One of the aims of the European research project FINE-2 is to contribute to reducing noise and vibrations caused by railway traffic. In this context, the development of models describing the influence of relevant parameters on the excitation of train-induced vibration emissions were investigated in WP 8 "Ground Vibration" which is led by DB Systemtechnik. Here, resilient track components and especially under-sleeper pads were considered by a new modelling approach. Dependent on the dynamic stiffness of the relevant superstructure components, the model is based on the German standard DIN 45673-4, which describes an approach to compute the insertion loss of under-ballast mats by using an impedance model. The paper will show a general description of the model, the steps taken to adapt the existing model to consider under-sleeper pads instead of under-ballast mats, as well as results validated by using existing measurements.