Automatic Shear Wave Velocity Estimation in Bender Element Testing

Dynamic properties of soils, such as shear wave velocity and damping, are some of critical parameters in the design of civil infrastructures subjected to vibrations from earthquakes and machine foundations. Bender element (BE) testing is used in the laboratory to determine shear wave velocity; however, there is no standard procedure for the interpretation of the results. The main limitation in BE testing is the correct estimation of the shear wave arrival time leading to uncertainty in the values of shear wave velocity. In this paper, three different automatic methods for the shear wave arrival time detection were tested. From these methods, a new procedure was proposed for the automatic determination of the shear wave arrival time using the Akaike information criterion. The method is tested on a series of bender element measurements giving less than 5 % error when the results were compared with the standard method for a signal-to-noise ratio higher than four.