Details
| Original language | English |
|---|---|
| Title of host publication | 56th U.S. Rock Mechanics/Geomechanics Symposium |
| ISBN (electronic) | 9780979497575 |
| Publication status | Published - 2022 |
| Event | 56th U.S. Rock Mechanics/Geomechanics Symposium - Santa Fe, United States Duration: 26 Jun 2022 → 29 Jun 2022 |
Abstract
The described induced thermal stress reduction is subject of investigations in laboratory tests on hollow cylinders of natural rock salt. For this purpose, the specimen is loaded with a quasi-hydrostatic pressure (axial, circumferential and internal gas pressure) and unloaded in a pressure-controlled manner by reducing axial pressure (corresponding vertical rock pressure) at constant gas pressure in order to mechanically reproduce the expected result of thermal cooling. The unloading of the hollow cylinder by one stress component shows a so-called infiltration fracture at mechanically absolute compressive stresses in all three main stress directions due to the existing constant inner pressure and the mechanical loading situation. Four specific laboratory tests and their impact on the rock mechanical design of a gas storage cavern are discussed and compared in this paper. The measured stress differences are investigated with respect to the influences of test and specimen parameters under stress conditions during gas withdrawal in rock salt caverns. Ultrasonic measurements provide a first basis for estimating possible stress differences for these four tests. The initial pressure as well as the selected pressure reduction rates do not correlate with the level of the stress difference.
ASJC Scopus subject areas
- Earth and Planetary Sciences(all)
- Geochemistry and Petrology
- Earth and Planetary Sciences(all)
- Geophysics
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56th U.S. Rock Mechanics/Geomechanics Symposium. 2022.
Research output: Chapter in book/report/conference proceeding › Conference contribution › Research › peer review
}
TY - GEN
T1 - Special triaxial experiments on the fracture behavior of hollow rock salt specimens
AU - Baumgärtel, L.
AU - Körner, F.
AU - Leuger, B.
N1 - Publisher Copyright: © 2022 ARMA, American Rock Mechanics Association.
PY - 2022
Y1 - 2022
N2 - The knowledge of possible fracture formation and propagation in rock salt caverns is an important aspect for their safety-oriented design. During gas withdrawal the internal pressure is reduced and the associated cooling of the gas and thus also of the cavern wall cause a reduction of the principal stresses and can possibly lead to finite fractures at the cavern wall, if the minimal stress component falls below the present gas pressure by a certain stress difference.The described induced thermal stress reduction is subject of investigations in laboratory tests on hollow cylinders of natural rock salt. For this purpose, the specimen is loaded with a quasi-hydrostatic pressure (axial, circumferential and internal gas pressure) and unloaded in a pressure-controlled manner by reducing axial pressure (corresponding vertical rock pressure) at constant gas pressure in order to mechanically reproduce the expected result of thermal cooling. The unloading of the hollow cylinder by one stress component shows a so-called infiltration fracture at mechanically absolute compressive stresses in all three main stress directions due to the existing constant inner pressure and the mechanical loading situation. Four specific laboratory tests and their impact on the rock mechanical design of a gas storage cavern are discussed and compared in this paper. The measured stress differences are investigated with respect to the influences of test and specimen parameters under stress conditions during gas withdrawal in rock salt caverns. Ultrasonic measurements provide a first basis for estimating possible stress differences for these four tests. The initial pressure as well as the selected pressure reduction rates do not correlate with the level of the stress difference.
AB - The knowledge of possible fracture formation and propagation in rock salt caverns is an important aspect for their safety-oriented design. During gas withdrawal the internal pressure is reduced and the associated cooling of the gas and thus also of the cavern wall cause a reduction of the principal stresses and can possibly lead to finite fractures at the cavern wall, if the minimal stress component falls below the present gas pressure by a certain stress difference.The described induced thermal stress reduction is subject of investigations in laboratory tests on hollow cylinders of natural rock salt. For this purpose, the specimen is loaded with a quasi-hydrostatic pressure (axial, circumferential and internal gas pressure) and unloaded in a pressure-controlled manner by reducing axial pressure (corresponding vertical rock pressure) at constant gas pressure in order to mechanically reproduce the expected result of thermal cooling. The unloading of the hollow cylinder by one stress component shows a so-called infiltration fracture at mechanically absolute compressive stresses in all three main stress directions due to the existing constant inner pressure and the mechanical loading situation. Four specific laboratory tests and their impact on the rock mechanical design of a gas storage cavern are discussed and compared in this paper. The measured stress differences are investigated with respect to the influences of test and specimen parameters under stress conditions during gas withdrawal in rock salt caverns. Ultrasonic measurements provide a first basis for estimating possible stress differences for these four tests. The initial pressure as well as the selected pressure reduction rates do not correlate with the level of the stress difference.
UR - http://www.scopus.com/inward/record.url?scp=85149235550&partnerID=8YFLogxK
U2 - 10.56952/arma-2022-0095
DO - 10.56952/arma-2022-0095
M3 - Conference contribution
BT - 56th U.S. Rock Mechanics/Geomechanics Symposium
T2 - 56th U.S. Rock Mechanics/Geomechanics Symposium
Y2 - 26 June 2022 through 29 June 2022
ER -