Research On Construction Period Management Of Subway Underground Excavation Station Based On Critical Chain Technology

With the development of society and the expansion of cities,the traffic congestion in big cities is getting more and more serious.Subway because of its large capacity,punctuality,fast features,by more and more cities of all ages.At present,the MTRC has become the primary means of solving traffic problems in mega-cities.Due to its construction,the underground tunneling station can not occupy the current roads and is gaining popularity in the Beijing area with good address conditions.However,underground tunneling station costly,complex process,the construction process of unpredictable factors,the project schedule management often delay the phenomenon of construction.Currently in the subway project duration management,the general adoption of the Critical Chain Method.The delay in the duration of any process on the key line will result in a delay in the total project duration.Due to the small construction work surface,the cross-cutting process and the progress of the construction due to the change of formation,the construction schedule of each construction process on the key line will often be delayed due to many factors,so the total construction period is difficult Guarantee.In recent years,Critical Chain Method began to rise.Critical Chain Method is a significant improvement over the traditional critical path approach.compression of the duration of each process redundancy(usually only 50% of the completion of each process set the guarantee period),and set the buffer at the end of the project.through the management of the buffer zone to achieve the goal of controlling the total project duration.In Critical Chain Method,the duration of any process on a critical route is compact,and the duration delay of a single process is allowed.As long as the sum of the delay in each process does not exceed the buffer time,the total duration can be guaranteed without delay.The use of Critical Chain Method,can greatly save project duration,project duration guarantee rate.However,in the underground tunnel station construction period management,the direct application of Critical Chain Method will encounter serious problems.The construction schedule of subway tunneling station not only needs to guarantee the total project duration,but also some key nodes in the project implementation period.For example,arranging underground tunneling stations in the overall planning of the entire project without the shield receiving conditions prior to the arrival of the shield machine would be unacceptable even with no delay in the total length of the station.Therefore,the "milestone time" abandoned by Critical Chain Method in the traditional critical path law is of great significance to the project management of the subway project.This paper studies the use of Critical Chain Method technology subway station excavation schedule construction.Through the optimization of the traditional Critical Chain Method technology,the concept of "milestone buffer" was proposed in the buffer setting phase.Two concepts of "progress delay coefficient" and "progress delay index" were proposed in the buffer management phase in order to shorten the construction period The purpose of the cycle.