Elastic waves in salt-cemented granular soils

Naturally cemented phenomenon may have an effect to the mechanical behavior of soils. Dissolved salt, one of the most common soluble materials in geotechnical engineering soils, can create a cementation condition due to drying process of soil media. This study concentrates in investigating the characteristics of elastic waves in granular soils cemented by dissolved salt. Specimens, that were preparing using three different sizes of glass beads, 0.26, 0.5 and 1.29 mm in median diameter mixing with salt water having various concentrations of 0, 0.1, 0.2, 0.5, 1.0, and 2.0 M NaCl, are used. The elastic waves including P-and S-waves, generated by bender elements and piezo disk elements, were applied to explore the specimens. The evolution of P-wave and S-wave velocities during drying process show three stages according to the degree of saturation: 1) S-wave velocities increase and P-wave velocities reduce when the degree of saturation reduces from 100% to 90%; 2) P-& S-wave velocities have a minor change with degree of saturation of 90%-10%; 3) The velocities increase significantly when the specimens are with degree of saturation of 10%-0%. The resonant frequencies of S-waves show a similar trend as the S-wave velocities. This study describes the meaningful trends of elastic waves in geo-materials cemented by dissolved salt.