Safety Risk Assessment And Control Of Prefabricated Building Construction Based On System Dynamics

As an important direction of the upgrading and transformation of China’s construction industry,prefabricated buildings have the advantages of high efficiency,economy and environmental protection.However,the development of prefabricated buildings in China is still in its infancy.The types of safety risk accidents in the construction process are complex,and there are problems such as immature methods and inadequate management,which to some extent hindered the promotion of prefabricated building.Therefore,comprehensive and objective construction safety risk assessment and targeted high-effect response measures are very important,which can provide guarantee for the rapid development of prefabricated buildings.Therefore,this paper studies the safety risk of prefabricated building construction based on system dynamics.In the course of the study,using the method of combining theory with practice,qualitative and quantitative,the causal relationship feedback diagram is constructed to confirm the interaction between risk factors through the feedback loop analysis.It is helpful for us to scientifically and reasonably evaluate the safety risk of prefabricated construction by creating a flow chart of risk assessment combined with the actual situation of the project.Based on this result,a series of targeted risk control measures are given to minimize the construction safety level,which has important practical significance.The specific work is summarized from the following aspects:(1)On the basis of consulting a large number of literature,this paper compares the construction process of prefabricated buildings and traditional cast-in-place buildings,analyzes the safety management characteristics of prefabricated building construction,summarizes the characteristics of construction safety accidents,selects and combs the construction safety risk factors and divides them into five subsystems according to 4M1E theory,namely,human risk,material risk,mechanical equipment risk,management risk and environmental risk.On this basis,a list of safety risk factors for prefabricated construction is constructed and interpreted.(2)Using the system dynamics simulation software Vensim to construct the causal relationship feedback diagram of the safety risk of prefabricated construction,and taking the human risk and management risk as the key research objects to analyze the feedback loop of the relationship between risk factors,it is concluded that the feedback loop is mostly self-reinforce positive feedback.(3)The final weight of each risk factor is determined by G1 method and entropy weight method,and the flow chart of risk assessment is constructed.Combined with actual project,the safety risk simulation of prefabricated building construction is carried out to show the change law of safety risk with time.When the risk values of each subsystem are reduced by 5%and 10%respectively,it is obtained that the human risk has the greatest impact on the safety risk of prefabricated construction,and it is also the most vulnerable.The second is management risk,material risk and mechanical equipment risk,which is consistent with the above weight calculation results,proving the correctness of the paper.(4)The safety risk management of prefabricated building construction is a complex system and may produce risk superposition.Therefore,on the basis of expounding the safety risk control theory,we put forward qualitative countermeasures.The optimization model of safety risk control is constructed.In the case of limited resources,the reasonable allocation of investment costs can quantitatively and effectively improve the safety level.