Numerical Simulations of Pile Integrity Tests Using a Coupled FEM SBFEM Approach



Piles are widely used to build a proper foundation for various buildings. The pile's quality in situ can be tested by a so called pile integrity test. In order to apply this test, an acceleration sensor is attached to the pile's head which than receives an impulse. Due to this impulse a p-wave runs through the pile. The major part of this wave is reflected from the pile's toe and is measured by the attached acceleration sensor on top of the pile. This yields an acceleration-time plot which has to be analysed to determine the pile's condition.

Sometimes the interpretation of these plots is difficult, specially when the cross-section of the pile is changing or is influenced by the surrounding soil. For a better understanding of this kind of measurements, numerical simulations can be performed. For these simulations a coupled finite element method (FEM) and scaled boundary finite element method (SBFEM) approach is used. This approach satisfies Sommerfeld's radiation condition and allows simulating an infinite half-space. This ensures that the applied impulse will not to be reflected at the artificial boundary which is introduced by the boundary of the numerical discretisation. The coupled approach proposed here requires discretisation of a small domain only in contrast to a purely FEM-based approach. (© 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)