Scientific Quarterly Journal of Iranian Association of Engineering Geology

Scientific Quarterly Journal of Iranian Association of Engineering Geology

Matrix suction effect on the soil stability in unsaturated soil

Document Type : Original Article

Authors
Ali Akhtarpour 1
Narges Soleimanian 2
Amin Ekramifard 2
Amirabbas Riyahikhoo 2
1 Associate Professor, Civil Engineering Department, Faculty of Engineering, Ferdowsi University of Mashhad
2 PHD Candidate, Civil Engineering Department, Faculty of Engineering, Ferdowsi University of Mashhad
Abstract
In recent years, high-rise buildings have widely increased in cities, and there is an increasing need to excavate deep tranche to use the available space efficiently. One of the ways to stabilize the tranche is to use metal piles and an anchorage system. In many cases, tranche failure is due to rains, the explosion of water pipes, absorbing wells, and artesian layers. Due to these factors, matrix suction decreases, and pore water pressure increases. As a result, parameters of the shear strength of the soil weaken, and instability occurs. In the present research, using numerical simulation through SEEP/W and Slope/W software and considering two types of soil, i.e., sand and clay, the effect of water pipe explosion, the existence of an absorbing well and artesian layer is examined on the stability of a tranche stabilized by anchorage and metal pile over time. Also, the effect of the change in water pipe position, absorbing well, and the artesian layer is studied on the tranche's safety factor. The results show that as the water pipe's distance and absorbing well increases from the failure zone, the safety factor increases. Also, as the artesian layer's distance increases from the tranche floor, the safety factor increases.
Keywords
Unsaturated Soil
Stabilized Analysis
Water Pipe Explosion
Absorbing Well
Artesian Layer
Ahmadi, H., Arabani, M. and Kalantary, F., 2007. Development of Failure Criterion for Partially Saturated Cohesive Soils. International Journal of Geotechnic Engineering, 21.
Blight, G.E., 1967. Effective stress evaluation for unsaturated soils. Journal of the soil mechanics and foundations division, 93(2): 125-148.
Carsel, R.F. and Parrish, R.S., 1988. Developing joint probability distributions of soil water retention characteristics. Water resources research, 24(5): 755-769.
Elias, V. and Juran, I., 1991. SOIL NAILING FOR STABILIZATION OF HIGHWAY SLOPES AND EXCAVATIONS. FINAL REPORT (No. FHWA-RD-89-198).
Escario, V., 1980. Suction controlled penetration and shear tests. In Expansive Soils. ASCE. 781-797.
Fan, C.C. and Luo, J.H., 2008. Numerical study on the optimum layout of soil–nailed slopes. Computers and Geotechnics, 35(4): 585-599.
Fredlund, D.G., Morgenstern, N.R. and Widger, R.A., 1978. The shear strength of unsaturated soils. Canadian geotechnical journal, 15(3): 313-321.
Fredlund, D.G. and Rahardjo, H., 1993. Soil mechanics for unsaturated soils. John Wiley & Sons.
Fredlund, D.G. and Xing, A., 1994. Equations for the soil-water characteristic curve. Canadian geotechnical journal, 31(4): 521-532.
Jones, C.P., 1991. In-situ techniques for reinforced soil. In Performance of reinforced soil structures. Thomas Telford Publishing, 277-282.
Kim, S.J., Hyun, Y. and Lee, K.K., 2005. Time series modeling for evaluation of groundwater discharge rates into an urban subway system. Geosciences Journal, 9(1): 15-22.
Kumar, S. and Malik, R.S., 1990. Verification of quick capillary rise approach for determining pore geometrical characteristics in soils of varying texture. Soil Science, 150(6): 883-888.
Lam, L., Fredlund, D.G. and Barbour, S.L., 1987. Transient seepage model for saturated–unsaturated soil systems: a geotechnical engineering approach. Canadian Geotechnical Journal, 24(4): 565-580.
Lane, K.S., Washburn, D.E. and Krynine, D.P., 1947. Capillarity tests by capillarimeter and by soil filled tubes. In Highway research board proceedings (Vol. 26).
Lu, N. and Likos, W.J., 2006. Suction stress characteristic curve for unsaturated soil. Journal of geotechnical and geoenvironmental engineering, 132(2): 131-142.
Marchal, J., 1984. Renforcement des sols par clouage-étude expérimentale en laboratoire. In Renforcement en place des sols et des roches. Colloque international, 275-278.
Ng, C.W. and Pang, Y.W., 2000. Influence of stress state on soil-water characteristics and slope stability. Journal of geotechnical and geoenvironmental engineering, 126(2): 157-166.
Ning.L and William.L, Unsaturated Soil Mechanics, New York: John Wiley, 2004.
Sabhahit, N., Basudhar, P.K. and Madhav, M.R., 1995. A generalized procedure for the optimum design of nailed soil slopes. International journal for numerical and analytical methods in geomechanics, 19(6): 437-452.
Vanapalli, S.K., Fredlund, D.G. and Pufahl, D.E., 1999. The influence of soil structure and stress history on the soil–water characteristics of a compacted till. Geotechnique, 49(2): 143-159.
Van Genuchten, M.T., 1980. A closed‐form equation for predicting the hydraulic conductivity of unsaturated soils. Soil science society of America journal, 44(5): 892-898.
Scientific Quarterly Journal of Iranian Association of Engineering Geology
Volume 15, Issue 2
Summer 2022
Pages 1-17

  • Receive Date 07 January 2021
  • Revise Date 17 October 2021
  • Accept Date 07 January 2022