Experimental Investigation of Elastodynamic Nonlinear Response of Dry Intact, Fractured and Saturated Rock
| العنوان: | Experimental Investigation of Elastodynamic Nonlinear Response of Dry Intact, Fractured and Saturated Rock |
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| المؤلفون: | Jacques Rivière, Prabhakaran Manogharan, Parisa Shokouhi, Chris Marone, Clay Wood, Derek Elsworth |
| المصدر: | Rock Mechanics and Rock Engineering. 55:2665-2678 |
| بيانات النشر: | Springer Science and Business Media LLC, 2021. |
| سنة النشر: | 2021 |
| مصطلحات موضوعية: | Materials science, Wave velocity, Stiffness, Geology, Mechanics, Geotechnical Engineering and Engineering Geology, Nonlinear system, Amplitude, Recovery rate, Fracture (geology), medicine, Ultrasonic sensor, medicine.symptom, Saturation (chemistry), Civil and Structural Engineering |
| الوصف: | Nonlinear elastodynamic response of fractured rocks carries crucial information on fracture features that can be exploited to forecast flow properties, friction constitutive behavior and poromechanical response. Well-controlled laboratory experiments are designed to measure the nonlinear elastodynamic response of Westerly granite in three states: dry intact, dry fractured and saturated fractured. We study the effect of fracturing and saturation in modifying the elastodynamic response of the rock. Each sample is tested at a normal stress level of 15 MPa. We measure the elastodynamic response of an intact L-shaped sample of Westerly Granite subjected to normal stress oscillations of prescribed amplitudes (0.2–1 MPa) and frequencies (0.1, 1, 10 Hz). Ultrasonic waves transmitted across the sample are used to monitor the evolution of wave velocity before, during and after dynamic stressing. The nonlinearity of the elastodynamic response is measured in terms of: (1) the offset in normalized wave velocity; (2) the amplitude of wave velocity fluctuation during the oscillations; and (3) recovery rate of the wave velocity post-oscillation. We observe that the three nonlinearity parameters show a similar trend. Irrespective of the parameter, the nonlinearity measures higher for sample in dry-intact condition than that for dry-fractured and the saturated-fractured sample exhibits smaller nonlinearity than the dry-fractured sample. As expected, the saturated sample exhibits less nonlinearity than the dry intact and fractured samples due to the presence of interstitial fluid and the resulting increased interface stiffness. Conversely, the dry intact rock shows a higher nonlinearity than the dry fractured. We use numerical simulations to show that the presence of fracture significantly alters the strain distribution across the bulk of the sample and only the contacting asperities are highly strained, thus resulting in a decrease in the measured elastodynamic nonlinearity. |
| تدمد: | 1434-453X 0723-2632 |
| URL الوصول: | https://explore.openaire.eu/search/publication?articleId=doi_________::714e07c37de354178903553d5091b006 https://doi.org/10.1007/s00603-021-02552-6 |
| حقوق: | CLOSED |
| رقم الأكسشن: | edsair.doi...........714e07c37de354178903553d5091b006 |
| قاعدة البيانات: | OpenAIRE |
Find this article in full text from Springer Verlag. | تدمد: | 1434453X 07232632 |
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