Analysis Of Improvement Law Of Track Alignment And Height Irregularity In Precise Tamping Operation

With the continuous increase of the speed and the train running density in China,the use of tamping machines to carry out maintenance and repair operations for the ballast track has become an important mode of maintenance.By analyzing the effect of track irregularity improvement after tamping operation,it is found that,due to factors such as the error of tamping operation and measurement system,the different structure of tamping position,and the difference of ballast density,the actual adjustment is not consistent with the calculated adjustment in actual tamping operation.Usually,the works department will appropriately increase the adjustments to improve the quality of operations based on experience,which will lead to a certain blindness in the precise-tamping scheme.Therefore,how to obtain the adjustment coefficient accurately is of great significance for improving the tamping quality.The paper takes the track alignment and height as the research object,and establishes a regression model for calculating the adjustment coefficient.Firstly,based on the analysis of a large number of orbital inspection data,the correlation between the calculated adjustment of the orbital deviation before the operation and the actual improvement of the orbital deviation after the operation is analyzed,and the correlation coefficient between the variables is solved.And the correlation degree of the variable is judged.Secondly the linear regression model is established according to the linear relationship between the two variables.Afterwards,the rationality and applicability of the regression model are confirmed by the significance test.Finally,the adjustment coefficient is applied to the engineering practice.And the difference in track regularity is compared between the additional adjustment coefficient and the unadjusted adjustment coefficient to verify the effectiveness of the model.Regression modeling analysis of measured track data shows that the confidence interval of lateral deviation adjustment coefficient at 95% confidence level is [1,1.1].It indicate that the track alignment regularity is better after the tamping operation.According to the actual situation,it can increase 0~10% horizontal adjustment.The confidence interval for vertical deviation adjustment coefficient is [1.3,1.5] at 95% confidence level.It indicate that there is insufficient amount of vertical adjustment in lifting operation.According to the actual situation,it can increase the track lifting value about 30% to 50%.The adjustment coefficient of vertical deviation was applied to the engineering examples.The results showed that the improvement effect of high amplitude irregularity and overall standard deviation were more significant in the line with an adjustment coefficient,and the track tamping quality by tamping machine has been improved.