Volume 30, Issue 5 (September 2007)
Shear Wave Velocity of a Compacted Clayey Silt
Loess deposit covers an extensive area in the central region of Argentina. Improvement of the stress-strain behavior of loess in the field usually includes compaction. In practice, in situ shear wave velocity is suggested as an alternative to control compaction density of loess. In this work, specimens of loess were compacted in the laboratory by means of the Standard Proctor Test at different moisture contents. After compaction, the moisture content of the specimens was varied by the wetting or drying processes. Matric suction was measured. The specimens were subjected to isotropic compression tests and shear wave velocity was measured by means of bender elements. The present study allows us to evaluate the influence of density, water content, confining pressure, and the different soil structures obtained during compaction, on the measured shear wave velocity of the compacted loess. It was observed that although shear wave velocity depends on compaction density, under certain circumstances, wave velocity may be mainly controlled by soil structure and suction forces. A simple relationship was proposed to approach the observed experimental trends.