알긴산 나트륨을 보강한 지반의 함수특성을 고려한 저수지 사면안정성 평가 = Slope Stability Evaluation of Reservoir Considering Soil-water Characteristic Curve of the Reinforced Ground Including Alginic Acid Sodium Salt

다국어 초록 (Multilingual Abstract)

Alginic acid sodium salt is a type of biopolymer. It is a polysaccharide obtained from the most widely distributed brown algae among marine plants. Its main characteristics are nontoxicity and biodegradability. It is also considered a natural eco-friendly material because it is completely decomposed by microorganisms using only water and carbon dioxide. Moreover, sodium alginate aqueous solution mixed with water has high viscosity; hence, it is expected to effectively saturate and reinforce the soil. The soil-water characteristic curve shows the properties of the capillary pressure according to the water content of the soil. In other words, this curve can predict the shear strength of the soil. In this study, soil-water characteristic curves of soil reinforced with sodium alginate were studied. The stability of the reservoir slope reinforced with sodium alginate was evaluated using the input values of the numerical analysis, and the change in the shear strength of the soil was calculated. The results show that the increased concentration of sodium alginate solution increased the capillary pressure and residual water content of the soil-water characteristic curve, which increased the stability of the reservoir slope. The shear strength of the soil increased as the concentration and capillary pressure of the sodium alginate solution increased.

국문 초록 (Abstract)

바이오폴리머의 일종인 알긴산 나트륨은 해양 식물 중 가장 많이 분포된 갈조류로부터 얻어지는 다당류로서 무독성 및생분해성을 나타낸다. 알긴산 나트륨은 미생물에 의해 물과 이산화탄소만으로 완전히 분해되기 때문에 자연 친환경적인재료로 여겨진다. 또한, 물과 혼합된 수용액은 지반의 공극에 주입하여 강도를 보강하는 데 효과적으로 기대된다. 함수특성곡선은지반의 함수비에 따른 모관흡수력의 특성을 나타내는 곡선으로써, 지반의 투수성 및 전단강도 변화를 예측할 수 있다. 본연구에서는 알긴산 나트륨으로 보강된 지반의 함수특성곡선을 산정하였다. 실험으로 산정된 함수특성곡선을 수치해석의입력값으로 활용하여 알긴산 나트륨으로 보강된 저수지 사면의 안정성을 평가하였다. 또한, 함수특성곡선 및 이론식을 활용하여알긴산 나트륨 보강 및 함수비에 따른 지반의 전단강도 변화를 산정하였다. 그 결과, 알긴산 나트륨 수용액의 농도가 증가할수록지반의 공기주입압력 및 잔류포화도가 증가하고, 저수지 사면의 안정성이 증가함을 확인하였다. 또한, 알긴산 나트륨 수용액의농도 및 모관흡수력이 증가할수록 지반의 전단강도는 증가함을 확인하였다.

참고문헌 (Reference)

1 박고은, "알긴산나트륨/PEO, 알긴산나트륨/PVA 나노섬유의 제조 및 특성분석" 한국고분자학회 32 (32): 206-212, 2008

2 Kim, D. H., "Unsaturated characteristics and slope stability analysis of weathered granitic soils" Kangwon National University 2010

3 Kim, B. S., "The effect of rainfall patterns on slope stability in unsaturated weathered soils" Dankook University 2007

4 Shin, J. S., "The analysis and prediction of unsaturated characteristic for Nak-dong River silty sand" Kyungpook National University 2011

5 Fredlund, D. G., "State variables in saturatedunsaturated soil mechanics" 39 (39): 3-17, 2016

6 GEO-SLOPE International Ltd, "Stability modeling with SLOPE/W"

7 Jung, J., "Soil–water characteristic curve of sediments containing a polyacrylamide solution" 6 (6): 89-94, 2016

8 GEO-SLOPE International Ltd, "Seepage modeling with SEEP/W"

9 Vanapalli, S. K., "Model for the prediction of shear strength with respect to soil suction" 33 (33): 379-392, 1996

10 Fredlund, D. G., "Evaluation of hysteresis models for predicting the boundary wetting curve" 407-412, 2003

11 Fredlund, D. G., "Estimation of soil suction from the soil-water characteristic curve" 48 (48): 186-198, 2011

12 Fredlund, D. G., "Equations for the soilwater characteristic curve" 31 (31): 521-532, 1994

13 Pham, H. Q., "Equations for the entire soil-water characteristic curve of a volume change soil" 45 (45): 443-453, 2008

14 Cao, S. C., "Engineering behavior and characteristics of watersoluble polymers : Implication on soil remediation and enhanced oil recovery" 8 (8): 205-, 2016

15 Pham, H. Q., "A study of hysteresis models for soil-water characteristic curves" 42 (42): 1548-1568, 2005