JOURNAL OF ROCK MECHANICS

JOURNAL OF ROCK MECHANICS

Development of a concentric-membrane cell for true triaxial stress testing of cylindrical rock samples

Document Type : ٍAn English Original Article

Authors
Hamedan University of Technology
Abstract
Rocks in nature are typically subjected to triaxial compressive stresses, clearly underscoring the importance of reliably measuring their true triaxial strength. However, true triaxial loading testing of rocks, mainly performed on cubic samples, still faces many challenges, such as an intricate sample preparation process and costly setup. This study presents a cell designed to apply true triaxial loads to rock cores using the conventional compression testing apparatus. The use of cylindrical specimens simplifies sample preparation, ensures compatibility with existing core drilling methods, and allows for more efficient replication of in-situ stress conditions in rock formations while avoiding stress concentration issues commonly observed at the corners of cubic specimens. The design of the cell is based on two concentric membranes. The annulus space between the membranes is divided into four 90-degree sectors, three of which are filled with steel plates, while the fourth is filled with hydraulic fluid. Each principal radial stress is provided by a separate hydraulic pump, and the axial stress is applied by a hydraulic jack. This study reports the results of 15 true triaxial tests on similar concrete samples using the innovative cell and under different stress fields.
Keywords
Subjects

[1]    F. Deák, P. Ván, B. Vásárhelyi, Hundred years after the first triaxial test, Periodica Polytechnica Civil Engineering. 56 (2012) 115–122. https://doi.org/10.3311/pp.ci.2012-1.13.
[2]    T. V Karman, Festigkeitsversuche unter allseitigem Drunk, Z. Ver. Deu. Ing. 55 (1911) 1749.
[3]    T. Esaki, T. Kimura, Mechanical Behavior Of Rocks Under Generalized High Stress Conditions, ISRM International Symposium. (1989) 8.
[4]    R. Boker, Die Mechanik der bleibenden Formanderung in kristallinisch aufgebauten Korpern, Ver. Dt. Ing. Mitt. Forsch. 175 (1915) 1–51.
[5]    S.A.F. Murrell, The Effect of Triaxial Stress Systems on the Strength of Rocks at Atmospheric Temperatures, Geophysical Journal of the Royal Astronomical Society. 10 (1965) 231–281. https://doi.org/10.1111/j.1365-246X.1965.tb03155.x.
[6]    J. Handin, H.C. Heard, J.N. Magouirk, Effects of the intermediate principal stress on the failure of limestone, dolomite, and glass at different temperatures and strain rates, Journal of Geophysical Research. 72 (1967) 611–640. https://doi.org/10.1029/JZ072i002p00611.
[7]    M. Kwasniewski, X. Li, M. Takahashi, True triaxial testing of rocks, CRC Press, 2012.
[8]    M. Takahashi, T. Narita, Y. Tomishima, R. Arai, Various loading systems for rock true triaxial compression test, Journal of the Japan Society of Engineering Geology. 42 (2001) 242–247.
[9]    K. Mogi, Experimental rock mechanics, CRC Press, 2006.
[10]  E.C. Robertson, Experimental study of the strength of rocks, Geological Society of America Bulletin. 66 (1955) 1275–1314.
[11]  E.R. Hoskins, The failure of thick-walled hollow cylinders of isotropic rock, International Journal of Rock Mechanics and Mining Sciences & Geomechanics Abstracts. 6 (1969) 99–125. https://doi.org/10.1016/0148-9062(69)90030-8.
[12]  R. Ulusay, International Society for Rock Mechanics., The ISRM suggested methods for rock characterization, testing and monitoring : 2007-2014, 2015.
[13]  H. Weigler, G. Becker, Untersuchungen uber das Bruch-und Verformungsverhalten von beton bei Zweiachsiger Beanspruchung, Ernst, 1963.
[14]  H. Weigler, G. Becker, Über das Bruch-und Verformungsverhalten von Beton bei mehrachsiger Beanspruchung, Der Bauingeneieur. 36 (1961) 390–396.
[15]  M. Furuzumi, F. Sugimoto, Effect of Intermediate Principal Stress on Failure of Rocks and Failure Condition of Rocks under Multiaxial Stresses, Journal of the Japan Society of Engineering Geology. 27 (1986) 13–20.
[16]  M.S. King, N.A. Chaudhry, A. Shakeel, Experimental ultrasonic velocities and permeability for sandstones with aligned cracks, International Journal of Rock Mechanics and Mining Sciences And. 32 (1995) 155–163. https://doi.org/10.1016/0148-9062(94)00033-Y.
[17]  J.P.M. Hojem, The design and construction of a tiaxial and polyaxial cell fortesting rock materials, S. Afr Mech. Engr. 18 (1968) 57–61.
[18]  B.G.D. Smart, A true triaxial cell for testing cylindrical rock specimens, in: International Journal of Rock Mechanics and Mining Sciences and Geomechanics Abstracts, 1996: p. 67A.
[19]  J.A. Franklin, E. Hoeck, Developments in triaxial testing technique, Rock Mechanics Felsmechanik Mécanique Des Roches. 2 (1970) 223–228. https://doi.org/10.1007/BF01245576.
[20]  X. Li, L. Shi, B. Bai, Q. Li, D. Xu, X. Feng, True-triaxial testing techniques for rocks—state of the art and future perspectives, True Triaxial Testing of Rocks. (2012) 3–18. https://doi.org/10.1201/b12705.
[21]  G. Herget, K. Unrug, In situ rock strength from triaxial testing, International Journal of Rock Mechanics and Mining Sciences And. 13 (1976) 299–302. https://doi.org/10.1016/0148-9062(76)91828-3.
[22]  M.I. Alsayed, Utilising the Hoek triaxial cell for multiaxial testing of hollow rock cylinders, International Journal of Rock Mechanics and Mining Sciences. 39 (2002) 355–366. https://doi.org/10.1016/S1365-1609(02)00030-8.
[23]  K. Mogi, Effect of the Intermediate Principal Stress on Rock Failure, Journal of Geophysical Research. 72 (1967) 5117–5131.
[24]  K. Tani, T. Nozaki, S. Kaneko, Y. Toyo-oka, H. Tachikawa, Down-hole triaxial test to measure average stress-strain relationship of rock mass, Soils and Foundations. 43 (2003) 53–62.
[25]  A. Taheri, K. Tani, Development of an apparatus for down-hole triaxial tests in a rock mass, International Journal of Rock Mechanics and Mining Sciences. 45 (2008) 800–806. https://doi.org/10.1016/j.ijrmms.2007.09.005.
[26]  A. Taheri, K. Tani, In-Situ Triaxial Test Method For Rock Masses–Apparatus Description And Testing Procedure, in: Geotechnical Engineering For Disaster Mitigation And Rehabilitation And Highway Engineering 2011: Geotechnical and Highway Engineering—Practical Applications, Challenges and Opportunities (With CD-ROM), World Scientific, 2011: pp. 475–480.
[27]  G. Barla, M. Barla, D. Debernardi, New triaxial apparatus for rocks, Rock Mechanics and Rock Engineering. 43 (2010) 225–230. https://doi.org/10.1007/s00603-009-0076-7.
[28]  K. Suzuki, Study of the failure and deformability of jointed rock masses using large rock block specimens, True Triaxial Testing of Rocks. 4 (2012) 61.
[29]  A.K. Schwarzkopff, S. Priest, N. Melkoumian, J.A. Egudo, Design and fabrication of a low cost true triaxial cell for testing multiple size specimens, 2013.
[30]  A.K. Schwartzkopff, N.S. Melkoumian, S.D. Woithe, Design Improvements for a True Triaxial Cell to Monitor Initiation and Propagation of Damage and Body Cracks during Testing BT - Mine Planning and Equipment Selection, in: C. Drebenstedt, R. Singhal (Eds.), Springer International Publishing, Cham, 2014: pp. 551–560.
[31] H. Atapour, A. Mortazavi, Performance Evaluation of Newly Developed True Triaxial Stress Loading and Pore Pressure Applying System to Simulate the Reservoir Depletion and Injection. Geotechnical Testing Journal 43 (2020): 701–719.
[32]  A.M. Al-Ajmi, R.W. Zimmerman, Relation between the Mogi and the Coulomb Failure Criteria. International Journal of Rock Mechanics and Mining Sciences 42 (2005): 431–39.
[33]  K. Mogi, Fracture and Flow of Rocks under High Triaxial Compression. Journal of Geophysical Research 76 (1971): 1255–69.