Study On The Treatment Measures Of Rail Corrugation In Curved Track Based On The Rail’s Dynamic Characteristic In Curved Track

With the rapid development of urban rail transit, a lot of vibration absorber fastenings are utilized in order to reduce the vibration and noise induced by the train operation. However, the vibration mitigation sections occur serious rail corrugation, which will influence the trains’safety and the passengers’ comfort. Rail grinding is the most common measure to treat rail corrugation and fastening replacement is also employed to treat the rail corrugation in vibration absorber fastenings section by Beijing Metro. Meanwhile, rail corrugations have close relation to the track parameters. It is necessary to study the effects that rail grinding and track parameters have on the rail corrugation. The paper combines the test data analysis and numerical simulation to study the above problems.Firstly, the simulated train loads were obtained from the vertical and horizontal acceleration of the curved track that tested in the rail corrugation section of Beijing Metro Line10. Analyze the characteristic of the wheel/rail force and make the comparison analysis on the influences of rail grinding and fasteners replacement have on the dynamic response of wheel/rail force. The results indicated that the dominant frequency of the lowrail’s horizontal force is170Hz,230Hz and430Hz, and that of highrail’s horizontal force is1701Hz and230Hz, and that of lowrail’s vertical force is170Hz,230Hz,430Hz and1000Hz, and that of highrail’s vertical force is170Hz,330Hz,500Hz and1000Hz. Rail grinding could reduce the dynamic responses of the horizontal and vertical forces largely, however, it is not all the frequency and the effect of only part peak frequency band is obvious. Replacing the III type vibration absorber fastening with the GJ-III fastening have certain slowing effect on the dynamic responses of the vertical wheel/rail force’s peak frequency band, but have certain amplification on the dynamic responses of the horizontal wheel/rail force.Then, the orthogonal experimental design and the simulated train load in the before rail grinding working condition were adopted,9numerical models were built to calculate the influences of different track parameters have on the rail’s dynamic responses, and to carry out the parameters significance and optimization analysis. The results indicated that the peak frequency of lowrail’s vertical acceleration and velocity is230Hz, and330Hz, that of lowrail’s horizontal acceleration and velocity is170Hz,230Hz and330Hz, that of highrail’s horizontal and vertical acceleration and velocity. The dynamic responses of the horizontal and vertical displacement is large below10Hz. Train speed have the most significant influence on the dynamic responses of the curved track, and the lateral fastening stiffness arid curve radius have the large influence on the horizontal dynamic responses of rails, and vertical fastening stiffness have the large influence on the vertical dynamic responses of rails.Finally, the paper make the comparison analysis on the effects of the two corrugation treatment measures of the rail grinding and fastening replacement from the rail’s dynamic responses. It can be obtained: Rail grinding could reduce the dynamic responses of the rails’acceleration, velocity and displacement largely, however, it is not all the corrugation frequency and the effect of only part peak frequency band is obvious. Replacing the III type vibration absorber fastening with the GJ-III fastening have good slowing effect on the dynamic responses of the rails’acceleration, velocity and displacement in part of peak frequency band, but have certain amplification on the dynamic responses of within the peak frequency band of the highrail’s horizontal acceleration and velocity, and lowrail’and highrail’vertical displacement. The effects of the GJ-III fastenings should be taken into account compressively.