Numerical investigation on factors for deep-seated slope stability of stone column-supported embankments over soft clay

Failure mechanism of geosynthetic-encased stone columns in soft soils under embankment

“…Three dimensional column-supported embankment can be converted into an equivalent plane strain problem using the column-wall method or the equivalent area method (Christoulas et al, 1997;Cooper and Rose, 1999;Tan et al, 2008;Abusharar and Han, 2011). Zhang et al (2014) compared the stability of an embankment reinforced with stone columns by using above two conversion techniques and found that, using the column-wall method normally gives lower factor of safety for short term stability, but for long term stability the results from the two methods are quite comparable. The main shortcoming of equivalent area method is that stress concentration near the columns cannot be simulated; therefore for short term stability, a reduction factor should be applied to the factor of safety obtained from equivalent area method as recommended by Zhang et al (2014).…”

“…Zhang et al (2014) compared the stability of an embankment reinforced with stone columns by using above two conversion techniques and found that, using the column-wall method normally gives lower factor of safety for short term stability, but for long term stability the results from the two methods are quite comparable. The main shortcoming of equivalent area method is that stress concentration near the columns cannot be simulated; therefore for short term stability, a reduction factor should be applied to the factor of safety obtained from equivalent area method as recommended by Zhang et al (2014). In the following analysis the reinforced soils were converted into column-walls using equivalent shear resistance method and equivalent bending resistance method.…”

“…The columns, such as sand compaction columns, stone columns, and deep mixed columns, can fail due to bending, sliding, rotation, shearing, tension, or a combination of the failure modes under embankment load (Kivelo and Broms, 1999;Han et al, 2005;Maruyama, 2006, 2007;Han, 2012;Zhang et al, 2014). Shear failure is the most common failure mode for sand compaction and stone columns (Abusharar and Han, 2011).…”

Three-dimensional numerical investigation on lateral movement and factor of safety of slopes stabilized with deep cement mixing column rows

“…Navin (2005), Adams (2011) andFilz et al (2012) suggested the use of overlapping column rows for a better interaction with the surrounding soft soil and studied the effect of the overlapping zone and strength in this zone. Abusharar and Han (2011) conducted a two-dimensional (2-D) numerical analysis on deep-seated slope stability of embankments over stone column-improved soft clay whereas Zhang et al (2014) conducted a three-dimensional (3-D) numerical analysis on the same problem. The results showed that factors of safety calculated by the equivalent area model were higher than those calculated by the individual column model in the 2-D numerical analysis.…”

Dynamic Characteristics of Saturated Silty Soil Ground Treated by Stone Column Composite Foundation

“…Stone column composite foundation (as shown in Figure 1), one of the most commonly used soil improvement technique, has been utilized worldwide to increase the bearing capacity of soft soils and reduce the settlement of superstructures constructed on them. Several researches have been carried out to study the behaviour of stone column-reinforced ground in recent years [2][3][4][5][6][7][8][9][10][11][12]. In these studies, stone columns are typically used in soft soils, as these cannot be compacted.…”