PREDICTION OF VIBRATION TRANSMISSION FROM RAILWAYS INTO BUILDINGS USING MODELS OF INFINITE LENGTH

This paper presents a methodology for reducing to a two-dimensional procedure the three-dimensional problem of vibration transmission from railways into buildings. The dynamic-stiffness matrix method is used to obtain a three-dimensional dynamic model of a two-dimensional structure by assembling columns and beams (used to represent the walls and floors) into repeating units. Each column rests on a piled foundation whose characteristics are truly three-dimensional, so that the resulting model interfaces with three-dimensional track models. The method is extended to structures that are infinitely long thereby reducing computation times substantially and rendering the results relatively insensitive to boundary conditions and to the method used to model structural damping. A stochastic representation of the dynamic track loading can be used to specify the input to the infinite model. Both temporal and spatial random variation is included.