Numerical modeling of geosynthetic-encased stone column-reinforced ground

Abstract

This paper presents the results of a comparative study on different finite element modeling approaches for modeling geosynthetic-encased stone column-reinforced ground for use in rapid embankment construction. The specific models considered include: (1) an axisymmetric unit cell; (2) a three-dimensional (3D) column; and (3) a full 3D model. The validity of the unit cell model was tested by comparison with the results from the 3D models. The applicability of continuum elements for modeling the geosynthetic encasement was also investigated. The results show that the 3D column model yielded practically identical results when compared with those of the full 3D model whereas the two-dimensional axisymmetric unit cell model tended to yield results that were 10 to 20% larger in terms of the vertical effective stress and lateral deformation of the stone column. It is also shown that a layer(s) of continuum elements can be used to model the geosynthetic encasement instead of membrane elements which are not readily available in commercial software for geotechnical analysis, provided that the axial stiffness of the geosynthetic encasement is taken into consideration. Based on the results of analysis, the effect of geosynthetic encasement on the performance of stone columns installed in soft ground under embankment loading is also discussed.

Reinforced granular column for deep soil stabilization: A review

“…It was concluded that effect of angle of internal friction and elastic modulus of stone column material was negligible on load carrying capacity of stone In the 3D numerical analysis done by Yoo and Kim (2009), it was observed that with encased stone column pore pressure developed was 3 times lesser than ordinary stone column. Murugesan and Rajagopal (2006) concluded that the encasement beyond depth equal to twice the diameter of the column does not lead to further improvement in performance.…”

“…Murugesan and Rajagopal (2006) concluded that the encasement beyond depth equal to twice the diameter of the column does not lead to further improvement in performance. The report of Yoo (2009), suggests that the different encasement depths should be adopted for different loading condition i.e. short and long term.…”

Laboratory Experimental Analysis on Encapsulated Stone Column

“…Numerical studies on geosynthetic encapsulated stone columns have been carried out by KHABBAZIAN et al [13], LO et al [14], MURUGESAN and RAJAGOPAL [15], PULKO et al [16], YOO and KIM [17] and ZHANG et al [18], RAITHEL and KEMPFERT [19], WU et al [20], among others.…”

Construction of geogrid encased stone columns: A new proposal based on laboratory testing

“…To provide a more robust and perhaps stiffer alternative to geotextile and to broaden the appeal of geosynthetics in stone column ground improvement, the use of geogrid encasement has recently been investigated (Trunk et al, 2004;Heerten and Ewert, 2004;Malarvizhi and Ilamparuthi, 2007;Rajagopal, 2007, 2009;Yoo and Kim, 2009;Gniel and Bouazza, 2009). Trunk et al (2004) reported on unconfined compression testing of stone aggregate columns measuring 1.88 m in height and 0.6 m in diameter.…”