Abstract: DTVI₂ fastener is the most common used fastening system in Beijing Metro, and demonstrated as a stable system by long term usage. However, unexpected rail corrugation occurs on DTVI₂ fasteners sections in a new open metro line. In order to provide a treatment solution for this unexpected problem, tuned rail damper (‘TRD’ for short) is proposed to suppress the growth of rail corrugation by installing. The demonstration test track is conducted in a section of Beijing Metro Line 6, which is suffering serious rail corrugation. TRDs are mounted at both sides of rail in the test track section, while the rail remained the original state in the control section. A measurement campaign is conducted to compare the direct rail frequency response prosperities and the decay rate of track for both sections. The results indicate that the dynamic properties of DTVI₂ fastener track are optimized by TRD. For one side, some resonant peaks (such as the vertical resonant peak at 209 Hz and the transverse peak at 845Hz etc.) are removed and the vertical/transverse first-order pinned-pinned resonance response amplitudes are decreased by 23%/25% shown on the frequency response curves. For the other side, the damping characteristics are significantly improved at 200~5 000 Hz. The vertical decay rate curve achieves the maximum growth of 16 times at 315 Hz, and the transverse one is 8 times at 160Hz. In addition, the growth of rail roughness was also traced for a period of more than 456 days after the installation. The monitoring data shows that the corrugation is already serious in the control section and the typical wavelengths of the corrugation are 25~80 mm. However, the rails basically remain ‘silent’ in the test track section. Therefore, TRD is demonstrated as an effective solution for suppressing the growth of such rail corrugation occurs at DTVI₂ fastener track sections.

Key words: DTVI₂ fastener, metro, rail corrugation, tuned rail damper