Abstract：Piezoelectric sensors used in geotechnical engineering have advantages in measuring elastic wave velocity of soil under gravity, however the measurement of elastic wave velocity of soil under hypergravity condition in centrifuge model test is still very challenging.In this study, high-performance mini-type piezoelectric bender elements and bending disks are designed.Measurement method for elastic wave velocities in centrifuge model tests is proposed, in which many methods are used, such as electro-magnetic coating, water proofing and grounding, fast staking and band-path filtering of received signal, and time-domain first-arrival method for travel time identification.A centrifuge model test of level loess ground under 60g was carried out to reproduce the soil softening process induced by rainfall infiltration, in which the shear wave velocity and compressive wave velocity were monitored simutaneously.By combing the estimation of soil density from TDR measurement, the variation of shear modulus, Young's modulus and Poisson's ratio of the soil in the model were estimated according to the elastic theory.The proposed techniques enable the real-time measurement and characterization of elastic parameters of soils in centrifuge model tests under hypergravity environment.
