3D Numerical Stability Investigation of Sand Slope Reinforced Using Geogrid Encased Stone Column

Document Type : Research Article


1 Civil Engineering, Razi University, Kermanshah, Iran

2 Razi University


One of the efficient ways for reinforcing the earth’s slope is Geogrid Encased Stone Column (GESC). This technique can increase bearing capacity and decrease the settlement rate of the slope. The goal of this study is to perform a three-dimensional finite-difference numerical study on the behavior of GESC in the stabilization of sand slope. According to the results of the three-dimensional finite-difference analysis, the existence of GESC in the middle of the sand slope, as the optimal location for stone column placement, increased stability to an ideal level compared with the ordinary stone column (OSC). Different parameters including stone column diameter, coupling spring cohesion, coupling spring friction, center to center distance of columns (S/D ratio), and the layout of encasements were evaluated and discussed in this paper. The results indicated that the efficient parameter in geogrid is coupling spring cohesion; in which by increasing this parameter, slope bearing capacity increased linearly (i.e. the bearing capacity of slope reinforced using GESC could enhance up to 1.8 times of slope reinforced using OSC). In the case of row stone implementation, the maximum bearing capacity was that of S/D=2. However, a decrease in the S/D ratio did not necessarily increase the bearing capacity of slopes.


Main Subjects

[1] Abramson, L. W., Lee, T. , Sharma, S. , Boyce, G. (2002). Slope stability and stabilization methods. John Wiley & Sons, John Wiley & Sons.
[2] Almeida, S. S. a. M., M (2013). Design and Performance of Embankments on Very Soft Soils, Taylor and Francis.
[3] Hughes, J. M. O. a. W., N.J. (1974). “Reinforcing of soft cohesive soils with stone columns.” Ground Engineering 7(3): 42-49.
[4] Hughes, J. M. O. W., N.J. and Greenwood, D.A. (1975). “A field trial of the reinforcing effect of a stone column in soil.” Geotechnique 25(1): 31–44
[5] Madhav, M. R. a. V., P.P. (1978). “Strip footing on weak clay stabilized with a granular trench or pile.” Canadian Geotechnical Journal 15(4): 605–609
[6]  Aboshi, H. I., E. Harada, K. and Emoki, M. (1979). The composer—A method to improve the characteristics of soft clays by inclusion of large diameter sand columns. International Conference on Soil Reinforcement.
[7]  Barksdale, R. D. a. B., R.C. (1983). “Design and construction of stone columns.” Federal Highway Administration.
[8]  Ambily, A. P. G., S.R. (2007). “Behavior of stone columns based on experimental and FEM analysis.” Journal of Geotechnical and Geoenvironmental Engineering 133(4): 405–415.
[9]  Gueguin, M. H., G. and Buhan, P. (2015). “Stability analysis of homogenized stone column reinforced foundations using a numerical yeild desing approach.” Computers and Geotechnics 64: 10-19
[10] Castro, J. C., A. Costa, A. Ganizal, J. and Sagaseta, C. (2013). “Consolidation and deformation around stone columns: Comparison of theoretical and laboratory results.” Computers and Geotechnics 49: 326-337
[11] Han, J. a. Y., S.L. (2002). “A theoretical solution for consolidation rates of stone column-reinforced foundation accounting for smear and well resistance effects.” International Journal of Geomechanics 2(2): 135–151
[12] Adalier, K. E., A. Meneses, J. and Baez, J.I. (2003). “Stone columns as liquefaction countermeasure in non-plastic silty soils.” Soil Dynamics and Earthquake Engineering 23: 571–584
[13] Connor, S. S. G., A.G. (2000). A timely solution for the Nojoqi Grade landslide. Repair US 101 South of Buellton. 51st Annual highway geology symposium, Seattle.
[14] Christoulas, S. G., C. and Tsiambaos, G. (1997). “Stabilization of embankment foundations by using stone columns.” Geotechnical and Geological Engineering 15(3): 247–258
[15] Marandi, S. M. A., M. and Bahrami, M. (2016). “Uncertainty analysis of embankment built on stone column improved soft soil using fuzzy logic α-cut technique.” Computers and Geotechnics 75: 135-144.
[16] Madhav, M. R. a. M., N. (1994). Soil improvement panel report on stone columns. Proceedings of the 13th international conference on soil mechanics and foundation Engineering.
[17] Sanaeirad, A., and Jalalvandi, M. (2015). “Application of genetic algorithm for length design of reinforcement in reinforced soil slopes.” AmirKabir Journal of Science & Research Civil and Environmental Engineering (ASJR-CEE) 47(3): 53-60.
[18] Jafarian, Y., and Lashgari, A. (2017). “Effect of slip width on the permanent displacement of earth slopes.” AmirKabir Journal of Science & Research Civil and Environmental Engineering (ASJR-CEE) 49(1): 81-87.
[19] Salmasi, F. H. D., A. and Nourozi Sarkarabad, R. (2018). “Investigation of performance of horizontal drains in increasing slope stability in intense rain conditions by numerical simulation.” AmirKabir Journal of Science & Research Civil and Environmental Engineering (ASJR-CEE).
[20] McKenna, J. M. E., W.A. and Wolstenholme, D.R. (1975). “Performance of an embankment supported by stone columns in soft ground.” Geotechnique 25(1): 51–59
[21] Rathgeb, E. a. K., C. (1975). “Some applications of the vibro-replacement process.” Geotechnique 25(1): 45–50
[22] Datye, K. R. a. N., S.S. (1981). Design approach and field control for stone columns. Proc. of 10th Int. Conf. on SMFE, Stockholm.
[23] Bergado, D. T. P., B. Sampaco, C.L. and Miura, N. (1988). Reinforcement of soft Bangkok clay using granular piles. Int. Geotech. Symp. on Theory and Practice of Earth Reinforcement, Kyushu, Japan.
[24] Cooper, M. R. a. R., A.N. (1999). Stone column support for an embankment on deep alluvial soils. In Proceedings of the Institution of Civil Engineers, Geotechnical Engineering.
[25] Bergado, D. T. S., N. Sim, S.H. Panichayatum, B. Sampaco, C.L. Balasubramaniam, A.S. (1990). “Improvement of soft Bangkok clay using vertical geotextile band drains compared with granular piles.” Geotextiles and Geomembranes 9(3): 203–231
[26] Vekli, M. A., M. Ikizler, SB. and Calik, U. (2012). “Experimental and numerical investigation of slope stabilization by stone columns.” Natural Hazards 64: 797-820
[27] Zhang, C. J., G. Liu, X. and Buzzi, O, (2016). “Arching in geogrid-reinforced pile-supported embankments over silty clay of medium compressibility: Field data and analytical solution.” Computers and Geotechnics 77(11-25).
[28] Lai, H., J. Zheng, J.J. Zhang, J. Zhang, R.J. and Cui, L. (2014). “DEM analysis of “soil”-arching within geogrid-reinforced and unreinforced pile-supported embankments.” Computers and Geotechnics 61: 13-23
[29] Sharma, R. S. K., B.R.P. and Nagendra, G. (2004). “Compressive load response of granular piles reinforced with geogrids.” Canadian Geotechnical Journal 41(1): 187–192
[30] Gniel, J. a. B., A. (2009). “Improvement of soft soils using geogrid encased stone columns.” Geotextiles and Geomembranes 27: 167–175
[31] Fattah, M. Y. a. M. Q. G. (2012). “Finite Element Analysis of Geogrid Encased Stone Columns.” Geotechnical and Geological Engineering 30: 713–726
[32] Das, B. M. Advanced Soil Mechanics, Taylor and Francis.
[33] FLAC3D (Fast Lagrangian Analysis of Continua in 3 Dimension) user’s guide. Itasca Co.
[34] Khabbazian, M. M., C.L. and Kaliakin, V. (2014). “Column supported embankments with geosynthetic encased columns: Parametric study.” Transportation Infrastructure Geotechnology 1: 301-325
[35] Hajiazizi, M. Nasiri, M. and Mazaheri, A.R. (2018). “The Effect of Fixed Piles Tip on Stabilization of Earth Slopes.” Scientia Iranica 25(5): 2550-2560.
[36] Hajiazizi, M. a. N., M. (2018). “Experimental and Numerical comparison between reinforced earth slope using ordinary stone column and rigid stone column.” International Journal of Mining and GeoEngineering (IJMGE) 52(1): 23-30.
[37] Hajiazizi, M. a. N., M. (2016). “Experimental Studies of Cohesion Effect on Stability of Soil Slopes Reinforced with Stone Column.” Modares Civil Engineering Journal (M.C.E.J.) 16(5): 65-78.