Research On Subway Project Construction Schedule Management Based On Key Chain

Urban rail transit is becoming the main means to solve the problem of urban traffic congestion.As people's demand for urban rail travel continues to increase,urban rail transit will also inevitably enter the most rapid development stage in the next few decades.As of the end of 2018,a total of 63 cities have been approved for urban rail transit network planning.The total planned construction line length is 7611 kilometers(excluding open operation lines),and the scale of planned and under construction lines has steadily increased.At the same time,the construction progress of subway construction projects is not optimistic.The traditional schedule management methods commonly used in the construction of subway projects often change plans and delays,hindering the smooth implementation of the project,and the key chain management technology can greatly improve this situation.Therefore,this article Based on the theory of schedule management,the following researches have been done on the construction progress of subway projects in China:(1)Identify key chains.Using domestic and foreign research theories on key chain project management as the basis for identification,the key points and difficulties of the subway project schedule management are specifically analyzed,the advantages of the key chain are introduced into the subway project schedule management,and the process duration is estimated in conjunction with the triangular fuzzy number,Heuristic algorithm is used to balance resource conflicts and key chains are identified.(2)New method of buffer setting.According to the actual situation of the subway project,the difference between the 95% truth degree and the 50% truth degree of the fuzzy construction period is used to estimate the safety time of the process,and a variety of uncertain influencing factors are comprehensively considered and improved on the basis of the root variance method The calculation formula of the buffer.(3)Improve the monitoring model of the buffer zone.According to the 4M1 E theory,the influencing factors of the construction period are decomposed,and the index weighting is implemented using the G1 method.In combination with the cloud theory,a process feedback early warning model for construction delay control is established.By setting a buffer warning method,the construction project is delayed Dynamic monitoring and prevention control.(4)Case analysis.Take Xi'an Metro Line 9 as an example to verify the rationality of establishing a model to improve the progress management of key chain projects,and through Monte Carlo deduction and simulation,compared with the traditional project schedule management model,verified the use of subway project schedule management The improved critical chain method has a higher execution rate;at the same time,the actual simulation of the construction delay control model constructed by the application is carried out,and the risklevel determined by the cloud theory is general,and the construction plan determined by the key chain technology is still within the control Conclusion.Based on the original model,this paper establishes an improved key chain schedule management model.Research shows that this model can effectively promote the improvement of the subway project schedule guarantee system and make up for the defects of traditional schedule management methods;on the other hand,it can be better To deal with the difficult problems in the construction process of subway projects,to guide the smooth implementation of the project,has certain application value.