Effects of the canyon topography on railway environment vibrations

The train-induced vibrations that permeate railway environments are becoming more prominent with the rapid development of China's high-speed railway network. Because canyons are quite common in nature, it is inevitable that newly constructed railways will pass through these areas. Therefore, it is necessary to study the influences of canyons on the propagation of vibration waves. In this paper, a two-dimensional finite-element calculation model of the subgrade-canyon topography under the action of trains is established and the influences of the canyon width and shape in addition to the properties of the foundation soil within the canyon are studied. The results show that vibrations are amplified near the foot of the canyon. The canyon significantly reduces the ground vibration accelerations in both the vertical and the horizontal directions. Moreover, a wider canyon corresponds to a greater decrease in the acceleration at the centre of the canyon and a reduction in all vertical and horizontal vibration displacements. Furthermore, as the foundation soil hardens, the decreases in the accelerations in both the vertical and the horizontal directions are significantly reduced.