ABSTRACT
To characterize the existing environmental vibration conditions and to help predict and assess future commuter rail vibration levels along the US 36 Corridor, ground vibration measurements were carried out during freight train operations in representative areas at various distances from the existing track. The measurement results were normalized to an average train speed of 40 km/h, and the existing ground vibration levels as a function of distance from the track were generalized into curves for three geographical areas along the corridor. The results indicated that the prediction curve for locomotive-hauled trains from the U.S. Federal Transit Administration (FTA) General Vibration Assessment Method falls within the range of the generalized curves. However, the results also showed that the vibration levels measured at a site in downtown Louisville, CO were about 10 decibels (VdB) higher than at the other sites. A review of the geology along the corridor suggested that this is most likely due to the existence of abandoned coal mines that are located at depths ranging between 15 meters and 60 meters below the ground surface throughout downtown Louisville.
