Swelling behaviour of GPA-reinforced expansive clay beds subjected to swell-shrink cycles
TL;DR: Granular pile-anchor (GPA) technique has been found to be an innovative foundation technique for expansive clays posing the dual problem of swelling and shrinkage in this paper.
Abstract: Granular pile-anchor (GPA) technique has been found to be an innovative foundation technique for expansive clays posing the dual problem of swelling and shrinkage. Swelling occurs during absorption of water and shrinkage during evaporation of water. Generally, in field expansive clay beds, swelling takes place during rainy seasons and shrinkage during summers. GPA is a recent innovative foundation technique devised to ameliorate the dual swell-shrink problem of structures founded on expansive clay beds. The other innovative techniques are drilled piers, belled piers and under-reamed piles. Laboratory scale model studies and field scale experiments on GPAs yielded useful results and revealed that swelling of expansive clay beds was effectively controlled by GPA technique. Studies on swell-shrink behaviour of GPA-reinforced clay beds have not been performed so far. This paper presents results obtained from laboratory scale model studies on GPA-reinforced expansive clay beds subjected to alternate cycles of ...
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TL;DR: Zhang et al. as discussed by the authors investigated the relationship of factors that influence shale swelling, including initial water content, clay fraction, and confined pressure, and found that water adsorption creates higher swelling volume than moisture adsorptions.
126 citations
TL;DR: Several foundation techniques, such as belled piers, under-reamed piles, helical piles are adopted in expansive soils to avoid the problem posed by its swelling nature as mentioned in this paper.
Abstract: Several foundation techniques, such as belled piers, under-reamed piles, helical piles are adopted in expansive soils to avoid the problem posed by its swelling nature. In recent years, the granula...
18 citations
Additional excerpts
...Tests performed on laboratory-scale GPAs (Phanikumar and Muthukumar 2015) and field-scale GPAs (Rao et al. 2007) have (1)Pu = ps ( 4 D2f − 4 D2a ) (2)PR = Wa + 𝜋DaLa ( c� + ( K ?...
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TL;DR: Granular pile anchor (GPA) system is a simple and cost-effective foundation technique for resisting the uplift of foundation caused by swelling of expansive clay as discussed by the authors, which is used in the heave resu...
Abstract: Granular pile anchor (GPA) system is a simple and cost-effective foundation technique for resisting the uplift of foundation caused by swelling of expansive clay. This paper presents the heave resu...
11 citations
Cites background or result from "Swelling behaviour of GPA-reinforce..."
...Granular pile anchor (GPA) foundation is another foundation technique devised for controlling heave of expansive clay beds (Phanikumar et al. 2008; Phanikumar and Muthukumar 2015)....
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...This establishes the efficacy of GPA technique in reducing uplift of foundation caused by expansive clay beds upon saturation and agrees with previous research findings (Phanikumar and Muthukumar 2014, 2015)....
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TL;DR: In this article, an indoor physical model experiment of a ballastless track-subgrade filled with micro-expansive andesite at 1:2 scale was conducted to investigate the effects of the foundation swelling on the mechanical and deformation characteristics of the entire subgrade.
10 citations
References
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Book•
20 May 2004
TL;DR: Unsaturated Soil Mechanics as mentioned in this paper provides a comprehensive introduction to the fundamental principles of unsaturated soil mechanics and provides extensive sample problems with an accompanying solutions manual, and brings together the rapid advances in research in unsaturated soil mechanics in one focused volume.
Abstract: DESCRIPTION Unsaturated Soil Mechanics is the first book to provide a comprehensive introduction to the fundamental principles of unsaturated soil mechanics. * Offers extensive sample problems with an accompanying solutions manual. * Brings together the rapid advances in research in unsaturated soil mechanics in one focused volume. * Covers advances in effective stress and suction and hydraulic conductivity measurement.
940 citations
TL;DR: In this paper, a new elasto-plastic framework for unsaturated soils is proposed, involving coupling of hydraulic hysteresis and mechanical behaviour, and a specific constitutive model for isotropic stress states is proposed.
Abstract: Consideration of the different roles of pore air pressure, pore water pressure within bulk water and pore water pressure within meniscus water suggests that the degree of saturation will have a significant influence on the stress–strain behaviour of an unsaturated soil, in addition to any influence of suction. This suggestion is supported by experimental evidence. In the light of this, a new elasto-plastic framework for unsaturated soils is proposed, involving coupling of hydraulic hysteresis and mechanical behaviour. Within the proposed framework, plastic changes of degree of saturation influence the stress–strain behaviour, and plastic volumetric strains influence the water retention behaviour. A specific constitutive model for isotropic stress states is proposed, and model predictions are compared with experimental results, in order to demonstrate some of the capabilities of the new framework. Forms of behaviour that can be represented include proper transitions between saturated and unsaturated types ...
719 citations
"Swelling behaviour of GPA-reinforce..." refers background in this paper
...Expansive soils swell when they absorb water and shrink when water evaporates from them (Walsh et al. 1993, Wheeler et al. 2003, Lu and Lykos 2004)....
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Book•
01 Jul 1992
TL;DR: Expansive soils: problems and practice in foundation and pavement engineering as discussed by the authors, Expansive soil problems and practices in the field of pavement engineering and foundation and foundation engineering, etc.
Abstract: Expansive soils: problems and practice in foundation and pavement engineering , Expansive soils: problems and practice in foundation and pavement engineering , مرکز فناوری اطلاعات و اطلاع رسانی کشاورزی
673 citations
"Swelling behaviour of GPA-reinforce..." refers background in this paper
...Expansive soils are highly problematic as they have an inherent tendency to undergo volumetric changes corresponding to changes in moisture regime (Chen 1988, Nelson and Miller 1992)....
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TL;DR: In this article, the authors found abundant thaumasite, a complex calcium-silicate-hydroxide-sulfate-carbonate-hyd rate mineral, forming a solid solution series with ettringite.
Abstract: Expansive reactions between lime and sulfate-bearing clay soils have attracted little attention until relatively recently. Lime treatment of Stewart Avenue in Las Vegas, Nevada, had induced heave in excess of 12 in. Heaved areas are found to contain abundant thaumasite, a complex calcium-silicate-hydroxide-sulfate-carbonate-hyd rate mineral. Thaumasite forms a solid solution series with ettringite, a calcium-aluminum-hydroxide-sulfate-hy drate mineral. In the presence of aluminum, ettringite forms first and is replaced by thaumasite only at temperatures below 15°C. The mechanism of heave is a complex function of available water, the percentage of soil clay, and ion mobility. Only the long-term possolanic chemistry of normal lime-soil reactions is disrupted. Cation exchange, agglomeration, and carbonation are unaffected. With the present state of knowledge, lime-induced heave is difficult to predict for all but most obvious conditions.
365 citations
"Swelling behaviour of GPA-reinforce..." refers background in this paper
...…by non-expansive materials, artificial sandclay and gravel-clay mixes, chemical stabilisation using cement, lime, CaCl2 and fly ash (Petry and Little 1992, Hunter 1998, Rollings et al. 1999, Acosta et al. 2003, Hoyos et al. 2004, Phanikumar and Sharma 2004, Phanikumar 2009, Phanikumar et al. 2009)....
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TL;DR: In this paper, the effect of fly ash content on the free swell index, swell potential, swelling pressure, plasticity, compaction, strength, and hydraulic conductivity characteristics of expansive soil was evaluated.
Abstract: This note presents a study of the efficacy of fly ash as an additive in improving the engineering characteristics of expansive soils. An experimental program has evaluated the effect of the fly ash content on the free swell index, swell potential, swelling pressure, plasticity, compaction, strength, and hydraulic conductivity characteristics of expansive soil. The plasticity, hydraulic conductivity and swelling properties of the blends decreased and the dry unit weight and strength increased with an increase in fly ash content. The resistance to penetration of the blends increased significantly with an increase in fly ash content for a given water content. Excellent correlation was obtained between the measured and predicted undrained shear strengths.
348 citations
"Swelling behaviour of GPA-reinforce..." refers background in this paper
...…by non-expansive materials, artificial sandclay and gravel-clay mixes, chemical stabilisation using cement, lime, CaCl2 and fly ash (Petry and Little 1992, Hunter 1998, Rollings et al. 1999, Acosta et al. 2003, Hoyos et al. 2004, Phanikumar and Sharma 2004, Phanikumar 2009, Phanikumar et al. 2009)....
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