68th Canadian Geotechnical Conference and 7th Canadian Permafrost Conference

EGT SAMPLING METHOD; TOWARD UNDISTURBED SAND SAMPLE

Session: In Situ Testing and Instrumentation I / Essais in situ et instrumentation I

Jean-François St-Laurent, WSP Canada (Canada)
Jean-Marie Konrad, Université Laval (Canada)

Numerous publications showed and described the impact of sampling technique disturbance effects over cohesionless soil samples and behavior. This paper presents a new sampling technique for fine granular soils in a saturated state, called EGT sampling technique. The EGT sampling technique stabilizes the soil by using a gelatin solution. As the gelatin solution temperature decrease, hydrogenous bridges are created between gelatin molecules to form a dissolvable elastic gel. Undrained triaxial tests were conducted to establish the viability of the technique. Obtained results suggest that the developed method maintains the soil grain to grain structure. Observed divergence between behaviors are associated to system saturation difference. In order to support and assist the EGT technique, an advanced and unified thermo fluid-mass flow numerical model, based on 11 equations was developed. The finite element model, allowed determining the stabilized soil volume under various boundaries conditions.