Research On Progress Management Of Expressway ETC Gantry Project Based On Critical Chain

The expressway network is an important link to promote economic development as it assumes the heavy responsibility of landing road transportation.In recent years,with the rapid development of economy,how to improve transport efficiency,balance various modes of transport,reduce various logistics costs has become a proposition worth further study.In order to promote the development of expressways,further improve the service capacity and level of expressways,and promote the cost reduction and efficiency of logistics,Jiangsu and other provinces took the lead in proposing the "cancellation of provincial toll stations" and the construction of "ETC gantry system" along expressways,aiming at solving the problem of traffic congestion at toll stations and reducing logistics costs.However,due to economic,environmental and other aspects of the restrictions,the project is difficult to construct,the overall period is long,involves a wide range of highway construction safety risk sources,influencing factors and other problems,the traditional construction schedule management method is difficult to effectively solve the above problems.Therefore,it is of great practical significance and social value to study the construction schedule management of ETC gantry system.Aiming at the problem of overdue construction progress of ETC gantry system,this paper first refers to a large number of previous literature,analyzes the key chain theory,and then combines the characteristics of the ETC gantry construction project of Ningjingyan Expressway Company,that is,the utilization rate of key resources in schedule management is not high,resulting in the delay of the construction period.Finally,an optimization method of construction schedule management scheme based on key chain is proposed,and a project management model of ETC gantry construction based on key chain is constructed,and its effectiveness and practicality are confirmed by comparison and verification of engineering examples.(1)The project duration was obtained by using the expert evaluation method,and the initial schedule of the project was formulated.Then the WBS decomposition method was used to decompose the ETC gantry project,and sixteen sub-project processes were initially obtained.At the same time,according to the characteristics of synchronous construction of multiple sections under the jurisdiction of the expressway company,the WBS decomposition optimization method was used to optimize the 16 sub-project processes into 34 sub-project processes.Combined with the logical relationship between the sub-project processes,as well as the low utilization rate of key resources and high cost,the key chain of the project was determined and a new project schedule was obtained.(2)The relationship between equipment resources and human resources and the resources required for engineering is compared,and human resources are established as the conflict resources of this project.A key chain identification method based on complexity coefficient and risk elasticity coefficient optimization is proposed,and a progress management model of ETC gantry project based on key chain is constructed.Then the buffer zone of the ETC gantry construction project of Ningjingyan Expressway is calculated and the setting steps of the buffer zone are described.(3)The buffer zone is monitored by the three-color monitoring method,and the buffer consumption is compared with the completed amount of tasks to achieve effective control of the project progress.By substituting the above model into the ETC gantry construction project of Ningjingyan Expressway,it is analyzed that the progress of the entire project remains highly controllable,and the planned construction period is reduced from the expected 234 days to 181 days,saving a total of 53 days of effective construction period,which demonstrates the usability of the model.Through the above work,the progress management model of ETC gantry construction project based on key chain constructed in this paper enriches the theoretical system of ETC gantry construction project management while optimizing resource allocation and avoiding project overdue.It provides a certain reference for the progress management of other ETC gantry construction projects in the future,so that the progress management level of ETC gantry construction projects is continuously improved.