PROPAGATION OF HARMONICAL VIBRATIONS IN PEAT

Abstract

In order to check the reliability of man-made vibration prediction methods, vibration tests were
performed on one of polders in the North-West of the Netherlands. The polder was chosen because it has a rather
homogenous, thick and soft peat top layer. Here sufficient harmonical vibrations could be generated by a rather
small shaker. The shaker was designed and manufactured in order to produce harmonical vibrations at the soil
surface. It consists of two counter rotating electric vibrators (with rotating eccentric masses) in order to produce a
vertically oscillating force. For the recordings of the vibrations, six 2D or 3D geophones were placed on the soil
surface and one 2D geophone was placed on top of the shaker. The measured vibration amplitudes of the vertically
oscillating shaker were compared with 1. Two different analytical methods used for the design of vibrating
machine foundations, 2. The Confined Elasticity approach and 3. The Finite Element Method, for which Plaxis
2D software was used. Also the measured vibration amplitudes at the soil surface were compared with BarkanBornitz’s solution and Finite Element Modeling.