Analysis of Bender Element signals during triaxial testing

Abstract

This paper presents and discusses three different wave propagation methods used to evaluate the shear wave velocities, Vs, computed from Bender Element (BE) analyses during triaxial testing. The peak-to-peak travel time, cross-correlation and phase-delay approaches were employed to calculate Vs and to determine the error in wave propagation velocities when time domain and frequency domain methods are implemented. The results obtained from vertical BE tests conducted on clay specimens indicates that, when the proper BE testing conditions are met, the differences in Vs calculated using the three methods were within ±2%. This error is small and indicates that the peak-to-peak method, the simplest and fastest time domain approach, can be employed as a straight forward method to determine shear wave velocities.