Time, Temperature, and Saturation Dependence In Elasticity: The Search for Mechanism

Board Of Regents, Nshe, Obo University Of Nevada, Reno, Reno NV

Investigators

Abstract

McCall EAR-0087739 The elastic behavior of rock and other consolidated materials (e.g., concrete) is nonlinear, hysteretic, and displays log ( t ) recovery to stress and temperature perturbations. The physical mechanisms causing these unusual behaviors is not understood. It is known, however, that the primary elastic properties of a rock are a consequence of the nature of the bonds between grains, rather than of the grains themselves. The bond system within a rock is highly sensitive to changes in temperature, pore fluid configurations, and stress. The goal of this project is to develop an experimental system that will allow steady state and transient measurement of the elastic tensor of a rock sample in well-defined temperature and saturation states. The technique that will be used to determine the elastic tensor of the sample is resonant ultrasound spectroscopy (RUS). RUS has recently been shown to be an efficient and sensitive measurement technique for rock samples. Thus RUS will be used to make a careful exploration of the time, temperature, and saturation dependence of elastic behavior in rock. These data will fuel our understanding of the microscopic mechanisms driving the behavior of the bond system in rock and other consolidated materials, such as concrete.