Research On Reasonable Construction Period Of PPP Rail Transit Based On Dynamic Buffering Perspective

In view of the complex and difficult construction environment of PPP rail transit project,it is proposed that the influence of various uncertain factors should be fully considered when determining the construction period,and the critical chain project management(CCPM)is introduced to set buffer zone to deal with this influence.Using questionnaire survey and exploratory factor method,41 uncertain factors affecting the construction period of the project are identified.Then,starting from the complexity of construction preparation,the complexity of network planning,the tension of resource use and the risk preference of shield construction,the initial buffer model is constructed by using structural entropy weight method and root variance method.(1)According to the characteristics of complex and difficult construction environment of PPP rail transit Project,it is proposed that the influence of various uncertain factors should be fully considered when determining the construction period of PPP rail transit Project,and the idea of setting buffer by CCPM is introduced to deal with such influence.The questionnaire survey and exploratory factor method were used to identify 41 uncertain factors affecting the construction period of the project.Then,the initial buffer model was constructed by using structural entropy weight method and root variance method based on the complexity of construction preparation,network planning,resource utilization tension and shield construction risk preference.(2)According to the actual performance of social capital in terms of quality,safety and environmental protection during the construction period of PPP rail transit project,the buffer zone dynamic management mechanism is designed to encourage social capital to give play to its technical management advantages.Firstly,according to the Operational Guidelines for PPP Project Performance Management issued by the Ministry of Finance and the existing research results,26 main factors affecting the performance performance in the construction period are identified,and based on this,the performance evaluation index system in the construction period is constructed.Then,the sensitivity analysis of the influence degree of these factors was carried out by introducing system dynamics.According to the actual influence of these factors on the Performance of the project in the Construction period,the buffer dynamic adjustment coefficient CPCwas introduced.Finally,after comparing the actual performance with the set threshold,the buffer size of the project is dynamically managed through the reward and punishment mechanism.(3)By combining the research method proposed in this paper with the PPP rail transit project in n city,it is verified that this method can not only effectively deal with the impact of various uncertain factors on the calculation of reasonable construction period,but also can be used as an effective incentive means for social capital,which is more conducive to promoting the success of PPP rail transit project,and also provides a scientific basis for the government to determine the reasonable construction period The theoretical basis is given.