Investigation on Saturation State of Loess Using P-wave Velocity

Abstract

AbstractPore pressure parameter, also known as B-value, is used to characterize the saturation state of soils. Recent advances have established a relationship between B-value and P-wave velocity based on the poroelasticity theory, hence it sheds a light to evaluate the degree of saturation of soils using P-wave velocity. Previous studies in this regard often focus on granular materials, the feasibility of using the relationship for loess was less extensively studied. This paper presents experimental results on the P-wave velocity of loess using a pair of piezoceramic extender elements at a sequence of saturation states. It was found that, the P-wave velocity do not change with excitation frequency. At an excitation frequency of 5 kHz, the wave signal is most clear. Besides, the effects of initial water content and sand content on P-wave velocity were both examined. Though the P-wave velocity increases with the B-value, that is approximately in line with theoretical predictions, departures from predictions were observable at higher B-values. The outcome of this study suggests a potentially good use of P-wave velocity as an indicator of saturation in loess.KeywordsP-wave velocityB-valueSaturation