Analysis and comparison of displacement granular pile anchors

Madhav, M. R.; Vidyaranya, B.; Kumar, Venkata Sairam

doi:10.1680/grim.2008.161.1.31

Cited by 7 publications

(3 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A well-documented study on the GAP system has been carried out in the laboratory and field study before its application to actual field conditions [6][7][8][9][10]. The parametric analysis was performed to determine the ultimate pullout capacity of GAP in homogenous and non-homogenous soft ground [11,12]. A small-scale numerical analysis was performed on GAP in expansive soils [13,14].…”

Section: Introductionmentioning

confidence: 99%

Numerical Modeling of Granular Anchor Pile System in Loose Sandy Soil Subjected to Uplift Loading

Kranthikumar

Sawant

Shukla

2016

Int. J. of Geosynth. and Ground Eng.

View full text Add to dashboard Cite

During the last few decades various researchers have proposed appropriate experimental and numerical methods to estimate the uplift capacity of granular anchor piles (GAPs) in expansive soils. Surprisingly, very few studies have been performed to determine the uplift capacity of GAPs in loose sands. This paper presents the results of the numerical study to estimate the ultimate uplift capacity of group piles. Numerical analysis is performed using finite element software PLAXIS-3D. The foundation system is assumed to consist of a different number of regularly spaced GAPs installed in loose sandy soils. The analysis examines the influence of factors such as number of piles n and length L to width D ratio, and properties of the granular pile material and compares the efficiency of group of GAP systems of different configurations. Keywords Granular anchor pile Á Finite element method Á Loose sand Á Group piles Á Uplift capacity Notations L Length of a pile (m) D Diameter of a pile (m) c Total unit weight of soil above the water table (kN/m 3) c sat Saturated unit weight of soil (kN/m 3) / Angle of internal friction of soil (°) c Cohesion of soil (N/m 2) m Poisson's ratio E s Elastic modulus of surrounding soil (kPa) E p Elastic modulus of pile material (kPa) E Elastic modulus of plate element (kPa) d Thickness of a plate element (m) S Centre to centre spacing between piles in group piles (m) n Number of piles in a pile group g Efficiency & V. A.

show abstract

Section: Introductionmentioning

confidence: 99%

Numerical Modeling of Granular Anchor Pile System in Loose Sandy Soil Subjected to Uplift Loading

Kranthikumar

Sawant

Shukla

2016

Int. J. of Geosynth. and Ground Eng.

View full text Add to dashboard Cite

show abstract

“…Kumar et al (1997Kumar et al ( & 1999 and Ranjan et al (2000) present results from laboratory and field tests on pullout response of GPA in cohesive and cohesionless soils. A linear analysis of displacements of GPA is presented by Madhav et al (2008).…”

Section: Introductionmentioning

confidence: 99%

Group interaction analysis of displacements in granular pile anchors (GPA)

Vidyaranya¹,

Madhav²

2016

JGS Special Publication

Self Cite

View full text Add to dashboard Cite

Granular piles improve the behavior of the ground by increasing bearing capacity, reducing settlements, accelerating consolidation, and mitigating liquefaction related damages by reinforcement and densification effects. GPs due to their inherent nature can resist compressive and shear loads but not tensile ones. Granular piles can be made to resist pullout or uplift forces by placing an anchor at the base and attaching the same by a cable or rod to the footing to transfer the applied pullout forces to the bottom of the GP. Such an assembly is termed a Granular Pile Anchor (GPA). Analyses for displacements in granular pile anchors in groups of two, three or four, are presented based on Poulos and Davis (1980) for rigid piles. Results are presented as variations of interaction factor, 'α' with spacing s/d and relative stiffness factor, K. The results compare well with those of Poulos and Davis for rigid piles. The principle of superposition is validated for groups of 3 and 4 GPA.

show abstract

“…The effectiveness of this ground improvement technique is essentially controlled by the strength and stiffness of the soil confining the granular columns, particularly at shallow depths where the columns are prone to bulging. Phanikumar & Ramachandra Rao (2000), Phanikumar et al (2004), Liu et al (2006), Srirama Rao et al (2007), Madhav et al (2008), Phanikumar et al (2008) and Sivakumar et al (2013) looked at extending the applicability of this technique to resisting tension or pullout forces. These modified granular anchors consist of a base plate with a centrally located tendon (cable or metallic rod) encased in compacted granular backfill.…”

Section: Introductionmentioning

confidence: 99%

Granular anchors for stabilising slopes

Sivakumar

Lively²,

Solan

et al. 2014

Géotechnique Letters

View full text Add to dashboard Cite

A series of small-scale tests was undertaken to verify if granular anchors could be used as a slope stabilisation technique. The nature of the material used and the resulting loading configuration are described here. The work confirms that the inclusion of anchors within a slope mass, irrespective of their number or orientation, significantly enhances the capacity and ductility of the failure mode. The small-scale nature of this research did influence the observed capacities, but the overarching hypothesis was confirmed. A simple analysis method is proposed that allows designers to accurately remediate natural or man-made slopes using existing analytical methods for slope stability. (2008) and Sivakumar et al. (2013) looked at extending the applicability of this technique to resisting tension or pullout forces. These modified granular anchors consist of a base plate with a centrally located tendon (cable or metallic rod) encased in compacted granular backfill. The tendon is used to transmit the applied load to the column base via the circular base plate, which compresses the granular material to form the anchor. Under loading conditions, the bulging location of the granular anchor is at depth, where the strength and stiffness of the surrounding soil are significantly higher, thereby augmenting the capacity of the section. Sivakumar et al. (2013) examined the behaviour of granular anchors for a range of lengths (L) and diameters (D). This work concluded that the traditional bulging mechanism is the predominant mode of failure when the L/D ratio is greater than 5. The authors also carried out parallel studies on concrete anchors of similar L/D ratios and concluded that the capacity of both granular and concrete anchors were similar. However, the deformation responses of the granular anchors were more ductile, as opposed to the brittle failure mode of the concrete anchors.Granular anchors have been used to prevent uplift caused by flooding (Liu et al., 2006) and to resist heaving of foundations in expansive clays (Srirama Rao et al., 2007). This novel system could have much wider applications in the

show abstract

Analysis and comparison of displacement granular pile anchors

Cited by 7 publications

References 5 publications

Numerical Modeling of Granular Anchor Pile System in Loose Sandy Soil Subjected to Uplift Loading

Numerical Modeling of Granular Anchor Pile System in Loose Sandy Soil Subjected to Uplift Loading

Group interaction analysis of displacements in granular pile anchors (GPA)

Granular anchors for stabilising slopes

Contact Info

Product

Resources

About