Shear Wave Velocity Measurement in the Centrifuge Using Bender Elements

摘要

Shear wave velocity is an important parameter for the design of geotechnical systems, particularly in seismically active areas. The availability of a reliable method for measuring shear wave velocity in centrifuge soil models is necessary in order to fully characterize the soil. The paper describes enhanced bender elements system developed at Rensselaer Polytechnic Institute. The fabrication process of bender elements in the laboratory is described in this paper. Also, the estimation of the shear wave velocity using the first arrival method is explained along with a study of near field presence in the results. To confirm the validity of the system, four centrifuge experiments were conducted on dry and saturated Ottawa F#55 sand. A comparison is performed between dry and saturated soil having the same relative density. Also, the effect of the direction of polarization of the shear wave is studied in the paper. The results are then compared to theoretical values estimated based on the literature and are found to match reasonably well; thus confirming the accuracy of the new system.