated buildings was constructed.Combining system dynamics model with prefabricated building construction safety risk,the weight of prefabricated building construction safety risk index was determined by improved analytic Hierarchy Process（IAHP）and entropy weight method（EWM）,and the causality diagram of safety risk was drawn according to risk factor analysis.The initial value and influence coefficient of risk factors were determined by expert scoring method,the system dynamics equation was written,and the risk evaluation model composed of five risk subsystems including personnel,material,management,technology and environment was constructed.Finally,Vensim software is used to simulate and evaluate the construction safety risk level of prefabricated buildings.The results show that five factors,including personnel,management,technology,material and environment,affect the construction safety of prefabricated buildings to a certain extent.Among them,personnel risk and management risk have the greatest impact,followed by technical risk and material risk,and environmental risk has a relatively small impact.Finally,in order to further explore the impact of safety risk factors on the system,sensitivity analysis was used to determine the key factors,and then targeted to put forward the assembly building construction safety risk prevention and control measures.