Based On System Dynamics Model Of The Rail Transit PPP Project Risk Conduction Mechanism Research

In 2018,China's urbanization rate reached 59.58%,and the urban population surged to 831 million.The increasing urban population has brought great challenges to urban public transport.In order to solve the problem of people's daily travel,major cities have increased the planning and construction of urban rail transit.With the advantages of environmental protection,safety,speed and punctuality,urban rail transit has gradually become the preferred mode of public transport for people's daily travel.However,the construction of each rail transit line often needs huge financial support.Government finance alone can not meet the construction needs.In this context,PPP(Public-Private-Partnership)model emerged as the times require,and has become an effective model to solve the government financial problems and improve the service quality and efficiency of urban rail transit.However,with the large-scale development of urban rail transit PPP project,many management problems hidden in the construction of urban rail transit in China are increasingly exposed.As a kind of project with high risk and uncertainty,the risk of urban rail transit project in all stages of its life cycle will change in varying degrees under the influence of the internal and external environment of the project.Although the current domestic and foreign academic research on risk management has formed a relatively perfect theoretical system,but the research on the source of risk and the changes in the process of communication is relatively weak.In order to further improve the research system,this paper takes risk transmission as the starting point,and systematically studies the risk mechanism and transmission path of urban rail transit PPP project.The research results have important reference significance for formulating scientific and efficient risk management strategies.Based on modern risk management theory,risk transmission theory,system dynamics and other related theories,in order to systematically and comprehensively study the transmission process of the main risk factors in the whole life cycle of urban rail transit PPP project,this paper takes risk transmission as the center of the research content,and according to the concept of risk transmission,main influencing factors and risk transmission in urban rail transit PPP project.The risk conduction model of rail transit PPP project is constructed based on process change characteristics,and the management plan is formulated according to the model analysis results.In this paper,firstly,the research theory of risk transmission is introduced and its concept is defined.Then,on this basis,the generation of risk factors and the way of transmission are explored,and the level and steps of this study are clarified to determine the risk transmission network formed in the process of risk transmission.Then,the risk transmission network model of PPP project of urban rail transit is constructed.From qualitative analysis to quantitative research,the risk evolution of each node at a certain time is simulated by risk transmission network module,and the project risk level is predicted.Finally,combined with the simulation results of risk transmission,a relatively perfect risk management system is formulated for how to effectively control and avoid risks.Through the above research,it is analyzed that the risk of each stage of the rail transit PPP project shows a clear upward trend with time,and shows a slowing trend with the passage of time.At the same time,the risk status of different stages is mainly related to The coupling results of the forward edges at this stage are closely related,rather than simply adding,and the risk state of each stage is transmitted to all backward stages through the diffusion effect.This paper starts from the risk conduction aspect to explore the risk management system,can visually observe the process and law of the change between various risk factors,and help to further understand and grasp the impact of risk on the whole project from the perspective of the whole process,so that it is better.Control and manage project risks.This research has important reference value for risk control of urban traffic track PPP projects in operation.