Analysis of Vibrations and Infrastructure Deterioration Caused by High-Speed Rail Transit

The effects of a heavy travelling load on the soil medium and on the adjacent structures were studied. Five soil profiles were analyzed, three from sites in Southern California and two from well documented sites in Europe. It was found that the material damping in the soil layers does not affect attenuation, but rather radiation damping is the most significant. Four of the Five soil profiles studied showed a decay of vibration of 20dB within a distance of 10 meters. Only the Swedish soil profile at Ledsgard showed a long-distance propagation tendency; that peculiar site has a soft marine layer between two stiff layers and the vibrational energy was retained near the surface. Flexible foundation soil-structure interaction analyses were performed and found that the damping values used for the building vibration modes to be the key factor. Some ground vibration amplitudes were diminished by the kinematic interaction with the rigid footings and by the large inertia of the building. vibrations, however, can be amplified by resonance within the structure.