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Analysis of Rock Surface Roughness and Chemical Species Generation by Freeze-Thaw Experiments

동결융해 실험을 통한 암석 표면 거칠기 및 화학종 생성에 관한 분석

  • Choi, Junghae (Kyungpook National University, Department of Earth Science Education)
  • 최정해 (경북대학교 지구과학교육과)
  • Received : 2022.08.22
  • Accepted : 2022.09.01
  • Published : 2022.09.30

Abstract

Rocks exposed to the surface are subject to long-term weathering, and such effects weaken their engineering stability. Especially as weathering progresses, the surface of rocks will be changed by weathering, and such surface changes will affect the engineering safety of the rock mass. In addition, the chemical species produced in the weathered rock have a direct effect on the surrounding environment or on the structure. In areas where rocks are exposed, such as mining areas, chemical species produced by weathering can have a serious impact on the surrounding natural environment. In this study, accelerated weathering experiments using freeze/thaw system were conducted on rocks that had already been weathered and fresh rocks, and surface changes of each rock were observed with confocal laser scanning microscope (CLSM), and chemical species were analyzed using IC/ICP-MS. As the weathering progressed, the surface roughness decreased, and the amount of chemical species produced increased. The results of this study can be used as basic data for evaluating engineering/environmental safety in areas where rocks are exposed.

지표에 노출된 암석은 지속적으로 풍화를 받게 되고 이러한 영향으로 암석의 공학적 안정성이 약해지게 된다. 특히 풍화가 진행되면서 암석의 표면은 풍화에 의해서 변화를 일으키고 이러한 표면 변화는 암석으로 구성된 지반의 공학적 안전성에 영향을 미치게 된다. 또한, 풍화를 받은 암석에서 생성되는 화학종은 주변환경에 직접적인 영향을 미치거나 구조물에 영향을 미치게 된다. 광산지역과 같이 암석이 노출된 지역에서는 풍화에 의해 생성된 화학종이 주변 자연환경에 심각한 영향을 미치기도 한다. 본 연구에서는 이러한 관점에서 동결/융해 실험을 활용한 풍화가속 실험을 이미 풍화를 받은 암석과 신선한 암석을 대상으로 실시하고 각 암석의 표면 변화를 다초점 레이저 현미경으로 관찰하고 IC/ICP-MS를 활용하여 화학종 생성에 대한 분석을 실시하였다. 풍화가 진행됨에 따라 표면의 거칠기는 완화되는 것을 확인하였고 주변환경에 영향을 미칠 수 있는 화학종은 풍화를 받는동안 양이 증가하는 것을 확인하였다. 본 연구 결과는 암석이 노출된 지역에서의 공학적/환경학적 안전성을 평가하는 기초 자료로 활용될 수 있을 것이다.

Keywords

Acknowledgement

이 논문은 2022년도 원자력안전위원회의 재원으로 사용후핵연료관리핵심기술개발사업단 및 한국원자력안전재단의 지원을 받아 수행된 연구사업임.

References

  1. 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 & Mining Sciences, 41(6), 1023-1028. https://doi.org/10.1016/j.ijrmms.2004.03.005
  2. ISRM, 1981, Rock characterization testing & monitoring (ISRM suggested method), Brown, E.T., ed., Pergamon Press, 211p.
  3. Jang, H.S., Jang, B.A. and Lee, J.S., 2004, Variations of engineering geological characteristics of the cretaceous shale from the pungam sedimentary basin in Kangwon-do due to freezing-thawing, The Journal of Engineering Geology, 14(4), 401-416. (In Korean with English abstract)
  4. Kang, S.S., Kim, J.T., Obara, Y. and Hirata, A., 2011, Estimation of weathering characteristics of sandstone and andesite by freeze-thaw test, Tunnel & Underground Space, Journal of Korean Society for Rock Mechanics, 21(2), 145-150. (In Korean with English abstract)
  5. Liu, Q.S., Xu, G.M. and Liu, X.Y., 2008, Experimental and theoretical study on freeze-thawing damage propagation of saturated rocks, International Journal of Modern Physics B, 22, 1853-1858. https://doi.org/10.1142/S0217979208047523
  6. Mutluturk, M., Altindag, R. and Turk, G., 2004, A decay function model for the integrity loss of rock when subjected to recurrent cycles of freezing-thawing and heating-cooling, International Journal of Rock Mechanics & Mining Sciences, 41(2), 237-244. https://doi.org/10.1016/S1365-1609(03)00095-9
  7. Nicholson, D.T., Nicholson, F.H., 2000, Physical deterioration of sedimentary rocks subjected to experimental freeze-thaw weathering, Earth Surface Processes and Landforms, 25(12), 1295-1307. https://doi.org/10.1002/1096-9837(200011)25:12<1295::AID-ESP138>3.0.CO;2-E
  8. Olympus, 2017, Introduction to surface roughness measurement, Olympus Corporation.
  9. Park, Y.J., You, K.H., Yang, K.Y., Woo, I., Park. C. and Song, W.K., 2003, Weathering characteristics of granite by freeze-thaw cyclic test, Tunnel & Underground Space, 13(3), 215-224. (In Korean with English abstract)
  10. Ryu, S.H. and Song, J.J., 2012, Weathering of Rock Specimens Exposed to Recurrent Freezing and Thawing Cycles, Tunnel & Underground Space, 22(4), 276-283. (In Korean with English abstract) https://doi.org/10.7474/TUS.2012.22.4.276
  11. Takarli, M., Prince, W. and Siddique, R., 2008, Damage in granite under heating/cooling cycles and water freeze-thaw condition, International Journal of Rock Mechanics & Mining Sciences, 45(7), 1164-1175. https://doi.org/10.1016/j.ijrmms.2008.01.002
  12. Tan, X.J., Chen, W.Z., Yang, J.P. and Cao, J.J., 2011, Laboratory investigations on the mechanical properties degradation of granite under freeze-thaw cycles, Cold Regions Science and Technology, 68(3), 130-138. https://doi.org/10.1016/j.coldregions.2011.05.007
  13. Um, J.G. and Shin, M.K., 2009, Variations of physico-mechanical properties of the cretaceous mudstone in Haman, Gyeongnam due to freeze-thaw weathering, Tunnel & Underground Space, 19(2), 146-157. (In Korean with English abstract)
  14. Yang, J.H., 2011, The effect of a freeze-thaw cycle on rock weathering: laboratory experiments, Journal of the Korean Geomorphological Association, 18(3), 21-36. (In Korean with English abstract)
  15. Yavuz, H., Altindag, R., Sarac, S., Ugur, I. and Sengun, N., 2006, Estimating the index properties of deteriorated carbonate rocks due to freeze-thaw and thermal shock weathering, International Journal of Rock Mechanics & Mining Sciences, 43(5), 767-775. https://doi.org/10.1016/j.ijrmms.2005.12.004
  16. Yavuz, H., 2011, Effect of freeze-thaw and thermal shock weathering on the physical and mechanical properties of an andesite stone, Bulletin of Engineering Geology and the Environment, 70(2), 187-192. https://doi.org/10.1007/s10064-010-0302-2