THE NUMERICAL PREDICTION OF RAILWAY INDUCED VIBRATIONS IN AN URBAN ENVIRONMENT

Abstract. Boundary element methods are often employed in the numerical prediction of rail-way induced vibrations. The evaluation of large models is limited, however, due to the compu-tational requirements in terms of memory storage and computation time, which impedes to ri-gorously account for the presence of multiple buildings in an urban area. This paper presents a novel hierarchical boundary element method for elastodynamics based on halfspace Green’s functions; meshing of the free surface and the layer interfaces is hence avoided. Numerical examples are discussed to demonstrate the effectiveness of the methodology, indicating that the model size can be increased with an order of magnitude, which allows to perform large scale boundary element computations. A synthetic case study of an urban environment is finally introduced to investigate the influence of the trough–soil coupling of closely spaced buildings on the wavefield in the soil and the structural response