DOI QR코드

DOI QR Code

Effect of Hydraulic Conductivity on Suction Profile and Stability of Cut-Slope during Low Intensity Rainfall

저강도 강우시 절토사면의 흡인력 분포와 안정성에 대한 투수계수의 효과

  • Khalid, Mahmood (Dept. of Civil Engineering, Pusan National University) ;
  • Kim, Jin-Man (Dept. of Civil Engineering, Pusan National University)
  • Received : 2012.03.17
  • Accepted : 2012.06.12
  • Published : 2012.06.29

Abstract

The authors discuss the effect of hydraulic conductivity on the suction profile and stability of a typical cut-slope subjected to low intensity rainfall. The initial suction value above the ground table in the unsaturated zone is assumed to be 15 kPa. The uncoupled approach of finite element and limit equilibrium method is used to evaluate the stability of the cut-slope at different elapsed times of rainfall. The finite element seepage analysis shows that the soil in the unsaturated zone always remains unsaturated during the course of low intensity rainfall. Furthermore, the slope stability remains practically unchanged so long as the wetting front remains in the unsaturated zone but it decreases noticeably when the wetting front reaches and elevates the ground water table level.

저강도 강우상태에서 투수계수가 일반적인 절토사면의 흡인력 분포와 안정성에 어떤 영향을 주는지를 평가하였다. 지하수면 위의 불포화 지층의 초기 흡인력을 15 kPa로 가정하였다. 강우 지속시간 증가에 따른 절토사면의 안정성을 평가하기 위해 유한요소법과 한계평형법을 사용하였다. 유한요소 침투해석 결과, 저강도 강우상태에서는 불포화 지층이 계속해서 불포화 상태로 유지되는 현상을 보였다. 또한, 침윤선(wetting front)이 불포화 지층에 남아있는 경우에는 사면의 안정성에 사실상 변화가 없었으나, 침윤선(wetting front)이 지하수면에 도달하는 경우에는 지하수면이 높아짐에 따라 사면안정성이 크게 저하되었다.

Keywords

References

  1. Boumans, J. H. (1976). "Drainage calculations in stratified soils using the anisotropic soil model to simulate hydraulic conductivity conditions." In: J. Wesseling (ed.), Proceedings of the international drainage workshop. ILRI Publication 25, Wageningen, pp. 108-123.
  2. Brand, E. W. (1992). "Slope stability in tropical areas." Proceedings of the 6th International Symposium on Landslides, Christchurch, New Zealand, V. 1, pp. 2031-2051.
  3. Fredlund, D. G., Rahardjo, H. (1993). "Soil mechanics for unsaturated soils." Wiley, New York
  4. Fredlund, D. G., Xing, A. (1994). "Equations for the soil-water characteristic curve." Canadian Geotechnical Journal, Vol. 31(3), pp. 521-532. https://doi.org/10.1139/t94-061
  5. Freez, R. A., Cherry, J. A. (1979). "Groundwater." Prentice-Hall, Inc, New Jersey, pp 604
  6. Gavin, K., Xue, J. (2008). "A simple method to analyze infiltration into unsaturated soil slopes." Computers and Geotechnics, Vol. 35(2), pp. 223-230. https://doi.org/10.1016/j.compgeo.2007.04.002
  7. Green, W. H., Ampt, C. A. (1911). "Studies on soil physics: flow of air and water through soils." J. Agric. Sci., Vol. 4, pp. 1-24. https://doi.org/10.1017/S0021859600001441
  8. Kim, J. M. (2001). "Probabilistic approach to evaluation of earthquake induced permanent deformation of slopes." PhD thesis, University of California Berkeley USA.
  9. Lee, S. R., Kim, Y. K., Choi. J. Y. (2005). "Application of unsaturated soil parameters to slope design against rainfall infiltrationinduced instability." Proceedings of International Conference on Problematic Soils, Eastern Mediterranean University, Famagusta, N. Cyprus, pp. 175-182.
  10. Mahmood, K., Ryu Jeong Ho, Jin, Man Kim, "Effect of anisotropic conductivity on suction and reliability index of unsaturated slope exposed to uniform antecedent rainfall." Journal of Landslide, Accepted on March 8th 2012.
  11. Mein, R. G., Larson, C. L. (1973). "Modeling infiltration during a steady rain." Water Resour. Res, Vol. 9(2), pp. 384-394. https://doi.org/10.1029/WR009i002p00384
  12. Pradel, D., and Radd, G. (1993). "Effect on permeability on surficial stability of homogeneous slopes." J. Geotech. Eng., ASCE, Vol. 119(2), pp. 315-332. https://doi.org/10.1061/(ASCE)0733-9410(1993)119:2(315)
  13. Rahardjo, H., (2000). "Rainfall-induced slope failures." Research Report. No. NSTB 17/6/16, Nanyang Technological University, Singapore
  14. Wang, D., and Sassa, K. (2003). "Pore-pressure generation and movement of rainfall induced landslide: Effect of grain size and fine-particle content." Engineering Geology, Vol. 69. pp. 109-125. https://doi.org/10.1016/S0013-7952(02)00268-5

Cited by

  1. The probabilistic stability analysis of saturated-unsaturated MH and CL soil slope with rainfall infiltration pp.1976-3808, 2017, https://doi.org/10.1007/s12205-017-1052-5
  2. Assessing the Effects of Rainfall Intensity and Hydraulic Conductivity on Riverbank Stability vol.11, pp.4, 2012, https://doi.org/10.3390/w11040741
  3. Influence of rainfall infiltration on the stability of unsaturated coal gangue accumulated slope vol.18, pp.6, 2021, https://doi.org/10.1007/s11629-020-6567-4