We present the dynamic and static moduli measured in hydrostatic and triaxial load-unload processes for three sandstones with different porosities. In contrast to dynamic moduli, the statically derived ones show more sensitivity to the elevated pressure or stress. With a comparative analysis together with the modified Voigt-Reuss bounds, porosity, the rock intrinsically have, determines the variability of the static moduli, which decreases with the increasing porosity. Moreover, the static moduli are highly dependent on the stress path or history. In general, the unloading bulk modulus is almost always larger than the loading one. For Young’s modulus, the unloading modulus is much higher than the loading one at high stress, while the relation is reversed at low stress level.
Presentation Date: Monday, September 16, 2019
Session Start Time: 1:50 PM
Presentation Start Time: 3:05 PM
Presentation Type: Oral