| During the "14th Five-Year Plan" period,my country has entered a new stage of development,and the development of circular economy has become a major strategic deployment.In recent years,the process of urbanization has been further accelerated,and the construction industry has developed vigorously.However,the total amount of construction waste is increasing,the utilization of construction waste is insufficient,the resource recycling and reuse system is not standardized,and the extensive production management method has not undergone a fundamental change.,The overall utilization rate of construction waste resources is not high.As a part of the circular economy,construction waste is an urgent problem to be solved in scientific and rational management,reducing the probability of project risk occurrence and effectively improving the resource utilization rate.Therefore,this paper takes the construction waste recycling PPP project as the research object,analyzes the relationship between internal and external factors of the project system,and discusses the risk evolution law in the whole life cycle.further development.Through the whole life cycle theory and system theory,the paper identifies the risks of construction waste recycling PPP projects,and conducts a systematic causal relationship analysis,simulates the project risk changes in the whole life cycle,finds out key risk factors,and proposes relevant measures.（1）This paper uses the literature research method as the main method,supplemented by the ABC classification method,to identify risk factors.On the basis of literature statistics,the risk factors affecting the construction waste recycling PPP project were initially identified;Data were collected by questionnaire survey,risk values were calculated,risk factors were corrected and screened by ABC classification method,36 key influencing factors were finally determined and divided into seven risk types.Based on the macro,medium and micro perspectives,the risk types of construction waste resource utilization PPP projects are further summarized,including government-level risk,market-level risk and project-level risk,and the risk index system of construction waste resource utilization PPP projects is established.（2）According to the system dynamics modeling idea,analyze the causality of government-level risk,market-level risk and project-level risk subsystems in detail,reveal the internal relationship of the system,draw the causal loop diagram of subsystems at all levels with the help of Vensim software,and make qualitative analysis of the risk causality of each subsystem of construction waste recycling PPP project;By reason tree analysis,the system boundary risk is defined and the method of estimating the initial value of the risk is determined.Questionnaire survey was used to collect data,and the weight of each risk factor was calculated by using the sequence relation method.With the help of logical function,the system dynamics equation was established,and the risk evolution model of construction waste resource UTILIZATION PPP project was constructed.（3）Based on the above research,take the construction waste recycling PPP project in City C as a column for analysis.The expert investigation method is used to estimate the initial value of the boundary risk,and the Vensim software is used to test the correctness and validity of the model;through the simulation simulation,the risk change trend of each subsystem in the whole life cycle of the project is dynamically predicted;the sensitivity analysis method is used to analyze the boundary risk The degree of influence of factors on project risk,and determine the key influencing factors.In view of the development of the construction waste recycling PPP project in City C,measures are proposed from the perspectives of the government,the market and the project to provide a theoretical basis for decision makers,and then promote the smooth implementation of the construction waste PPP project.Figure [29] table [17] reference [74]... |
