Abstract
The long-term behavior of rock mass plays a vital role in the overall stability of underground structures. One possible long-term scenario is the degradation of the rock mass, especially in unstable clay-bearing rocks susceptible to water ingress. Lack of efficient countermeasures in extreme cases could significantly affect the physical and mechanical properties of rocks and alter the engineering behavior to some extent. In this research, we describe the case of the Golab access tunnel where it is subject to failure in a specific section containing meta-shales. The situation was considered to have occurred as a consequence of long-term deteriorating phenomenon after a 5-year period. To characterize the rock mass, point load tests were conducted on the rock samples in failure zones and values were compared with the ones obtained through primary geotechnical studies. Slake durability index (SDI) was also used to assess the vulnerability of rocks to changes in moisture content and was correlated to point load values. Additionally, GSI was measured in the failed regions, and the decreasing trend was presented in accordance with time. By taking advantage of the engineering characteristics, ground reaction curves in short-term and long-term conditions were obtained. It was deduced that the temporary support system applied to the tunnel in this section cannot provide a safe margin against long-term strains imposed by the ground. Therefore, another support system was suggested and applied to the unstable sections of tunnel to prevent further hazards.
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References
Azimian A, Ajalloeian R (2015) Empirical correlation of physical and mechanical properties of marly rocks with P wave velocity. Arab J Geosci 8:2069–2079. https://doi.org/10.1007/s12517-013-1235-4
Bryson LS, Gomez-Gutierrez IC, Hopkins TC (2012) Development of a new durability index for compacted shale. Eng Geol 139–140:66–75. https://doi.org/10.1016/j.enggeo.2012.04.011
Cai M, Kaiser PK, Uno H, Tasaka Y, Minami M (2004) Estimation of rock mass deformation modulus and strength of jointed hard rock masses using the GSI system. Int J Rock Mech Min Sci 41:3–19. https://doi.org/10.1016/S1365-1609(03)00025-X
Carranza-Torres C, (2004) Elasto-plastic solution of tunnel problems using the generalized form of the hoek-brown failure criterion. International Journal of Rock Mechanics and Mining Sciences 41:629–639.
Chugh YP, Missavage RA (1981) Effects of moisture on strata control in coal mines. Eng Geol 17:241–255. https://doi.org/10.1016/0013-7952(81)90001-6
Deo P (1972) Shales as embankment materials. Purdue University, West Lafayette
Doostmohammadi R, Moosavi M, Mutschler T, Osan C (2008) Influence of cyclic wetting and drying on swelling behavior of mudstone in south west of Iran. Environ Geol 58:999. https://doi.org/10.1007/s00254-008-1579-3
Franklin JA, Chandra A (1972) The slake-durability test international. Journal of Rock Mechanics and Mining Sciences 9:325–341
Fuenkajorn K (2011) Experimental assessment of long-term durability of some weak rocks. Bull Eng Geol Environ 70:203–211. https://doi.org/10.1007/s10064-010-0297-8
Gamble JC (1971) Durability-plasticity classification of shales and other argillaceous rocks. University of Illinois at Urbana-Champaign, Champaign County
Gökceoğlu C, Ulusay R, Sönmez H (2000) Factors affecting the durability of selected weak and clay-bearing rocks from Turkey, with particular emphasis on the influence of the number of drying and wetting cycles. Eng Geol 57:215–237. https://doi.org/10.1016/S0013-7952(00)00031-4
González de Vallejo LI (2003) SRC rock mass classification of tunnels under high tectonic stress excavated in weak rocks. Eng Geol 69:273–285. https://doi.org/10.1016/S0013-7952(02)00286-7
González de Vallejo LI, Ferrer M (2011) Geological engineering vol 1. CRC Press, Boca Raton
Heidari M, Rafiei B, Mohebbi Y, Torabi-Kaveh M (2015) Assessing the behavior of clay-bearing rocks using static and dynamic slaking indices. Geotech Geol Eng 33:1017–1030. https://doi.org/10.1007/s10706-015-9884-6
Hoek E, Guevara R (2009) Overcoming squeezing in the Yacambú-Quibor tunnel. Venezuela Rock Mechanics and Rock Engineering 42:389–418. https://doi.org/10.1007/s00603-009-0175-5
Hopkins T, Deen R (1984) Identification of Shales
Inc R (2009) RocSupport tutorial manual. Rocscience Inc., Toronto
Itasca Consulting Group Inc (2011) FLAC-fast Lagrangian analysis of continua, 7.0 edn. Itasca Consulting Group Inc., Minneapolis
Jethwa JL (1981) Evaluation of rock pressure under squeezing rock conditions for tunnels in Himalayas. University of Roorkee, Roorkee
Kaiser PK, Morgenstern NR (1982) Time-independent and time-dependent deformation of small tunnels—III pre-failure behaviour. International Journal of Rock Mechanics and Mining Sciences & Geomechanics Abstracts 19:307–324. https://doi.org/10.1016/0148-9062(82)91366-3
Koncagül EC, Santi PM (1999) Predicting the unconfined compressive strength of the Breathitt shale using slake durability, shore hardness and rock structural properties. Int J Rock Mech Min Sci 36:139–153. https://doi.org/10.1016/S0148-9062(98)00174-0
Lunardi P (2008) Design and Construction of Tunnels: Analysis of Controlled Deformations in Rock and Soils (ADECO-RS). Springer-Verlag Berlin Heidelberg. doi:https://doi.org/10.1007/978-3-540-73875-6
Marinos V, Marinos P, Hoek E (2005) The geological strength index: applications and limitations. Bull Eng Geol Environ 64:55–65. https://doi.org/10.1007/s10064-004-0270-5
Mitra S (1991) Studies on long-term behaviour of underground powerhouse cavities in soft rocks. University of Roorkee, Roorkee
Moradian ZA, Ghazvinian AH, Ahmadi M, Behnia M (2010) Predicting slake durability index of soft sandstone using indirect tests. Int J Rock Mech Min Sci 47:666–671. https://doi.org/10.1016/j.ijrmms.2010.02.001
Peng S, Zhang J (2007) Engineering geology for underground rocks, 1st edn. Springer-Verlag, Berlin Heidelberg
Sandrone F (2008) Analysis of pathologies and long term behaviour of the Swiss national road tunnels. Ph.D. Thesis, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
Santi PM (2006) Field methods for characterizing weak rock for engineering. Environmental & Engineering Geoscience 12:1–11
Singh B, Goel RK (1999) Chapter-8 - Rock mass quality (Q) — System. In: Rock Mass Classification. Elsevier Science Ltd, Oxford, pp 62–91. doi: https://doi.org/10.1016/B978-008043013-3/50008-0
Singh B, Jethwa JL, Dube AK, Singh B (1992) Correlation between observed support pressure and rock mass quality. Tunn Undergr Space Technol 7:59–74. https://doi.org/10.1016/0886-7798(92)90114-W
Wittke W, Erichsen C (2000) Stability Analysis for Tunnels: Fundamentals. Verlag Glückauf
Wood LE, Deo P (1975) A suggested system for classifying shale materials for embankments. Bull Assoc Eng Geol 12:39–55
Xue Y, Mishra B, Gao D (2017) Using the relaxation test to study variation in the time-dependent property of rock and the consequent effect on time-dependent roof failure. Rock Mech Rock Eng. https://doi.org/10.1007/s00603-017-1232-0
Yagiz S (2011) Correlation between slake durability and rock properties for some carbonate rocks. Bull Eng Geol Environ 70:377–383. https://doi.org/10.1007/s10064-010-0317-8
Acknowledgments
The authors wish to sincerely appreciate the assistance of Mr. Esmaeil Baradaran, the head of Golab water conveyance project supervising division in Rayab Consulting Engineers for valuable discussions about the work. The authors would also like to thank Mr. Abbas Eftekhari of the Imensazan Consulting Engineers (ICE) for providing the tunnel geological profile and conducting the Point Load tests.
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Narimani Dehnavi, R., Sadeghi, M. Deterioration of weak rocks over time and its effect on designing tunnel support systems. Bull Eng Geol Environ 78, 1045–1056 (2019). https://doi.org/10.1007/s10064-017-1154-9
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DOI: https://doi.org/10.1007/s10064-017-1154-9