Analysis On Main Affecting Factors And Optimization Design Of Large Track Maintenance Machinery

Large maintenance machinery serves as one of the important forms of track maintenance which conforms to the tendency of development of railway.It has become more effective and specialized.However,the decision-making system of large maintenance machinery is not normative,which results in that the construction result fails to live up to the expectation.It has become an urgent problem to consider how to allocate the limited large machinery resources and deliver their best performance.In this paper,Beijing-Shanghai line Xingweicun to Xiashu section was chosen as the research object,and general information of track facilities,maintenance and track inspection data were analyzed.By using analytical hierarchy process,paired comparison matrix was applied to determine the weight coefficient of affected factors under the evaluation model of large machinery maintenance.The proposed scheme has been verified by the theoretic calculations.Firstly,this paper summarized the frequency of Track Quality Index(TQI)and the trend of track irregularity in different states,thus achieving the best working status of track.Furthermore,for the key factors involved in the construction process,such as driving safety,occupational safety and transportation schedule,a concrete analysis is required to be made,The results show that the profile optimization design,working status of track before the construction and the construction organization are the main factors that affect the operation of the large maintenance machinery,which should be considered in the optimization decision-making.Based on all these,major conclusions are drawn as follows:(1)Based on the analysis of the inspection over Beijing-Shanghai line,periodic and exponential features were obtained.In certain range of variation of loading,surface standard deviation of 2.02 mm leads to obvious corresponding deterioration for track section,while values of gauge and align standard deviation will not change obviously if they were less than 1.09 mm and 1.66 mm.(2)Besides meeting the requirement of both track lifting and control points,such as bridges,tunnels,and other special points of the line,the bowstring method can better restore the straightness and roundness of railway line.Its optimization effect has been verified practice.(3)Compared with TQI,tamping and shunting index provide better support in deciding large maintenance machinery.For Xingweicun to Xiashu section of BeijingShanghai line,relevant maintenance measure should not be carried out if the tamping index is less than 4.47 mm,and the road diversion index is less than 1.82 mm.On the contrary,the operation quality should be guaranteed as much as possible,so as to improve the track smoothness.Moreover,measures such as cleaning and supplementing ballast are required to improve track structure,so that large machinery maintenance will enjoy a higher quality.