Semi-analytical analysis of ground vibration generated at a railway turnout

Abstract

A railway turnout, which is a combination of a switch and a crossing is an important component in the railway network to divert trains. Due to the change in contact between the wheels and the rails as the train negotiates a turnout, severe impact loading occurs in two-directions: vertically and laterally. These cause negative environmental impacts in terms of ground vibrations. Therefore, understanding the ground response due to a railway turnout qualitatively and quantitatively is essential for soil surface in the vicinity. This thesis focuses on qualitatively and quantitatively describing the ground response through a dual load model setup through semi-analytical approach. A two-dimensional load on an Euler Bernoulli beam which is placed on a three-dimensional half-space is considered to describe the ground response. Followed by which, a load spectrum defining the interaction between the wheels and the rails is considered and the ground response is analysed. Measurements from the vicinity of a turnout is also analysed in order to compare the performance of the model to that of the real-life scenario. It is further concluded that qualitatively the ground response caused due to impact like loading that occurs at a crossing, and the presence of lateral loading is able to be explained by the model. Quantitatively, to analyse the response recommendations are to be followed to acquire the accurate load spectrum along with considering the complex track geometry for the lateral loading.