International Research Journal of Engineering and Technology (IRJET)
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STUDY OF BEHAVIOUR OF STONE REINFORCED COLUMN ON SOIL
Ankit Garg1, Ajay Singh2
1Research
Scholar, M. Tech. Structure and Construction Engineering, Roorkee Institute of Technology,
Roorkee, INDIA
2HOD, Structure and Construction Engineering, Roorkee Institute of Technology, Roorkee, INDIA
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ABSTRACT:- Rapid industrialization & huge level framework improvement Consequences in consumption of typical
helpful ground & it at the same time advances the utilization of peripheral & feeble dirt for foundation improvement. Stone
segments infer its heap conveying limit from the repression accessible by the encompassing dirt. In current examination,
we give two sorts of additional imprisonment remotely & inside & these are circumferential en-casement, roundabout
level strips & blend of two. Axis-symmetric investigations were completed utilizing Mohr-Coulomb's foundation taking
into account elasto- plastic conduct for delicate mud & stone. Three sort of encompassing are viewed as 8, 15, 31 kPa & the
heap conveying limit of footings situated over stone sections is contrasted & equivalent size of footings situated on the
virgin dirt that is without a stone segment underneath. Consequence demonstrates that as quality of encompassing dirt
expands impact of additional imprisonment diminishes.
Keyword: Bearing Capacity, Ground Improvement, Optimum strength, Stone Column.
1. INTRODUCTION
Because of the fast industrialization & substantial scale foundation advancement, there will be absence of helpful land.
When all is said in done practice, the development is done just on typical helpful land. The generally futile grounds like
metropolitan strong waste dump locales, destinations with marine dirt’s, compressible dirts or recovered terrains & so on
are currently deserving of development reason. Development on this sort of land is an experiment so ground improvement
procedures are favored because of efficient thought. It has been continually moving error to give protected & sound
establishments to structure with high loads & admissible fewer dispositions. The general practice is to improve the limit of
ground by distinct techniques, e.g., pre-pressure, vibration, compaction grouting, dynamic compaction, blast, woven
texture support & so forth. Currently days, stone sections [granular heaps] are effectively used to improve the craving
properties of the delicate dirt because of its viability & simplicity of establishment.
2. STONE COLUMN
Stone segment comprises coarse substance compressed in extensive round & hollow gap. Primary points of embeddings
pebble sections are to supplant the level of the delicate mud by rigid coarse substance so it might endure a heap of
construction. The whole soil underneath an establishment, in this way goes about strengthened dirt by means of superior
burden conveying limit then virgin dirt. Pebble section infers their heap conveying limit from the repression accessible by
the encompassing dirt. It is a ground improvement procedure used to improve the heap bearing limit & lessen the
disposition of the dirt. It is likewise called as granular sections or granular heaps. This system is otherwise called vibro
substitution. In this procedure thick total section [stone segments] is developed by techniques for a crane- suspended
down opening vibrator.
3. LITERATURE
Fundamental point of embeddings a stone segment is to supplant a level of the delicate mud with stiffer granular material
so it could endure the heap of the structure. Stone section determines its heap conveying limit from the confinement
accessible by the encompassing dirt. Stone segments having a more extended span than its basic span flops by swelling
independent that it is end bearing or gliding type [IS 2003]. There are four studies on stone column behaviora)
b)
c)
d)
Numerical & Analytical studies
TheoreticalStudies
Model ExperimentStudies
Prototype/ Field ExperimentStudies
In numerical & Analytical Studies An expository arrangement contemplated by Castro & Sagastea [2011] in which the
delicate dirt is managed as a versatile substance & the pebble segments as elasto plastic substance utilizing the MohrCoulomb replica with a steady expansion point.
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International Research Journal of Engineering and Technology (IRJET)
Volume: 06 Issue: 12 | Dec 2019
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e-ISSN: 2395-0056
p-ISSN: 2395-0072
An elasto plastic conduct is additionally considered for the circumferential en-casement. The outcome Consequences were
found in concurrence with mathematical investigation[1].
Ambily & Gandhi [2006] examined a genuine pressure power on the pebble segment & dirt utilizing F.E.M.A [PLAXIS].
Sand cushion are given at the surface to waste & the Influence of thickness of sand cushion on burden sharing b/w pebble
section & dirt are dissected by the examination for both inflexible & adaptable stacking condition [2].
In theoretical Studies a mechanical model played out by Deb et al. [2010] to anticipate the conduct of geo manufactured
strengthened coarse fill resting over delicate dirt. The improved gathering of pebble segments exposed to roundabout or
hub-symmetric stacking in which immersed delicate dirt, coarse fills, geo manufactured fortification & pebble section are
admired by spring dashpot framework, Pasternak shear layer, unpleasant flexible film & stiffer springs individually. The
mechanical model outcomes are contrasted &the research facility model experimentsConsequences[3].
The key note on the establishment technique, plan approach & distinctive disappointment techniques of stone sections
was demonstrated by Mokhtari & Kalantari [2012] [4].
In model Experimental studies Gandhi & Ambily [2007] played out a trial think about on conduct of single pebble section
& gathering of 7 pebble segments by changing the boundaries like dividing b/w the pebble segments, shearing quality of
delicate dirt & stacking condition. Limited E.A [PLAXIS2D] is additionally dissected utilizing 15noded-triangular
components & acquired outcomes are contrasted & the trialConsequences [5].
Murugesan & Rajagopal [2010] did the trial experiments on the subjective & quantitative improvement of burden
conveying limit of an en-cased pebble section. Burden experiment is done on single as well as gathering of stone segments
both with & without en-casement. What's more, extreme burden conveying limit of stone segments increments with
encasement was discovered. The addition in burden conveying limit relies upon encased substance modulus & pebble
segments breadth [6].
In field experimental studies Lee et al. [2008] contemplated the augmentation in a definitive burden limit & decrease in
swelling of a geogrid encased stone section utilizing field load experiments. It was seen from the field try that encased
stone sections have a lot higher burden conveying limit &lesser sidelong swelling contrasted with typical stonesegments
[7].
Poorooshasb & Meyerhof [1997] examined the effectiveness of general stone sections & lime segments in decrease in
disposition of delicate dirts. The impact of a few variables like segment separating, properties of dirt, & properties of stone
chips, in situ stress & the profundity of firm base from the tip of the section was considered [8].
4. MATERIAL & METHODOLOGY
4.1 Material Used
Six boundaries Modulus of Elasticity [E], Dry unit wt. [ γd], Poisson’s ratio [μ],edge of inner contact [φ], unit undrained
union [cu] & dilantancy edge [ψ] of an aggregate needed for Mohr-Coulomb examination. The info boundaries [E, µ, φ, ψ,
cu, γd] are given in Table 1 taken from Ambily & G&hi [2007]. In current examination, the water table has been set to be
toward the finish of the dirt store. The depleted conducts areexpected for every one of the resources. It is expected in this
investigation that in the wake of applying the heap & stress focus adequate time has passed & disposition has been
balancedout. Elasto-plastic continuum component, whose hub solidness is taken as the secant modulus, is displayed by the
geogrid acquired by the strain experiment. Elasto-plastic conduct of geogrid is characterized by the tractable modulus [EA]
of geogrid & the yield quality [Np]. Admired elasto-plastic conduct of geogrid is shown as specked line in Fig 1.
Table-1 Properties of material used
Material
W(%)
E (kPa)
M
cu (kPa)
Ψ (0)
Φ(0)
Clay
30
35
40
-
5600
3200
2250
55000
0.43
0.46
0.48
0.31
31
15
8
-
11
43
Stone
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γd
(KN/m3)
15.57
14.59
13.61
16.61
γsat (KN/m3)
19.46
18.99
18.37
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Fig 1- Tensile experiment on geogrid
5. Consequences & Discussion
Pebble sections determine their heap conveying limit from control accessible by encompassing dirt. En-casements of
pebble section have expanded utilization of pebble segments to delicate mud. A current examination contain pebble
segment by means of 3 sort of additional repression circumferential en-casement, roundabout flat tiles &mix of 2. An axissymmetric investigation was completed utilizing M.C model taking into account elastoplastic conduct for delicate mud &
pebble. 3 kind of encompassing are viewed as 8, 15, 31 kPa & the heap conveying limit of footings situated over pebble
segments is contrasted & equivalent extent of footings situated on the virgin dirt i.e.lacking a pebble segmentbottom.
5.1 Optimum Strength test
After breadth changing [measurement of stacking territory & distance proportion across pebble segment], the adjustment
in a definitive quality are watched for distinctive quality of keeping substance. Fig 2 demonstrates connection among the
breadth proportions to extreme quality for the diverse shear quality [cu = 8kPa, 15kPa & 31kPa] of keeping dirt. From the
figure, plainly there is a little improvement in extreme quality of stacked territory later distance across proportion of 5.
Fig-2 Diameter ratio & cu influence on optimum strength
6. Conclusion
The current task portrays a limited component examination completed to ponder the impact shear quality of dirt, width
proportion, outside fortification by assaulting the stone segment &inward support by giving even round strips on the
swelling conduct of stone segment & burden conveying limit. In view of the outcomes acquired from this examination the
accompanying ends are made:
For less quality of dirt [delicate dirt], as geo-grid en-casement span expands, a definitive quality of stone section
increments. In spite of the fact that, the rate of increment of extreme quality declines with expanded encasement span. In
any case, for excessive quality of dirt [solid dirt], fractional en-casement in top bit of pebble segments
areprogressivelysuccessful
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For delicate dirt, as number of flat round strips builds a definitive quality increments & discovered support over the full
section span gives higher extreme quality in any case, for firm dirt, fortification in upper locale is viable.
Mixture of outer fortification [circumferential encasement] & inward support [level round strips]is more compelling in
firm dirt instead of delicate dirt.
References
[1]
Castro, J. also, Sagaseta, C. (2011), Deformation and union around encased stone sections, Geotextile and
Geomembranes, vol.29, 268-276 [1].
[2]
Ambily, A. P. and Gandhi, S. R. (2006), Effect of Sand Pad Thickness On Load Sharing In Stone Column, Proceedings
of Indian Geotechnical Conference Dec 14- 16, 2006, Delhi, 555-556.
[3]
Deb, K., Basudhar, P.K., Chandra, S. (2010), Axi-symmetric Analysis of Geosynthetic-reinforced Granular Fill-soft
soil System with Group of stone Columns, Geotech Geol Eng, 28, 177-186.
[4]
Mokhtari, M. and Kalantari, B. (2012), Soft Soil Stabilization using Stone Columns- A Review, EJGE, vol.17, 14591466.
[5]
Ambily, A.P. what's more, Gandhi, S.R. (2007), Behaviour of Stone Columns Based on Experimental and FEM
Analysis, Journal of Geotechnical and Geoenvironmental Engineering, ASCE/APRIL 2007, 405-415 [2].
[6]
Murugesan, S. and Rajagopal, K. (2010), Studies on the behavior of single and group of geo synthetic encased stone
columns, Journal of Geotechnical and Geoenvironmental Engineering, ASCE, 129-138.
[7]
Lee, D., Yoo, C., Park, S., Jung, S. (2008), Field Load Tests of Geogrid Encased Stone Columns in Soft Ground,
Proceedings of the Eighteenth International Offshore and Polar Engineering Conference Vancouver, Canada, July
6-11, 521-524.
[8]
Poorooshasb, H.B. and Meyerhof, G.G. (1997), Analysis of behavior of stone columns and lime columns, Computers
and Geotechnics, vol-20, No-1, 47-70.
[9]
Deb-K, Dhar, A-Bhagat, [2012], development approach in support of ideal solidness investigation of geosyntheticstrengthened stone segment bolstered banks in mud, KSCE Journal of Civil Engineering, 16[7],1185-1192.
[10]
Deb-K, Dhar-A-Bhagat-P [2010] Analysis of Geosynthetic-strengthened Granular Fill-delicate dirt System with
Group of stone Columns, Geotech Geol Eng, 28, 177- 186.
[11]
Deb-K, Sama-dhiya, N-K, Nam-deo, J-B. [2011], Research center replica investigations on unreinforced & geogrid
fortified s& bed over stone section improved delicate dirt, Geotextile & Geomembranes, 29,190-196.
[12]
I.R, Ruji-kiatkamjorn, C. [2013], mathematical arrangement of stone segment improved delicate dirt thinking
about curving, stopping up & smear impacts, J. Geotech. Geoenviron. Eng., vol.139, 377-394.
[13]
M.V, S.N. what's more, Ilam-paruthi, K. [2008], mathematical Analysis of Encapsulated Stone Columns, The twelfth
International Conference of International Association for Computer Techniques & Advances in Geomechanics
[IACMAG],3719-3726.
Author profile
Mr. Ankit Garg received B.Tech. Degree in Civil Engineering from A.K.T.U in 2013. He is perusing M- Tech in Structure &
Construction Engineering from R.I.T Roorkee, (U.K). His areas of interest are Structure Design, Software Analysis regarding
to structure loads, Ground Improvement Techniques.
Prof. Ajay Singh working as an Assistant Professor at R.I.T Roorkee, (U.K). He has received his M-Tech in Structure
Engineering from BITS Pilani Rajasthan. His areas of interest are Structure Engineering, Soil Stabilizations, and Ground
Improvement Techniques.
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