scholarly journals The influence of the rammed stone column formation on strength parameters of the surrounding soil

2014 ◽  
Author(s):  
Slawomir Kwiecien ◽  
Piotr Kanty ◽  
Jerzy Sekowski
Keyword(s):  
Stone Column ◽  
Strength Parameters ◽  
Column Formation ◽  
Surrounding Soil

Laboratory study on radial consolidation and deformation in clay reinforced with stone columns

2011 ◽  
Vol 48 (1) ◽  
pp. 36-52 ◽  
Author(s):  
Ana Cimentada ◽  
Almudena Da Costa ◽  
Jorge Cañizal ◽  
César Sagaseta
Keyword(s):  
Laboratory Tests ◽  
Load Transfer ◽  
Stone Columns ◽  
Stone Column ◽  
Column Diameter ◽  
Vertical Strain ◽  
Concentration Factors ◽  
Stress Concentration Factors ◽  
Horizontal Slice ◽  
Surrounding Soil

A series of laboratory tests was performed to study the deformation and radial consolidation around end-bearing (fully penetrating) stone columns. For this purpose, the behaviour of a horizontal slice of a unit cell representative of a column and the surrounding soil was analysed. The tests were carried out in a Rowe–Barden large oedometric cell that was instrumented to measure vertical stresses and pore pressures at several distances from the axis. Two column geometries were tested, with cell-to-column diameter ratios of N = 3 and 4. The most important findings of this work were the rate of pore pressure dissipation, the vertical strain reduction due to the presence of the column of approximately 25% for N = 4 and 35% for N = 3, and the load transfer to the column related to the stiffness ratio between the column and soil resulting in incremental stress concentration factors in the range 2.5 to 9.2. Results were compared with theoretical solutions that are commonly used for the study of stone column behaviour.

scholarly journals Numerical Study on Bearing Capacity and Bulging of the Composite Stone Column

2021 ◽  
Vol 15 (1) ◽  
pp. 13-28
Author(s):  
Mahmood A. Salam ◽  
Qiyao Wang
Keyword(s):  
Numerical Model ◽  
Bearing Capacity ◽  
Clay Soil ◽  
Confining Pressure ◽  
Stone Columns ◽  
Stone Column ◽  
Soil Stiffness ◽  
Preliminary Model ◽  
Concrete Part ◽  
Surrounding Soil

Background: In weak clay soil, a proper ground improvement technique using a stone column can be limited by the absence of sufficient lateral confining pressure. Stone columns should be strengthened to provide the minimum required lateral confining pressure. Objective: The aim of this study is to find out the significant improvement of the composite stone columns compared to the conventional stone columns by comparing the bearing capacity enhancement and the treated soil stiffness for both models. Composite stone columns with a solid concrete part at the top-head not only enhance the bearing capacity of the stone columns but also decrease the bulging failure and increase the surrounding soil stiffness. Methods: The 2D finite element analyses were carried out to simulate an experimental study conducted by Ambily and Gandhi on conventional stone columns. ABAQUS software program with the Mohr-Coulomb criterion for soft clay soil and stones was used in the simulation. First, a preliminary numerical model was created to simulate the experiment model. Similar material properties, boundary conditions, and constraints were considered in the preliminary model. The results were compared, and they were similar to the experimental results. During this process, the efficiency of the numerical model was confirmed. Second, the same numerical model was performed for the composite stone columns without modifying the material properties, boundary conditions, and constraints of the preliminary model. The parameters that influence the composite stone column bearing capacity as the length of the concrete part, the stress concentration ratio, and the shear strength of the surrounding soil, were all studied. Results: The data obtained from the aforesaid study was used along with ABAQUS software package. Compared to existing work, our approach achieves a significant correlation, and it indicates that the solid concrete part increases the surrounding soil stiffness, in addition to increasing the bearing capacity of the stone column. The solid concrete part resists bulging deformation by moving the bulging failure downward where the confining pressure is larger. The stress concentration ratio increases with the length of the solid concrete part. Conclusion: Composite stone columns have a significant influence on the improvement of weak clay soil and increase the bearing capacity of soil under superstructures. Furthermore, they also increase the stiffness of weak soil around the column. The magnitude of weak soil improvement by using composite stone columns is greater than conventional stone columns. Therefore, composite stone columns are more efficient and effective than conventional stone columns.

Nonlinear Consolidation Analysis of Stone Column Composite Ground under Time-Dependent Loading

2013 ◽  
Vol 353-356 ◽  
pp. 1106-1111
Author(s):  
Yan Ran Hu
Keyword(s):  
Permeability Coefficient ◽  
Separation Of Variables ◽  
Stone Column ◽  
Nonlinear Characteristic ◽  
Soil Variation ◽  
Consolidation Rate ◽  
Composite Ground ◽  
Consolidation Analysis ◽  
Nonlinear Consolidation ◽  
Surrounding Soil

A few solutions for stone column composite ground consolidation have been presented which ignoring the nonlinear characteristic of surrounding soil or the variation of upper load with time. Considering the nonlinear characteristic of surrounding soil, variation of upper load with time, distribution of permeability coefficient in smear zone, the governing equation for consolidation of composite ground is obtained. The equation is solved using separation of variables method. Finally, the influence of parameters on consolidation rate is discussed.

scholarly journals Stabilization of Kaolin Clay Soil Reinforced with Single Encapsulated 20mm Diameter Bottom Ash Column

2021 ◽  
Vol 930 (1) ◽  
pp. 012099
Author(s):  
M Hasan ◽  
M S I Zaini ◽  
N A A Hashim ◽  
A Wahab ◽  
K A Masri ◽  
...  
Keyword(s):  
Clay Soil ◽  
Ground Improvement ◽  
Soft Clay ◽  
Bottom Ash ◽  
Stone Column ◽  
Unconfined Compression ◽  
Strength Parameters ◽  
Unconfined Compression Test ◽  
Materials Used ◽  
Compaction Method

Abstract Ground improvement methods are used to reduce the weakness of soft clay, which is low strength and high compressibility. The stone column technique involves replacing any of the soil with crushed stone such as broken rocks or sand which is an efficient method of improving the strength parameters of soil. Bottom ash usage in materials of building will effectively decrease the buildup of the waste and hence protect the environment. This study is to determine the shear strength of kaolin soft clay reinforced with a 20 mm diameter single encapsulated bottom ash column with various lengths. The research will look into the physicomechanical qualities of the materials used, including subsoil and bottom ash. Three (3) batches of samples with each batch consists of five (5) samples were prepared by using compaction method. All kaolin samples with a diameter of 50mm and height of 100mm with single encapsulated bottom ash columns with various lengths which are 60mm, 80mm, and 100mm were tested under Unconfined Compression Test (UCT). The result illustrated that the strength of samples increases as the height and volume of encapsulated bottom ash column increases.

DEFORMATION MODULUS AND STRENGTH PARAMETERS OF SABALOKA IGNEOUS ROCK MASS

2010 ◽  
Vol 33 (2) ◽  
pp. 153-158
Author(s):  
Mohamed Hassan Aboud ◽  
Mohamed Ahmad Osman
Keyword(s):  
Rock Mass ◽  
Igneous Rock ◽  
Deformation Modulus ◽  
Strength Parameters
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