A Numerical Study of Strip Footing with Granular Pile Anchor Build on Expansive Soils, Wad Medani City – Sudan

<span lang="EN-GB">Expansive soil is found in many parts of the world where its major drawback is its expansion and shrinking property upon moisture absorption and drying during alternation of rainy-dry seasons. Due to its swelling-shrinkage repeated process, fatigue and distress cause crack to structures. Granular pile anchor (GPA) system is a pioneering technique that is utilised in reinforcing these expansive soils. Granular pile anchor (GPA) system is a pioneering technique that is utilised in reinforcing expansive soils. The GPA provides tensile resistance which arrest the exerted upward forces and hence reducing heave. Previous investigations have only focused on load-displacement relationships by utilizing the pull-out technique. In this technique, an external force pulls the GPA and the corresponding displacements are recorded. The results provide indication of the GPA resistance to the applied force. However, in real conditions the heave and expansion forces were developed as a result of the pressure caused by the water absorption which pushes the entire soil bed in the upward direction along with the GPA. Therefore, this paper is aimed to explore this concept by carrying experimental and numerical investigations on a small scale model for a single pile with a diameter of 4 cm, with lengths of 20 and 40 cm. Ultimately, the reinforced soil exhibits reduction in upward force and heave compared to the unreinforced soil. Also, verifications for the testing shows that the relationship between the upward force and heave exhibits almost linear relationship for both experimental and numerical investigations. Therefore, shallow foundations incorporated with a GPA system proves to effectively lessen the heave that occurs in expansive soils which in turn can solve problems for constructions.</span>

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Comparative study on the behaviour of granular pile anchors and helical pile anchors in expansive soils subjected to swelling

International Journal of Geotechnical Engineering ◽

10.1080/19386362.2017.1398370 ◽

2017 ◽

Vol 14 (1) ◽

pp. 49-54 ◽

Cited By ~ 1

Author(s):

M. Muthukumar ◽

Sanjay Kumar Shukla

Keyword(s):

Comparative Study ◽

Expansive Soils ◽

Granular Pile

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Influence of Geogrid Reinforcement on Pullout Response of Granular Pile-Anchors (GPAs) in Expansive Soils

Indian Geotechnical Journal ◽

10.1007/s40098-016-0180-z ◽

2016 ◽

Vol 46 (4) ◽

pp. 437-444 ◽

Cited By ~ 9

Author(s):

B. R. Phanikumar

Keyword(s):

Expansive Soils ◽

Geogrid Reinforcement ◽

Granular Pile

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Numerical Study of Strip Footings Behavior on Compacted Sand

Journal of Engineering Research and Reports ◽

10.9734/jerr/2019/v5i316924 ◽

2019 ◽

pp. 1-10

Author(s):

Nasser A. A. Radwan ◽

Khaled M. M. Bahloul

Keyword(s):

Finite Element ◽

Bearing Capacity ◽

Layer Thickness ◽

Numerical Study ◽

Computer Software ◽

Strip Footing ◽

Loose Sand ◽

Strip Footings

The aim of this research is to investigate numerically the effect of using compacted sand as soil replacement layer beneath a strip footing on its bearing capacity. Finite element computer software Plaxis 2D version 8.6 was used to predict the behavior of strip footing resting on loose sand and on compacted sand. Study was conducted for footing widths of 1 up to 2 meters and various depths ranging from 1m up to 2m, also the effect of replacement layer thickness was investigated. It was found that using replacement layer beneath strip footing increases its bearing capacity for different widths and depths of footing. This improvement is observed up to thickness of replacement layer equal to 3 times the footing width (H/B=3), where further increase in replacement layer thickness does not affect significantly bearing capacity of footings.

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Increasing pull-out capacity of granular pile anchors in expansive soils using base geosynthetics

Canadian Geotechnical Journal ◽

10.1139/t00-012 ◽

2000 ◽

Vol 37 (4) ◽

pp. 870-881 ◽

Cited By ~ 21

Author(s):

B R. Phani Kumar ◽

N Ramachandra Rao

Keyword(s):

Expansive Soils ◽

Expansive Soil ◽

Swelling Pressure ◽

Ground Movement ◽

Anchor Plate ◽

Pull Out ◽

Swelling Soil ◽

Granular Pile ◽

Load Rate ◽

Uplift Load

Granular pile anchors are innovative and effective in resisting the uplift pressure exerted on the foundation by a swelling expansive soil. In a granular pile anchor, the foundation is anchored at the bottom of the granular pile to an anchor plate with the help of a mild steel rod. This renders the granular pile tension-resistant and enables it to offer resistance to the uplift force exerted on the foundation by the swelling soil. This resistance to uplift or pull-out load depends mainly upon the shear parameters of the pile-soil interface and the lateral swelling pressure of the soil, which confines the pile radially and prevents it from being uplifted. The resistance to uplift can be increased by placing a base geosynthetic above the anchor plate so that it forms an integral part of the granular pile anchor. The increase in resistance is due to the friction mobilized between the geosynthetic and the confining media when the uplift load acts on the pile and the geosynthetic moves along with the pile. Hence it depends on the friction between the geosynthetic and the confining media and the area and stiffness of the geosynthetic. This paper discusses the effects of these parameters on pull-out load, rate of heave, and relative ground movement near the pile surface.Key words: expansive soil, granular pile anchor, base geosynthetic, ground movement, rate of heave, pull-out load.

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