The effect of temperature and pH on the strength anisotropy of schists

Yıl 2023, Cilt: 12 Sayı: 4, 1318 - 1324, 15.10.2023

Mehmet Özdemir , Sunay Beyhan , Kaan Erarslan

https://doi.org/10.28948/ngumuh.1308451

Öz

Rock strength is an important parameter in mining project processes. The distribution of strength values is important in rocks showing different strength properties according to orientations in terms of strength anisotropy, such as sedimentary and metamorphic rocks. The studies can be carried out at different temperatures and pHs. Strength values may change in summer, winter, acidic and basic conditions. In this study, schist samples were taken from the copper mine in the Hanönü district of Kastamonu, Türkiye. Besides the strength anisotropy of metamorphic rocks such as green schist and mica schist, the variation of strength values at different temperatures (5°C and 35°C) and pH (2, 7 and 12) was investigated. In general, minimum strengths at 15°-45° and maximum results between 60°-90° degrees were obtained for both rocks. Generally, both rocks showed maximum strength distribution at 5°C. Maximum strength was obtained at pH12 for mica schist, close distribution at other pH values, and similar distribution at all pH values for green schist. The degree, temperature, and pH parameters affected the strength of mica schist, while the degree and temperature parameters were effective in the strength of green schist. Examination of the effect of the change of different parameters on the strength of the rocks will contribute to the project and operation processes.

Anahtar Kelimeler

Anisotropy, Mica Schist, pH, Temperature, Green Schist

Şistlerin dayanım anizotropisinde sıcaklık ve pH’ın etkisi

Öz

Madencilik çalışmaları proje süreçlerinde kayaç dayanımı önemli bir parametredir. Sedimanter ve metamorfik kayaçlar gibi dayanım anizotropisi açısından yönelimlere göre farklı dayanım özellikleri gösteren kayaçlarda dayanım değerleri dağılımı önem arz etmektedir. Bunun birlikte farklı sıcaklıklarda ve pH’larda çalışmalar yapılabilmektedir. Yaz, kış, asidik ve bazik ortamlarda dayanım değerleri değişebilmektedir. Bu çalışmada Türkiye Kastamonu ili Hanönü ilçesindeki bakır madeninden şist numuneleri alınmıştır. Yeşil şist ve mika şist gibi metamorfik kayaçların dayanım anizotropisinin yanında farklı sıcaklık (5°C ve 35°C) ve pH’larda (2, 7 ve 12) dayanım değerlerinin değişimi incelenmiştir. Genel olarak her iki kayaç için 15°-45° derecelerde minimum dayanımlar, 60°-90° dereceler arasında ise maksimum sonuçlar elde edilmiştir. Genellikle her iki kayaç 5°C’de maksimum dayanım dağılımı göstermiştir. Mika şist için pH parametresinde maksimum dayanım pH12’de, diğer pH’larda yakın dağılım, yeşil şist için ise tüm pH değerlerinde benzer dağılım elde edilmiştir. Mika şist için derece, sıcaklık ve pH parametreleri, yeşil şist için ise derece ve sıcaklık parametreleri dayanımda etkili olmuştur. Kayaçlarda farklı parametrelerin değişiminin dayanıma etkisinin incelenmesi proje ve işletme süreçlerinde katkı sağlayacaktır.

Anahtar Kelimeler

Anisotropy, Mika Şist, pH, Sıcaklık, Yeşil Şist

Kaynakça

• K. Ullemeyer, S. Siegesmund, P. N. J. Rasolofosaon and J. H. Behrmann, Experimental and texture-derived P-wave anisotropy of principal rocks from the TRANSALP traverse: An aid for the interpretation of seismic field data, Tectonophysics, 414 (1–4), 97–116, 2006. https://doi.org/10.1016/j.tecto.2005.10.024.
• R. Ajalloeian and G. R. Lashkaripour, Strength anisotropies in mudrocks. Bulletin of Engineering Geology and the Environment, 59 (3), 195–199, 2000. https://doi.org/10.1007/s100640000055.
• T. Ramamurthy, G. V. Rao and J. Singh, Engineering behaviour of phyllites, Engineering Geology, 33 (3), 209–225. 1993. https://doi.org/10.1016/0013-7952(93)90059-L.
• A. Ghazvinian, R. Geranmayeh Vaneghi and M. R. Hadei, Behavior and failure mechanism of angoran schists under uniaxial compression loading. ISRM Int. Symp. EUROCK 2012, 28-30 May 2012, pp. 1–10, Stockholm, Sweden, 2012.
• J. W. Cho, H. Kim, S. Jeon, and K. B. Min, Deformation and strength anisotropy of Asan gneiss, Boryeong shale, and Yeoncheon schist, International Journal of Rock Mechanics and Mining Sciences, 50, 158–169. 2012. https://doi.org/10.1016/ j.ijrmms.2011.12.004.
• H. Saroglou and G. Tsiambaos, A modified Hoek–Brown failure criterion for anisotropic intact rock. International Journal of Rock Mechanics and Mining Sciences, 45 (2), 223–234. 2008. https://doi.org/10.1016/j.ijrmms.2007.05.004.
• M. H. B. Nasseri, K. S. Rao and T. Ramamurthy, Anisotropic strength and deformational behaviour of Himalayan schists, International Journal of Rock Mechanics and Mining Sciences, 40 (1), 3–23, 2003. https://doi.org/10.1016/S1365-1609(02)00103-X.
• X. P. Zhang, L. N. Y. Wong, S. J. Wang and G. Y. Han, Engineering properties of quartz mica schist, Engineering Geology, 121 (3–4), 135–149, 2011. https://doi.org/10.1016/j.enggeo.2011.04.020.
• H. Song, Y. Jiang, D. Elsworth, Y. Zhao, J. Wang and B. Liu, Scale effects and strength anisotropy in coal, International Journal of Coal Geology, 195 (March), 37–46, 2018. https://doi.org/10.1016/ j.coal.2018.05.006.
• Y. Togashi, M. Kikumoto, K. Tani, K. Hosoda and K. Ogawa, Detection of deformation anisotropy of tuff by a single triaxial test on a single specimen, International Journal of Rock Mechanics and Mining Sciences, 108 (November 2017), 23–36, 2018. https://doi.org/10.1016/j.ijrmms.2018.04.054.
• S. Li, R. Huo, F. Yoshiaki, D. Ren and Z. Song, Effect of acid-temperature-pressure on the damage characteristics of sandstone, International Journal of Rock Mechanics and Mining Sciences, 122, 104079, 2019. https://doi.org/10.1016/j.ijrmms.2019.104079.
• G. Zhao, Y. Hu and P. Jin, Exploratory Experimental Study on the Mechanical Properties of Granite Subjected to Cyclic Temperature and Uniaxial Stress, Energies, 13 (8), 1–17, 2020. https://doi.org/10.3390/ en13082061.
• C. Li, Y. Hu, T. Meng, P. Jin, Z. Zhao and C. Zhang, Experimental study of the influence of temperature and cooling method on mechanical properties of granite: Implication for geothermal mining, Energy Science and Engineering, 8(5), 1716–1728, 2020. https://doi.org/10.1002/ese3.627.
• Y. Hu, Y. Hu, G. Zhao, P. Jin, Z. Zhao and C. Li, Experimental Investigation of the Relationships Among P-Wave Velocity, Tensile Strength, and Mode-I Fracture Toughness of Granite After High-Temperature Treatment, Natural Resources Research, 31(2), 801–816, 2022. https://doi.org/10.1007/s11053-022-10020-3.
• H. Wang, Y. Wang and X. Fu, Experimental study on coupling influence of temperature and confining pressure to deformation and strength characteristics of rock-like material with pre-existing crack, Materials, 14 (24), 1–15, 2021. https://doi.org/10.3390/ ma14247572.
• J. Pan, Z. Feng, Y. Zhang, X. Xi, S. Miao and M. Cai, Experimental study on evaluation of porosity, thermal conductivity, UCS, and elastic modulus of granite after thermal and chemical treatments by using P-wave velocity, Geoenergy Science and Engineering, 230, 212184, 2023. https://doi.org/10.1016/ j.geoen.2023.212184.
• J. Zhang, Y. Shen, G. Yang, H. Zhang, Y. Wang, X. Hou, Q. Sun and G. Li, Inconsistency of changes in uniaxial compressive strength and P-wave velocity of sandstone after temperature treatments, Journal of Rock Mechanics and Geotechnical Engineering, 13, 143-153, 2021. https://doi.org/10.1016/ j.jrmge.2020.05.008.
• V. Vishal, S. P. Pradhan and T. N. Singh, Tensile Strength of Rock Under Elevated Temperatures, Geotechnical and Geological Engineering, 29 (6), 1127–1133, 2011. https://doi.org/10.1007/s10706-011-9440-y.
• W. Hongwei, G. Qiang, C. Lizhuang, W. Yongyan and L. Jianguang, Investigation of the Effect of Fissure Angle and Temperature on the Strength and Deformation of Rock-like Material. IOP Conf. Ser. Mater. Sci. Eng., pp. 1–7, 2020.
• A. Moslehy, K. A. Alshibli and T. J. Truster, Influence of Temperature and Crystal Orientation on Compressive Strength of Rock Salt Using a Newly Developed High-Pressure Thermal Cell, Rock Mechanics and Rock Engineering, 55 (1), 91–108, 2022. https://doi.org/10.1007/s00603-021-02655-0.
• Y. Liu, W. Liu and C. Wang, Study on mechanical properties and constitutive model of rock-like materials under acid corrosion, Authorea, 13 (March), 1–11, 2023.https://doi.org/10.22541/au.167845653.36883128/v1.
• B. Guo, T. Cheng, J. Sun, S. Tian, Y. Chen and Y. Niu, Evolution of Peak Shear Strength of Rock Fractures Under Conditions of Repetitive Dry and Wet Cycling, Frontiers in Earth Science, 10 (July), 1–17, 2022. https://doi.org/10.3389/feart.2022.848440.
• T. N. Singh, P. K. Sharma and M. Khandelwal, Effect of pH on the physico-mechanical properties of marble, Bulletin of Engineering Geology and the Environment, 66 (1), 81–87, 2007. https://doi.org/10.1007/s10064-006-0047-0.
• T. P. Ngo, Q. B. Bui, V. T. A. Phan and H. B. Tran, Durability of geopolymer stabilised compacted earth exposed to wetting–drying cycles at different conditions of pH and salt, 329, 127168, 2022. https://doi.org/10.1016/j.conbuildmat.2022.127168.
• W. Liu, P. Liu, H. Xu, B. Gong and F. Ji, Study on the Microstructure Evolution and Strength Damage Mechanism of Dolomite under Dissolution Condition, 14, 1-14, 11447, 2022. https://doi.org/10.3390/ su141811447
• ISRM The complete ISRM suggested methods for rock characterization, testing and monitoring: 1974-2006. Kozan Ofset, Ankara, 2007.
• E. Tuncay and N. Hasancebi, The effect of length to diameter ratio of test specimens on the uniaxial compressive strength of rock, Bulletin of Engineering Geology and the Environment, 68 (4), 491–497, 2009. https://doi.org/10.1007/s10064-009-0227-9.
• M. Özdemir, Anizotropik Davranış Gösteren Metamorfik Kaya Kütlelerinde Şev Stabilitesi Analizleri. Doktor Tezi, Kütahya Dumlupınar Üniversitesi, Lisansüstü Eğitimi Enstitüsü, Kütahya, 2021.
• M. Özdemir, S. Beyhan and K. Erarslan, The Effect of Anisotropy On The Dynamıc Properties Of Schist Rocks, Journal of Scientific Reports-A, 49 (June 2022), 92–104, E-ISSN: 2687-6167, 2022.
• H. Yıldız, K. Günay, Ş. Şahin, S. F. Niğdeli and M. Y. İçli, Hanönü (Kastamonu) bakır sahası (AR: 201300022) buluculuk talebine esas maden jeolojisi ve rezerv raporu. Ankara, 2014.
• O. Çimen, M. C. Göncüoğlu and K. Sayıt, Geochemistry of the metavolcanic rocks from the Çangaldağ complex in the central pontides: Implications for the middle jurassic arc-back-arc system in the neotethyan intra-pontide ocean, Turkish Journal of Earth Sciences, 25 (6), 491–512, 2016. https://doi.org/10.3906/yer-1603-11.
• M. F. Uğuz and M. Sevin, 1:100.000 Scale Geological Maps of Turkey No:76 Kastamonu E32 Map Sheet. Ankara, 2007.
• C. Saroglou, S. Qi, S. Guo and F. Wu, ARMR, a new classification system for the rating of anisotropic rock masses, Bulletin of Engineering Geology and the Environment, (August), 2018. https://doi.org/10.1007/ s10064-018-1369-4.
• C. Saroglou and N. Bar, The ARMR classification system and the modified Hoek-Brown failure criterion compared to directional shear strength models for anisotropic rock masses, Periodica Polytechnica Civil Engineering, 64 (1), 14–19, 2020. https://doi.org/10.3311/PPci.14767.