동결-융해 풍화에 의한 암석 물성 변화 양상과 추정에 관한 연구
Weathering of Rock Specimens Exposed to Recurrent Freezing and Thawing Cycles
0
조회
0
다운로드
8
인용
0
참고문헌
키워드
초록
화강암(풍화), 석회암, 사암, 응회암, 셰일, 현무암 등 6가지 국내 암석을 대상으로 동결-융해에 의한 암석의 풍화과정을 실험하였다. 동결-융해 시 온도범위는 -20℃~10℃로 최대 40회까지 동결-융해를 반복하면서 비중, 공극률, 탄성파 속도, 쇼어경도를 측정하였다. 동결-융해 횟수가 증가함에 따라 공극률이 큰 화강암(w), 셰일, 현무암의 경우 기존의 균열이 성장하는 것이 뚜렷이 관찰되었고 시험편이 상하부로 분리되기도 하였다. 비중의 변화는 뚜렷이 관찰되지 않았다. 화강암(w), 셰일, 현무암의 탄성파 속도와 쇼어경도 값은 동결-융해에 의해 크게 감소하였고 석회암, 사암, 응회암의 경우 그 변화폭이 작았다. 공극률의 경우 인장강도가 작은 화강암(w), 셰일, 현무암이 크게 증가하였고 나머지 암종은 거의 변화하지 않았다. 실험 결과를 이용하여 선형 회귀식을 도출하였고, 각 회귀식의 계수와 동결-융해 풍화 민감도(= 초기 공극률 / 초기 인장강도)와의 상관관계를 살펴보았다. 이를 이용하여 암석의 초기 물성 값만으로도 동결-융해에 의한 풍화를 예측 가능할 것으로 판단된다.
Abstract
Changes in rock properties due to freezing and thawing cycles ranging from -20℃ to 10℃ were checked for the typical Korean rocks: granite (weathered), limestone, sandstone, tuff, shale and basalt. The porosity, seismic velocity, shore hardness and specific gravity were measured every 10 cycles for each type of rock up to 40 cycles. The specific gravity was rarely changed. Granite (w), shale and basalt decreased gradually in their shore hardness and seismic velocity values, these values for limestone, sandstone and tuff changed only a very little. The porosity increased in the granite (w), shale and basalt, whereas in the others it did not change. Due to the low tensile strength with high porosity, granite (w), shale and basalt were susceptible to the F-T cycles. A linear regression equation was calculated based on the experiment results according to properties and types of rock. The relationship between the freeze-thaw sensitivity (= initial porosity / initial tensile strength) and the coefficients of the regression equation was examined. With additional experimental data, the coefficients of the regression equation can be estimated using the F-T sensitivity. This makes it possible to predict the properties of rock as affected by freeze-thaw weathering by only measuring the initial properties without knowledge of the regression equation coefficients for each type of rock.
참고문헌 (21)
- C. Park, "Experimental study on the thermal characteristics of rock at low temperatures", Proceedings of the ISRM SICNOROCK 2004 Symposium, 1, pp.14~ (2004)
- Dawn T. Nicholson, "Physical deterioration of sedimentary rocks subjected to experimental freeze-thaw weathering", Earth Surface Processes and Landforms, 25, pp.1295~1307 (2000)
- H. Yavuz, "Estimating the index properties of deterioratedcarbonate rocks due to freeze–thaw and thermal shockweathering", Journal of Rock Mechanics &Mining Sciences, 43, pp.767~775 (2006)
- Hall, K, "The role of thermal stress and fatigue in the breakdown of rock in cold regions", Geomorphology, 31, pp.47~63 (1999)
- Huseyin Yavuz, "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, pp.187~192 (2011)
- 장현식, "강원도 횡성군 풍암분지 백악기 셰일의 동결 - 융해에 따른 지질공학적 특성 변화", 지질공학, 14(4), pp.401~416 (2004), 대한지질공학회
- Kim, H, "Geochronologic evidence for early cretaceous volcanic activity on Barton Peninsula, King George Island, Antarctica", Polar Research, 19, pp.251~260 (2000)
- Korea Polar Research Institute, "Weather Annual Report of Antarctic King Sejong Station (2005~2006)", 178~ (2007)
- Lee, Y.I, "Geochemistry of soils of King George Island, South Shetland Islands, West Antarctica: Implications for pedogenesis in cold polar regions", Geochimica et Cosmochimica Acta, 68, pp.4319~4333 (2004)
- M. Mutlutürk, R, "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, pp.237~244 (2004)
- Mokhfi Takarli, "Damage in granite under heating", cooling cycles and water freeze–thaw condition, 2008, pp.45, 1164~1175
- Quansheng LIU, "Experimental and theoretical study on freeze-thawing damage propagation of saturated rocks", International Journal of Modern Physics B, 22, pp.1853~1858 (2008)
- R. Altindag, "Mechanical property degradation of ignimbrite subjected to recurrent freeze–thaw cycles", International Journal of Rock Mechanics & Mining Sciences, 41, pp.1023~1028 (2004)
- 강성승, "동결융해시험에 의한 사암 및 안산암의 풍화특성 평가", 터널과 지하공간, 21(2), pp.145~150 (2011), 한국암반공학회
- T.C. Chen, "Effect of water saturation on deterioration of welded tuff due to freeze– thaw action", Cold Regions Science and Technology, 38, pp.127~136 (2004)
- Methods of testing for natural buildings stones (TS 699), "TSE", Institute of Turkish Standards, 82~ (1987)
- 엄정기, "경남 함안군 백악기 이암의 동결-융해에 따른물성변화 및 미세균열 발현특성", 터널과 지하공간, 19(2), pp.146~157 (2009), 한국암반공학회
- Xianjun Tan, "Laboratory investigations on the mechanical properties degradation of granite under freeze-thaw cycles", Cold Regions Science and Technology, 68, pp.130~138 (2011)
- 양재혁, "동결-융해작용에 따른 암석풍화의 특성", 한국지형학회지, 18(3), pp.21~36 (2011), 한국지형학회
- Jeong Pil Yeo, "Geochemistry of volcanic rocks in Barton and Weaver peninsulas, King George Island, Antarctica: Implications for arc maturity and correlation with fossilized volcanic centers", Geosciences Journal, 8(1), pp.11~25 (2004), 한국지질과학협의회
- 박연준, "동결-융해 시험에 의한 화강암의 풍화 특성 연구", 터널과 지하공간, 13(3), pp.215~224 (2003), 한국암반공학회