A pilot study of in-hole type CPTu using piezoelectric bender elements

Abstract

In-hole type CPTu equipment which combines the concepts of in-hole test method and piezocone test method was newly developed in order to evaluate the dynamic properties of marine soils. The objective of this paper is to investigate the practical application of in-hole type CPTu. Laboratory tests using kaolinite as soft soil and numerical simulations using finite element method were carried out in this study. The shear wave velocities of kaolinite were measured with time, and the effects of soil disturbance due to the installation of source and receiver were also examined for various distances between source and receiver. It was found that it is necessary to maintain the length of swing arm as well as the distance between source and receiver consistently to obtain the rigorous test results. The laboratory test and numerical re-sults also reveal that the disturbance due to the installation of swing arm apparently affect the shear wave velocity.