A MEASUREMENT CAMPAIGN TO INVESTIGATE THE EFFECT OF USING SOFT RAILPADS ON GROUND-BORNE VIBRATIONS FROM UNDERGROUND RAILWAYS

Abstract

Railway networks may run through or beneath populated regions and significant landmarks. Hence, the ground-borne vibration caused by the trains might affect nearby buildings, residents, and the sensitive equipment within these buildings. Accordingly, accurate and thorough vibration assessment and measurement campaigns are necessary to confirm that train-induced vibration have minimal effects. Attenuation of ground-borne vibration might be achieved by modification at the vibration source, at the transmission path, or at the receiver side of the vibration. In this study, an investigation has been carried out to study the effect of a modification at the source by means of changing conventional railpads with softer resilient railpads. A comprehensive vibration measurement campaign was conducted before and after the installation of the softer resilient railpads. Vibration levels were measured at the free surface above the tunnel using high-accuracy seismographs that measured acceleration and velocity levels of vibration. Insertion Gains were calculated from the acquired data, and the findings demonstrated that using the soft resilient railpads decreased the vibration level on the free surface by around 10 dB for the majority of frequencies in the range of 40-200 Hz.