A Rheological Model of Sandstones considering Response to Thermal Treatment

Figure 6

Axial strain and its rate over time (temperature = 25°C, deviatoric stress = 175 MPa). is the time point of conversion from the deceleration rheological stage to stable rheological stage, is the strain at , is the time point of conversion from the stable rheological stage to acceleration rheological stage, is the strain at , is the the failure time point, and is the strain at .