Study On Risk Allocation Of PPP Projects In Underground Utility Tunnel

With the rapid development of urbanization in our country,the problem of serious load of urban underground pipe network is becoming more and more serious due to the increasing of urban population.The road is excavated repeatedly in the process of expansion,renewal and maintenance of municipal pipelines.On the one hand,it seriously restricts the rapid development of the city,on the other hand,it also threatens the safety of peopleundefineds lives and property.In recent years,the city underground utility tunnel has been actively promoted and constructed by local governments throughout the country.Its biggest disadvantage is that it is 1-2 times more expensive than the traditional way of direct burial,and the huge funding gap cannot rely solely on limited government finance.The cooperation of government and social capital to seek win-win PPP model has become the first choice for financing the underground utility tunnel construction.It has the characteristics of complex participants,large capital investment,long construction and operation cycle,and complex risk factors,etc.how to reasonably distribute the project risk is the key to the success of the project.Only by establishing a scientific and reasonable risk sharing mechanism can the sustainable development of the underground integrated plumbing PPP project be guaranteed.Under the background of the urgent need for the construction of underground utility tunnel in the present urban development,this paper summarizes the current research situation at home and abroad from the two perspectives of underground utility tunnel,PPP project risk management and introduces the PPP model,underground utility tunnel,risk allocation three aspects of the theoretical basis.By comparing the common risk identification methods,the paper identifies 56 risk factors in 8 categories,such as political risk,market risk and so on,which are combined with literature statistics,case analysis and expert interview.The principal component analysis(PCA)was used to screen out the key risks and remove the correlation between them.From the perspective of social capital,this paper classifies whether the risk needs to be shared by the risk preference game model,so as to determine the risk factors that need to be shared by the project participants.Under the condition of complete information,not only the dynamic risk-sharing game model based on bargaining game is constructed,but also the dynamic risk-sharing game model is constructed within the project company composed of government and social capital.At the same time,the static risk-sharing game model within the social capital association composed of n social capital parties is constructed,and the risk ratio between the government and the social capital parties is solved.This paper takes the PPP project of Shiyan underground utility tunnel as an example,after the original risk list is deleted by questionnaire,the 30 risk factors of PPP project in Shiyan underground utility tunnel are identified.By using principal component analysis,20 key risks are selected,and 10 risks that need the government and society to share with each other are established based on the risk preference game model.By using the bargaining model,the risk ratio of the government and the social capital is calculated,and the feasibility of the risk sharing model between the government and the social capital is verified2It provides a reference for government and social capital to make decision.