اثر فرآیندهای یخبندان- ذوب و گرمایش – سرمایش بر نفوذپذیری ماسه سنگ لوشان

نویسندگان

1 دانشیار، گروه مهندسی معدن، دانشگاه بین المللی امام خمینی (ره)

2 دانشجوی کارشناسی، گروه مهندسی معدن، دانشگاه بین المللی امام خمینی (ره)

چکیده

در بسیاری از محیط‌ها، سنگ‌ها معمولا در معرض شرایط یخبندان – ذوب و یا گرمایش- سرمایش قرار می‌گیرند،  بنابراین ضروری است که تاثیر این فرایندها بر روی خواص فیزیکی و مکانیکی سنگ از جمله نفوذپذیری بررسی  شود. در این تحقیق از نمونه‌های ماسه سنگ سازند منطقه لوشان برای مطالعه استفاده شد و تاثیر تعداد سیکل های انجماد- ذوب و  دما در فرآیند گرمایش- سرمایش روی نفوذپذیری ماسه سنگ مورد بررسی قرار گرفت. برای بررسی اثر تعداد سیکل‌ها آزمایش‌ها روی نمونه‌هایی که 1، 5، 10 و 20 سیکل انجماد- ذوب را تحمل کرده‌اند  انجام  شد. برای بررسی اثر گرمایش – سرمایش آزمایش ها بر روی نمونه‌هایی که یک سیکل گرمایش- سرمایش را تحمل کرده‌اند و در مرحله گرمایش دمای  60، 100، 200 ، 400، 600، 800  و 1000 درجه سانتیگراد را تحمل کرده‌اند و در محیط سرد شده‌اند انجام شده است. نتایج به دست آمده حاکی از آن است که با افزایش تعداد سیکل های انجماد- ذوب میزان نفوذپذیری بعد از یک سیکل کاهش پیدا کرد  و این کاهش تا 5 سیکل ادامه می‌یابد، هر چند کاهش نفوذپذیری از 1 سیکل تا 5 سیکل بسیار ناچیز است. در 10 سیکل نفوذپذیری اندکی افزایش  می‌یابد و در 20 سیکل این افزایش چشمگیر است. همچنین با افزایش دما در مرحله گرمایش در فرآیند گرمایش – سرمایش نفوذپذیری ماسه سنگ تا 100 درجه سانتیگراد کاهش و سپس افزایش می‌یابد. تغییرات نفوذپذیری در فرآیند گرمایش – سرمایش با تغییرات سرعت امواج طولی، وزن مخصوص خشک و تخلخل موثر تطابق دارد. مقدار سی تی محاسبه شده از تصاویر سی تی اسکن  نیز تغییرات نفوذپذیری را  تایید می‌کند.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Effect Of Freeze-Thaw And Heating-Cooling Processes On Permeability Of: Lushan Sandstone

نویسندگان [English]

  • M. Hosseini 1
  • D. Fakhri 2
1 Associate Professor, Dept. of Mining Engineering, Imam Khomeini International university, Qazvin
2 B.Sc Student, Dept. of Mining Engineering, Imam Khomeini International university, Qazvin
چکیده [English]

Rocks are usually exposed to freeze-thaw and/or heating-cooling conditions in many environments. In cold regions, rocks are affected by long-time freeze and several freeze-thaw cycles. In addition, rocks are exposed to significant heat in some cases, such as explosions and fires; they are then cooled down due to fire extinguishing or cold ventilation and a heating-cooling- process occurs. Therefore, it is necessary to investigate the effects of these processes on the physical and mechanical properties of rocks, including permeability. In this research, sandstone specimens of Lushan area were applied to investigate the impact of number of freeze-thaw cycles and the effect of temperature in the heating-cooling process on sandstone permeability. The freezing temperature of -16°C was considered to study the effect of number of cycles. In this state, the tests were carried out on the specimens withstood 1, 5, 10, and 20 freeze-thaw cycles. To study the effect of heating-cooling, the tests were conducted on the specimens that withstood one heating-cooling cycle. The specimens withstood temperatures of 60, 100, 200, 400, 600, 800, and 1000 °C at the heating process and then cooled in the laboratory environment. Results indicated that permeability rate was reduced after one cycle of freeze-thaw cycles the reduction continued to 5 cycles; although, permeability reduction was negligible from cycle 1 to cycle 5. Permeability increased slightly in 10 cycles and the increase was significant in 20 cycles. Sandstone permeability was reduced up to 100 °C and then was increased with the temperature increasing at the heating-cooling process. Permeability changes in the heating-cooling process were consistent with the variations of velocity of longitudinal waves, dry unit weight, and effective porosity. CT scan images were used to examine permeability changes in the heating-cooling process and the CT value calculated by the images confirms the permeability variations.

کلیدواژه‌ها [English]

  • Sandstone
  • Permeability
  • Freeze-thaw process
  • Heating-cooling process
  • Rock
[1]     Liang. W., Xu, S., and Zhao, Y. (2006). “Experimental study of temperature effects on physical and mechanical characteristics of salt rock”. Rock Mechanics and Rock Engineering, 39: 469-482.

[2]     Qiu, Y. P., and Lin, Z. Y. (2006). “Testing study on damage of granite samples after high temperature”. Rock and Soil Mechanics, 27: 1005-1010.

[3]     Koca, M. Y., Ozden, G., Yavuz, A. B., Kincal, C., Onargan, T., and Kucuk, K. (2006). “Changes in the engineering properties of marble in fire- exposed columns”. International Journal of Rock Mechanics and Mining Sciences, 43: 520-530.

[4]     Dwivedi, R. D., Goel, R. K., Prasad, V. V. R., and Sinha, A. (2008). “Thermo- mechanical properties of Indian and other granites”. International Journal of Rock Mechanics and Mining Sciences, 45: 303-315.

[5]     Xu, X. L., Kang, Z. X., Ji, M., Ge, W. X., and Chen, J. (2009). “Research of microcosmic mechanism of brittle-plastic transition for granite under high temperature. Proc Earth and Planetary Science, 1: 432-437.

[6]     Keshavarz, M., Pellet, F., and Loret, B. (2010). “Damage and changes in mechanical properties of a gabbro thermally loaded up to 1000°C“. Pure and Applied Geophysics, 167: 1511-1523.

[7]     Luo, J. A., and Wang, L. (2011). “High-temperature mechanical properties of mudstone in the process of underground coal gasification. Rock Mechanics and Rock Engineering, 44: 749-754.

[8]     Ranjith, P. G., Viete, D. R., Chen, B. J., and Perera, M. S. A. (2012). “Transformation plasticity and the effect of temperature on the mechanical behavior of Hawkesbury sandstone at atmospheric pressure. Engineering Geology, 151: 120-127.

[9]     Sriapai, T., Walsri, C., and Fuenkajorn, K. (2012). “Effects of temperature on compressive and tensile strengths of salt. ScienceAsia, 38: 166-174.

[10]  Chen, Y. L., Ni, J., Shao, W., and Azzam, R. (2012). “Experimental study on the influence of temperature on the mechanical properties of granite under uni-axial compression and fatigue loading. International Journal of Rock Mechanics and Mining Sciences, 56: 62-66.

[11]  Broto´ns, V., Alarco´n, J. C., Toma´s, R., and Ivorra, S. (2013). “Temperature influence on the physical and mechanical properties of a porous rock: San Julians calcarenite. Engineering Geology, 167: 117-127.

[12]  Zhang, L., Mao, X., Liu, R., Guo, X., and Ma, D. (2014). “The mechanical properties of mudstone at high temperatures: an experimental study”. Rock Mech Rock Eng, 47: 1479-1484.

[13]  Hosseini, M. (2017). “Effect of temperature as well as heating and cooling cycles on rock properties”. Journal of Mining and Environment, 8(4): 631-644.

[14]  Hosseini, M., and Khodayari, A. R. (2018). “Effects of temperature and confining pressure on mode II fracture toughness of rocks (Case study: Lushan Sandstone)”. Journal of Mining and Environment, 9(2): 379-391.

[15]  Özbek, A. (2014). “Investigation of the effects of wetting–drying and freezing–thawing cycles on some physical and mechanical properties of selected ignimbrites”. Bulletin of Engineering Geology and the Environment, 73(2): 595-609.

[16]  Momeni, A., Abdilor, Y., Khanlari, G. R., Heidari, M., and Sepahi, A. A. (2016). “The effect of freeze–thaw cycles on physical and mechanical properties of granitoid hard rocks”. Bulletin of Engineering Geology and the Environment, 75(4): 1649-1656.

[17]  Li, J. L., Zhou, K. P., Liu, W. J., and Deng, H. W. (2016). “NMR research on deterioration characteristics of microscopic structure of sandstones in freeze–thaw cycles”. Transactions of Nonferrous Metals Society of China, 26(11): 2997-3003.

[18]  Tan, X., Chen, W., Yang, J., and Cao, J., (2011). “Laboratory investigations on the mechanical properties degradation of granite under freeze–thaw cycles”. Cold Regions Science and Technology, 68(3): 130-138.

[19]  Khanlari, G., Sahamieh, R. Z., and Abdilor, Y. (2015). “The effect of freeze–thaw cycles on physical and mechanical properties of Upper Red Formation sandstones, central part of Iran”. Arabian Journal of Geosciences, 8(8): 5991-6001.

[20]  Ghobadi, M. H., Beydokhti, A. T., Nikudel, M. R., Asiabanha, A., and Karakus, M. (2016). “The effect of freeze–thaw process on the physical and mechanical properties of tuff”. Environmental Earth Sciences, 75(9): 846.

[21]  Altindag, R., Alyildiz, I. S., and Onargan, T. (2004). “Mechanical property degradation of ignimbrite subjected to recurrent freeze–thaw cycles”. International Journal of Rock Mechanics and Mining Sciences, 41(6): 1023-1028.

[22]  Takarli, M., and Prince-Agbodjan1, W. (2008). “Temperature effects on physical properties and mechanical behavior of granite: experimental investigation of material damage”. Journal of ASTM International, 5(3): 1-13.

[23]  Yu, J., Chen, X., Li, H., Zhou, J. W., and Cai, Y. Y. (2015). “Effect of freeze-thaw cycles on mechanical properties and permeability of red sandstone under triaxial compression”. Journal of Mountain Science, 12(1): 218-231.

[24]  Pettijohn, F. J., Potter, P. E., and Siever, R. (1987). “Sand and Sandstonedn2 ”. Edition, Springer-Verlag, New York, pp. 553.

[25]  ISRM, (2007). “In: Ulusay, Hudson (Eds.), Suggested methods prepared by the commission on testing methods”. International Society for Rock Mechanics, ISRM Turkish National Group, Ankara, Turkey, pp. 628.

[26]  Boulin, P. F., Bretonnier, P., Gland, N., and Lombard, J. M. (2012). “Contribution of the steady state method to water permeability measurement in very low permeability porous media”. Oil & Gas Science and Technology–Revue d’IFP Energies nouvelles, 67(3): 387-401.

[27]  Lü, C., Sun, Q., Zhang, W., Geng, J., Qi, Y., and Lu, L. (2017). “The effect of high temperature on tensile strength of sandstone”. Applied Thermal Engineering, 111: 573-579.

[28]  Zhao, Z. (2016). “Thermal Influence on Mechanical Properties of Granite: A Micro cracking Perspective”. Rock Mechanics and Rock Engineering, 49(3): 747-762.

[29]  Yao, W., Xu, Y., Wang, W., and Kanopolous, P. (2016). “Dependence of dynamic tensile strength of longyou sandstone on heat-treatment temperature and loading rate”. Rock Mechanics and Rock Engineering, 49(10): 3899-3915.

[30]  Yao, W., Liu, H. W., Xu, Y., Xia, K., and Zhu, J. (2017). “Thermal degradation of dynamic compressive strength for two mortars”. Construction and Building Materials, 136: 139-152.

[31]  Huang, S., and Xia, K. (2015). “Effect of heat-treatment on the dynamic compressive strength of Longyou sandstone”. Engineering Geology, 191: 1-7.