Research On Digital Precise Measurement Tamping Technology And Application Of Ballasted Track Of Ordinary Speed Railway

There are two main ways to control the linear smoothness of the existing ordinary speed ballasted line（running speed less than 160 km / h）through the large machine tamping operation.One is to carry out the tamping operation with its own measurement system.Due to the inherent defects of the large machine’s own measurement system,this operation mode has residual deviation,can not be accurately repaired for the disease,and can not form a mature and effective operation system;The second method is to measure by artificial level.This method has low measurement efficiency and uneven measurement accuracy according to the level experience of surveyors and the precision of measuring instruments.It has been gradually eliminated by the requirements of rapid railway speed-up and capacity expansion.At present,the digital large machine tamping line operation is carried out in the relative measurement mode of level 0 track inspector,which improves the operation accuracy and quality,and solves the problem that the traditional large machine can not effectively guide the track setting with data.However,the relative measurement mode of Class 0 track inspection instrument also has disadvantages,which can not effectively control the linetype and poor long wave control.On this basis,the absolute + relative measurement mode of "GNSS + inertial navigation" has successfully solved the problem of lack of measurement benchmark,effective control line type and poor long wave control caused by perennial large machine tamping.The focus of this paper is to study the digital fine tamping technology and tamping effect under the absolute + relative measurement mode of "GNSS + inertial navigation".Combined with the case that the large machine tamping operation mode of "GNSS +inertial navigation" is adopted in the construction of EMU reinforcement project from Taiyuan South to Luliang in the Taiyuan middle line in 2021,the construction process and technical requirements of large machine fine measurement and fine tamping are studied and analyzed by collecting relevant research data and reading literature,Research and application analysis are carried out on the principle and operation mode of large machine fine measurement and fine tamping,the layout and control of fine measurement network in the Taiyuan central line,the collection and analysis of fine measurement data,the linear reconstruction,the large machine tamping scheme,etc;Collect the data of track inspection vehicles before and after tamping,and analyze the tamping effect under the absolute + relative measurement mode of the Taiyuan midline by using the TQI value of track inspection vehicles before and after tamping,and compare it with the digital fine tamping effect under the relative measurement mode of grade 0 track inspection instrument in 2020.Through the evaluation and comparison of the operation quality of large machines on the general speed line of public works,the operation quality of large machines tamping under the absolute + relative mode is significantly higher than that under the relative measurement mode,It also meets the requirements of linear control,and the digital precise measurement and tamping can meet the maintenance requirements of ballasted track of ordinary speed railway.