3D Fern Analysis of Ground Vibration Measures for Stationary and Moving Transit Source

Ground Vibration Measures are often employed to reduce through-soil, road or railway traffic-induced disturbances or ground vibrations caused from machine foundations. This kind of problem is sometimes a major concern in densely populated urban areas situated at soft soil conditions and for structures operating sensitive equipments. In this paper a full three-dimensional (3D) FEM investigation of the effectiveness of vertical, rectangular cross-section, wave barriers (open trenches and concrete walls) in reducing ground vibrations is carried out. The reduction capacity of these measures is also compared with an array of concrete piles or sheet piles, which replaces them. The analysis considers moving and stationary vertical load conditions simulating traffic vibrations and machine foundation vibrations respectively. Ground vibrations caused from a transient source with rather low spectrums predominant frequency, sensitive for the dynamics of the nearby buildings, is considered. A 3D FEM program is formulated employing an implicit direct time integration scheme. Radiation damping, is simulated through transmitting boundaries constructed based on the radiation criterion. Considering different parameters, numerical examples are presented which highlight the reduction capacity of the barriers