Predicting Railway-Induced Ground Vibrations

Abstract: Population growth and densification lead to growing urban environments. Unbuilt land within cities can be used to construct residences and other facilities. Population growth can further lead to a greater demand of transportation, which can require expansion of transportation systems such as railways or road traffic. Vibrations are one of the environmental problems associated with traffic in an urban environment. The vibrations can be considered a disturbance by humans and affect structures and the performance of sensitive equipment inside facilities. In this master's thesis, vibrations induced by railway traffic were studied. Railway-induced ground vibrations can be difficult to predict, since a considerable amount of mechanisms and phenomena are involved in the transmission process. Measurements of vibrations from railway traffic were performed in the city of Lund, southern Sweden, using seismometers. The seismometers were placed at different distances from the track and the passages of different trains were recorded. Analysis of the measurements were done in both time domain and frequency domain which resulted in information about vibration levels and frequency content of the vibrations for different trains and different distances from the track. Numerical simulations were carried out using the finite element method. Two-dimensional models were used to study the influence of different soil parameters and some effects of building design. Simulations that incorporated results from the measurements, by scaling the load applied in the model to the measured frequency response, were performed. The conclusions from the literature, measurements and numerical simulations were used to present some important aspects to predicting railway-induced ground vibrations.