ارزیابی شاخص‌های شکنندگی سنگ‌ها، برای تخمین مدول چقرمگی

نوع مقاله : مقاله پژوهشی

نویسندگان

1 دانشیار گروه زمین شناسی دانشگاه همدان

2 دانشجوی دکتری زمین شناسی مهندسی، دانشکده علوم، دانشگاه بوعلی سینا همدان

3 استادیار، دانشکده فنی و مهندسی، دانشگاه تربیت مدرس تهران

4 دکتری زمین شناسی مهندسی، دانشکده علوم، دانشگاه فردوسی مشهد

چکیده

شکنندگی و مدول چقرمگی سنگ‌ها از جمله خصوصیات ذاتی آن‌هاست که نقش تعیین کننده‌ای در عملیات حفاری سنگ‌ها دارند. در این پژوهش خواص مکانیکی سنگ‌های گرانیت، گرانودیوریت، دولومیت، هورنفلس و مرمر در محدوده پروژه تونل انتقال آب گلاس در حاشیه شهرستان نقده مطالعه شده است. با بهره‌گیری از سطح زیر منحنی تنش-کرنش و هم‌چنین خواص مقاومتی سنگ‌های مذکور، 13 شاخص شکنندگی و مدول چقرمگی محاسبه شده است. روابط آماری بین شاخص‌های شکنندگی با مدول چقرمگی نشان دهنده ارتباط قوی بین شاخص شکنندگی B3 (ضرایب تعیین 83/0 R2 = و 46/5 = RMSE) و شاخص شکنندگی B4 (ضرایب تعیین 83/0R2 = و 85/3 = RMSE) با مدول چقرمگی سنگ‌ها است. رابطه آماری بین مدول چقرمگی سنگ و انرژی ویژه برش نشان دهنده ارتباط قوی (85/0R2 =) بین این دو پارامتر می‌باشد. به طوری که با افزایش مدول چقرمگی، میزان انرژی ویژه برش سنگ افزایش می‌یابد. در این تحقیق با استفاده از مدول چقرمگی سنگ‌ها، مقدار انرژی ویژه برش آن‌ها تخمین زده شده است.

کلیدواژه‌ها


عنوان مقاله [English]

Evaluation brittleness indices of rocks, implication for estimating their toughness modulus

نویسندگان [English]

  • Mojtaba Heydari 1
  • seyed sajjad karrari 2
  • Jafar Khademi Hamidi 3
  • Ebrahim Sharifi teshnizi 4
1 Associate Prof. of Engineering Geology Bouali University
2 Department of Geology, Faculty of Science, Bu-Ali Sina University, Hamedan
3 Department of Mining Engineering, Faculty of Engineering, Tarbiat Modares University, Tehran
4 Department of Geology, Faculty of Science, Ferdowsi University, Mashhad
چکیده [English]

Brittleness and modulus of toughness are among the most important inherent properties of rock, which are determinative for rock excavation operations. In this study, mechanical properties of granite, granodiorite, dolomite, hornfels and marble were studied in the area of Glass water supply tunnel near the Naghadeh city (NW Iran). The stress-strain curve area and rocks strength properties were applied to calculate 13 brittleness indices and modulus of toughness. Statistic relationships between brittleness indices and toughness of modulus suggest strong correlation between B3 brittleness index (R2= 0.83 and RMSE= 5.46 coefficients) and B4 brittleness index (R2= 0.83 and RMSE= 3.85) respectively with modulus of toughness. The statistical relationship between modulus of toughness and specific energy indicates a strong correlation (R2= 0.85). The modulus of toughness and brittleness are useful parameters for estimating specific energy of rock cutting. Since the modulus of toughness increases with specific energy of rock cutting, it enabled us to estimate the specific energy of rock cutting.

کلیدواژه‌ها [English]

  • brittleness
  • modulus of toughness
  • specific energy
  • Glass tunnel
Altindag, R., 2002. The evaluation of rock brittleness concept on rotary blast hold drills, Journal of the Southern African Institute of Mining and Metallurgy, 102(1): 61-66.
Altindag, R., 2003. Correlation of specific energy with rock brittleness concepts on rock cutting, Journal of The Southern African Institute of Mining and Metallurgy, 103: 163-171.
Altindag, R., Guney,A., 2010. Predicting the relationships between brittleness and mechanical properties (UCS, TS and SH) of rocks, Scientific research and Essays, 5(16): 2107-2118.
Andreev, GE., 1995. Brittle failure of rock materials: test results and constitutive models, A. A. Balkema, Rotterdam, 446 p.
Ayatollahi, M.R., Akbardoost, J., 2013. Size and Geometry Effects on Rock Fracture Toughness: Mode I Fracture, Rock Mechanic Rock Engineering, 1-11.
ASTM., 2001. Standard Practice for Preparing Rock Core Specimens and Determining Dimensional and Shape Tolerances, American Society for Testing and Materials, D4543.
ASTM., 2004. Test method for compressive strength and elastic moduli of intact rock core specimens under varying states of stress and temperatures, D7012-04.
ASTM., 2008. Standard test method for splitting tensile strength of intact rock core specimens, D3967-08.
Chen, J., Zhang, G., Chen, H., Yin, X., 2014. The Construction of Shale Rock Physics Effective Model and   
       Prediction of Rock Brittleness, SEG Annual Meeting, Society of Exploration Geophysicists: 2861-2865.
Copur, C., 2003. A set of indices based on indentation tests for assessment of rock cutting performance and rock properties, Journal of The Southern African Institute of Mining and Metallurgy, 103: 589-599.
Copur, H., Bilgin, N., Tuncdemir, H., 2003. A set of indices based on indentation tests for assessment of rock cutting performance and rock properties, Journal of The Southern African Institute of Mining and Metallurgy, 103(9): 589–599.
Comakli, R., Kahraman, S., Balci, C., Tumac, D., 2016. Estimating specific energy from the brittleness indexes in cutting metallic ores, Journal of The Southern African Institute of Mining and Metallurgy, 116: 763-768.
Gong, Q. M., Zhao, J., 2007. Influence of rock brittleness on TBM penetration rate in Singapore granite, Tunnelling and Underground Space Technology, 22 (3): 317–324.
Goktan, R.M., Yilmaz, N.G., 2005. A new methodology for the analysis of the relationship between rock brittleness index and drag pick cutting efficiency, The Journal of The South African Institute of Mining and Metallurgy, 105 (10):727–734.
Goodway, B., Perez, M., Varsek, J., Abaco, C., 2010. Seismic petrophysics and isotropicanisotropic AVO methods for unconventional gas exploration, The Leading Edge, 29 (12): 1500-1508.
Hajiabdolmajid, V., Kaiser, P., 2003. Brittleness of rock and stability assessment in hard rock tunnelling, Tunnlling Underground Space Technology, 18: 35–48.
Hucka, V., Das, B., 1974. Brittleness determination of rocks by different methods, International Journal Rock Mechanics and Mining Sciences & Geomechanics Abstracts, 11: 389-392.
Jarvie, D.M., Hill, R.J., Ruble, T.E., Pollastro, R.M., 2007. Unconventional shale-gas systems: The Mississippian Barnett Shale of north-central Texas as one model for thermogenic shale-gas assessment, AAPG Bulletin, 91(4): 475-499.
Kahraman, S., 2002. Correlation of TBM and drilling machine performances with rock brittleness, Engineering Geology, 65(4): 269–283.
Lawn, B.R., Marshall D.B., 1979. Hardness, toughness and brittleness: an indentation analysis, Journal of the American Ceramic Society, 62 (7–8): 347–350.
Luan, X., B, Di., J, Wei., X, Li., K, Qian., J, Xie., P, Ding., 2014. Laboratory Measurements of Brittleness Anisotropy in Synthetic Shale with Different Cementation, SEG Annual Meeting. Denver, Society of Exploration Geophysicists: 3005-3009.
Meng, F., Zhou, H., Zhang, C., Xu, R., Lu, J., 2015. Evaluation methodology of brittleness of rock based on postpeak stress–strain curves, Rock Mechanics and Rock Engineering, 48(5): 1787-1805.
Nejati, H., Moosavi S.A., 2017. A new brittleness index for estimation of rock fracture toughness, Journal of Mining and Environment, 8: 83-91.
Ozfirat, M.K., Yenice, H.F., Simsir, O., Yarali, O., 2016. A new approach to rock brittleness and its usability at prediction of drillability, Journal of African Earth Sciences, 119: 94-101.
Quinn J.B., Quinn, G.D., 1997. Indentation brittleness of ceramics: a fresh approach, Journal of Materials Science, 32(16): 4331– 4346.
Reichmuth, D.R., 1967. Point load testing of brittle materials to determine tensile strength and relative brittleness. The 9th US Symposium on Rock Mechanics (USRMS), American Rock Mechanics Association, 134 –159.
Rickman, R., Mullen, M.J., Petre, J.E., Grieser, W.V., Kundert, D., 2008. A practical use of shale petrophysics for stimulation design optimization: All shale plays are not clones of the Barnett Shale, SPE Annual Technical Conference and Exhibition, Society of Petroleum Engineers.
Suorineni, F.T., Chinnasane, D.R., Kaiser, P.K., 2009. A procedure for determining rock-type specific Hoek-Brown brittle parameters, Rock Mechanics and Rock Engineering, 42(6): 849–881.
Sun, S.Z., Wang, K.N., Yang, P., Li, X.G., Sun, J.X., Liu, B.H., Jin, K., 2013. Integrated Prediction of Shale Oil Reservoir Using Pre-Stack Algorithms for Brittleness and Fracture Detection, Beijing, International Petroleum Technology Conference.
Tarasov, B.G., Potvin, Y., 2012. Absolute relative and intrinsic rock brittleness at compression, Mining Technology, 121(4): 218–225.
Tarasov, B., Potvin, Y., 2013. Universal criteria for rock brittleness estimation under triaxial compression, International Journal of Rock Mechanics & Mining Sciences, 59: 57–69.
Tiryaki, B., 2006. Evaluation of the indirect measures of rock brittleness and fracture toughness in rock cutting, The Journal of The South African Institute of Mining and Metallurgy, 106: 407-423.
Yagiz, S., 2009. Assessment of brittleness using rock strength and density with punch penetration test, Tunnelling and Underground Space Technology, 24(1): 66-74.
Yarali, O., Soyer, E., 2011. The effect of mechanical rock properties and brittleness on drillability, Scientific Research and Essays, 6(5): 1077-1088.
Zhang, D., Ranjith, P.G., Perera, M.A., 2016. The brittleness indices used in rock mechanics and their application in shale hydraulic fracturing: a review, Journal Petroleum Science Engineering, 143:158–170.