Research On Calculation Methods Related To Track Vertical Profile Irregularity Of High-speed Railway

High smoothness of the track plays a crucial role in ensuring the high speed of the train.How to ensure the track having a good regularity is the core of high-speed railway technologies.At present,the detection of high-speed railway track geometric status is based on track control network.Examining the smoothness of the railway is achievable by means of automatic total station and Railway Inspection Instrument.With the help of Railway Inspection Instrument,the smoothness parameters which can reflect the geometry state of track can be achieved.Such as gauge,level(high),twist,vertical irregularity,lateral irregularity and the absolute deviation.In recent years,with the introduction of Railway Inspection Instrument,the research and exploiture on it has been advancing in domestic country.How to carry out the evaluation and the calculation of track irregularity is a key point.At present,the evaluation and calculation of the track irregularity of high-speed railway is mainly based on the experience of domestic general-speed railway and early high-speed railway technologies of foreign countries.Domestic and foreign scholars have put forward various methods to calculate the track irregularity,especially the medium and long wave irregularity.Based on the summary of previous studies,firstly,the paper discuses the difference between domestic evaluation methods and foreign evaluation methods.secondly,the paper has studied on the principles of the definitive algorithm,which based on three-dimensional coordinates and the approximate algorithm,which based on their lateral and vertical profile absolute deviation values and the approximate algorithm,which based on normal offset.And then comparative and statistical analysis were carried out to those irregularity values calculated by the algorithm metioned above.At last,in view of the train having different sensitive wavelength of vertical irregularity at different speed.this paper deduces a definitive algorithm of vertical irregularity of arbitrary wavelength.On the other hand,due to the development and history of high-speed railway in China is not very long.The examination and calculation of track geometric irregularity are carried out according to the method which used at the construction period of high-speed railway.With a wide range of high-speed railway being builded,it is necessary to do some research on the test method and standard in the operational and maintenance period of high-speed railway.In the operation and maintenance period,due to the inspection and maintenance skylight time is very short,how to detect and evaluate the track geometric status completely and accurately is a problem that should be solved quickly.In this paper,methods improved were presented which applies to detecting and calculating the values of track irregularity on the basis of analyzing and researching the method which used at the construction period.Firstly,in order to improve the efficiency of field measurement,extending distance between two station and two measure point was adopted;secondly,calculating values of track irregularity based on the longitudinal section design parameter reconstructed was adopted in order to reduce the amount of the adjustment of track.Theoretical analysis and experiment show that methods improved are feasible and effective on improving efficiency in operation and maintenance period.