Small strain moduli of compacted silt by ultrasonic pulse velocity measurements

Abstract

This study reported the investigation on the small strain modulus of compacted low plastic Mississippi River Valley silt under varying moisture contents and dry densities through ultrasonic pulse velocity testing method. Detailed procedures on filtering the ultrasonic pulse velocity signals and determining the wave arrival times were established. The variation of the small strain elastic moduli with bulk density, dry density as well as water content was also studied. The elastic properties of the compacted Mississippi River Valley silt were found to remain relatively constant with increasing moisture content and bulk density up to a point then decrease rapidly as moisture content increases wet of optimum water content and bulk density increases from around 2000 kg/m3 (bilinear model). The investigation of how pulse wave velocities and moduli vary with density, moisture content, and saturation was found to provide alternative tool for assessing soil characteristics, and based on the trends observed in this study, ultrasonic pulse velocity testing could provide insight on the stability of partially saturated compacted soils.