Ground improvement of clayey soil formations using stone columns: A case study from Greece

2009 ◽  
Vol 3 (4) ◽  
pp. 493-498 ◽  
Author(s):  
Haralambos Saroglou ◽  
Andreas Antoniou ◽  
Spyros Pateras
Keyword(s):  
Clayey Soil ◽  
Ground Improvement ◽  
Stone Columns

scholarly journals Comparison between unit cell and plane strain models of stone column ground improvement

2018 ◽  
Vol 7 (2) ◽  
pp. 263
Author(s):  
Maryam Gaber ◽  
Anuar Kasa ◽  
Norinah Abdul Rahman ◽  
Jamal Alsharef
Keyword(s):  
Stress Concentration ◽  
Plane Strain ◽  
Clayey Soil ◽  
Cell Model ◽  
Ground Improvement ◽  
Soft Soil ◽  
Unit Cell ◽  
Stone Columns ◽  
Stone Column ◽  
The Impact

This article presents a comparative study of the behaviour of clayey soil reinforcements using stone column ground improvement by means of numerical analyses. Two-dimensional finite element analyses with commercially available software, PLAXIS, were performed on end-bearing stone columns using 15-noded triangular elements to investigate the impact of the modelling type on the stress concentration ratio and failure mechanism of an improved foundation system. Consolidation analyses were conducted throughout the study using Mohr-Coulomb’s criterion. The computed values of the stress concentration ratios were compared for different key parameters, including the diameters of stone columns, c/c spacing of columns, friction angle of stone column material, and undrained cohesion of soft soil. The major conclusions of this study were that the stone column in the unit cell model shared between 2.5 to 3.14 times more loads than the surrounding soil, whilst in the plane strain model it shared between 1.7 to 2.9 times more loads. The use of plane strain approach to model the stone column gave a more comprehensive representation of the stress distribution and load transfer between the soil and columns, in addition to being a better method than the unit cell concept to evaluate the failure mode in this system.

Prediction of the Effect of Using Stone Column in Clayey Soil on the Behavior of Circular Footing by ANN Model

2018 ◽  
Vol 24 (5) ◽  
pp. 86
Author(s):  
Omar Khaleel Ismael Al-Kubaisi
Keyword(s):  
Clayey Soil ◽  
Ground Improvement ◽  
Bending Moment ◽  
Horizontal Stress ◽  
Soil Strength ◽  
Stone Columns ◽  
Stone Column ◽  
Soil Consolidation ◽  
Ann Model ◽  
Circular Footing

Shallow foundations are usually used for structures with light to moderate loads where the soil underneath can carry them. In some cases, soil strength and/or other properties are not adequate and require improvement using one of the ground improvement techniques. Stone column is one of the common improvement techniques in which a column of stone is installed vertically in clayey soils. Stone columns are usually used to increase soil strength and to accelerate soil consolidation by acting as vertical drains. Many researches have been done to estimate the behavior of the improved soil. However, none of them considered the effect of stone column geometry on the behavior of the circular footing. In this research, finite element models have been conducted to evaluate the behavior of a circular footing with different stone column configurations. Moreover, an Artificial Neural Network (ANN) model has been generated for predicting these effects. The results showed a reduction in the bending moment, the settlement, and the vertical stresses with the increment of the stone column length, while both the horizontal stress and the shear force were increased. ANN model showed a good relationship between the predicted and the calculated results.  

scholarly journals Geotechnical properties of reinforced clayey soil using nylons carry’s bags by products

2018 ◽  
Vol 162 ◽  
pp. 01020 ◽  
Author(s):  
Nahla Salim ◽  
Kawther Al-Soudany ◽  
Nora Jajjawi
Keyword(s):  
Soil Stabilization ◽  
Clayey Soil ◽  
Ground Improvement ◽  
Soft Soil ◽  
Liquid Limit ◽  
Waste Material ◽  
Industrial Wastes ◽  
Dry Density ◽  
Maximum Dry Density ◽  
Replacement Technique

All structures built on soft soil may experience uncontrollable settlement and critical bearing capacity. This may not meet the design requirements for the geotechnical engineer. Soil stabilization is the change of these undesirable properties in order to meet the requirements. Traditional methods of stabilizing or through in-situ ground improvement such as compaction or replacement technique is usually costly. Now a safe and economic disposal of industrial wastes and development of economically feasible ground improvement techniques are the important challenges being faced by the engineering community. This work focuses on improving the soft soil brought from Baghdad by utilizing the local waste material for stabilization of soil, such as by using “Nylon carry bag’s by product” with the different percentage and corresponding to 1 %, 3% and 5% (the portion of stabilizer matters to soil net weight) of dried soil. The results indicated that as Nylon’s fiber content increases, the liquid limit decreases while the plastic limit increases, so the plasticity index decreases. Furthermore, the maximum dry density decreases while, the optimum moisture content increases as the Nylon’s fiber percentage increases. The compression index (decreases as the Nylon’s fiber increases and provides a maximum of 43% reduction by adding 5% nylon waste material. In addition, the results indicated that, the undrained shear strength increases as the nylon fiber increases.

scholarly journals Analysis and settlement evaluation of an end-bearing granular pile with non-linear deformation modulus

2018 ◽  
Vol 40 (3) ◽  
pp. 188-201 ◽  
Author(s):  
Jitendra Kumar Sharma ◽  
Pooja Gupta
Keyword(s):  
Influence Factor ◽  
Ground Improvement ◽  
Deformation Modulus ◽  
Relative Length ◽  
Stone Columns ◽  
Linear Deformation ◽  
Dense Sand ◽  
Granular Pile ◽  
Non Linear ◽  
Granular Piles

AbstractGround improvement with granular piles increases the load-carrying capacity, reduces the settlement of foundations built on the reinforced ground and is also a good alternative to concrete pile. Granular piles or stone columns are composed of granular material, such as crushed stone or coarse dense sand. An analytical approach based on the continuum approach is presented for the non-linear behaviour of the granular pile. The formulation for pile element displacement is done considering the non-homogeneity of the granular pile as it reflects the true behaviour and also accounts for the changes in the state of the granular pile due to installation, stiffening and improvement effects. The present study shows that the settlement influence factor for an end-bearing granular pile decreases with increase in the relative stiffness of the bearing stratum. The settlement influence factor decreases with increase in linear and non-linear non-homogeneity parameters for all values of relative length. For a shorter pile, the rate of decrease of the settlement influence factor is greater in comparison to that for a longer pile. Shear stress at the soil–granular pile interface reduces in the upper compressible portion of the granular pile and increases in the lower stiffer portion of the granular pile due to the non-homogeneity of an end-bearing granular pile.

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