Influence of foundation type and soil stratification on ground vibration - a parameter study

Vibration of machinery and construction work are major sources of noise and vibration pollution in the urban environment. The frequencies dominating the vibration, and the distances over which it spreads via the ground, depend on the source. However, soil stratification and foundation type have a significant influence. Thus, in order to achieve fair accuracy in the prediction of ground vibration caused by sources vibrating on a foundation, accurate models of the ground and foundation may be required. However, for assessment of vibration in the design phase, simple models may be preferred. The paper provides a parameter study regarding the influence of soil stratification and foundation type on the ground vibration at different distances away from the source. Especially, vibration levels caused by sources placed on surface footings and piles are compared, employing a three-dimensional numerical model. Piles of different length are included in order to analyze the differences that can be expected regarding shaft-bearing and end-bearing piles. The paper provides insight into the significance of modelling the correct foundation structure and soil stratification and discusses the differences related to vibration near a source and at longer distances away from the source. Based on this, guidelines for model simplifications are given.