Ground Improvement by Using Floating Granular Piles: Experimental Studies and Numerical Investigations

2022 ◽  
pp. 465-475
Author(s):  
Murtaza Hasan ◽  
N. K. Samadhiya
Keyword(s):  
Ground Improvement ◽  
Experimental Studies ◽  
Numerical Investigations ◽  
Granular Piles

scholarly journals Ground improvement using granular pile anchor system: resistance to heave and uplift pressure

2020 ◽  
Vol 19 (1) ◽  
pp. 403
Author(s):  
Alvin John Lim Meng Siang ◽  
Ehab Hamad Sfoog ◽  
Nahla Naji ◽  
Sim Sy Yi ◽  
Nickholas Anting Anak Guntor ◽  
...  
Keyword(s):  
Moisture Absorption ◽  
Expansive Soils ◽  
Ground Improvement ◽  
Reinforced Soil ◽  
Scale Model ◽  
Small Scale ◽  
Numerical Investigations ◽  
Anchor System ◽  
Pull Out ◽  
Granular Pile

<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>

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.

Mitigation of Liquefaction Hazard Using Granular Piles

2011 ◽  
Vol 2 (1) ◽  
pp. 44-66 ◽  
Author(s):  
A. Murali Krishna
Keyword(s):  
Ground Improvement ◽  
Stone Columns ◽  
Loose Sand ◽  
Short Discussion ◽  
Remedial Measure ◽  
Design Concepts ◽  
Liquefaction Mitigation ◽  
Liquefaction Hazard ◽  
Granular Piles ◽  
Surrounding Soil

In this paper, ground improvement techniques are used to mitigate liquefaction hazards. Granular piles are the preferred alternative due to several advantages. Granular piles improve the ground by reinforcing and adding density to the surrounding soil apart from providing drainage. Different mechanisms operate in the function of stone columns/granular piles in liquefaction mitigation, including Drainage, Storage, Dilation, Densification, and Reinforcement. This paper presents an overview of the use of granular piles as a liquefaction remedial measure for sand deposits. A brief description on liquefaction and the associated features is presented. A short discussion on various ground improvement methods available for liquefaction mitigation is discussed in light of the importance of granular piles. Different installation methods and design concepts for granular piles are presented. Various mechanisms of granular piles in mitigating the liquefaction potential of loose sand deposits are discussed and quantified in detail proving their effectiveness in hazard mitigation.

scholarly journals Behavior of Pervious Concrete Pile based on Vertical Loading

2021 ◽  
Vol 9 (VII) ◽  
pp. 3884-3891
Author(s):  
Avinash A Rakh
Keyword(s):  
Ground Improvement ◽  
The United States ◽  
Pervious Concrete ◽  
Water Runoff ◽  
Vertical Load ◽  
Concrete Piles ◽  
Concrete Pile ◽  
Improvement Method ◽  
Granular Piles ◽  
Surrounding Soil

Permeable granular piles are used to increase the time rate of consolidation, reduce liquefaction potential, improve bearing capacity, and reduce settlement. However, the behaviour of granular piles depends on the confinement provided by surrounding soil, which limits their use in very soft clays and silts, and organic and peat soils. This research effort aims to develop a new ground-improvement method using pervious concrete piles. Pervious concrete piles provide higher stiffness and strength, which are independent of surrounding soil confinement, while offering permeability comparable to granular piles. This proposed ground-improvement method can improve the performance of different structures supported on poor soils. To achieve the goal of the research project, a series of pervious concrete sample mixing has been conducted to investigate the pervious concrete material properties. Laboratory tests are carried out on a pervious concrete pile of 100 mm diameter and variation at different lengths (500mm,400mm,300mm) surrounded by sand of different density. The tests are carried out either with an entire equivalent area loaded to estimate the stiffness of improved ground or only a column loaded to estimate the limiting axial capacity. Pervious concrete is a special concrete product made primarily of a single-sized aggregate. Pervious concrete has been used in pavements to reduce storm-water-runoff quantities and perform initial water-quality treatment by allowing water to penetrate through the surface. In the United States, pervious concrete is mainly used in pavement applications, including sidewalks, parking lots, tennis courts, pervious base layers under heavy-duty pavements, and low traffic-density areas. The vertical load responses of pervious concrete are the variation of soil stresses and displacement are discussed. Nine tests are conducted on pervious concrete pile further investigate the behaviour of the pervious concrete pile and surrounding soil under vertical load condition. Therefore, Pervious Concrete Piles is particularly suitable for reinforcing subsoil that has low strength and poor permeability.

scholarly journals An Analytical Study of Partially Strengthened Single End-Bearing Granular Pile Near the Top and Bottom

2021 ◽  
Vol 43 (2) ◽  
pp. 99-115
Author(s):  
Vaibhaw Garg ◽  
Jitendra Kumar Sharma ◽  
Ashish Solanki
Keyword(s):  
Shear Stress ◽  
Analytical Study ◽  
Ground Improvement ◽  
Stone Columns ◽  
Feature Analysis ◽  
Granular Pile ◽  
Granular Piles

Abstract Stone columns (or granular piles, GPs) are progressively being utilized for ground improvement, mostly for pliant edifice such as road mounds, oil depot, and so forth. The present analysis is done by introducing strengthening at both the ends of GP, i.e., bottom and top end so that the bulging problem will be solved and the beneficiary effect of the bearing stratum can be utilized by the bottom strengthening feature. Analysis of a single partially strengthened, at both top and bottom, end-bearing GP is presented in this article in terms of displacement affecting component for the top (DACT) of GP, percentage load transferred to the base (PLTB) of strengthened GP, and normalized shear stress (NSS). The PLTB of the strengthened GP was found to increase considerably. The NSS was found to reduce at the top end of GP and is found to be redistributed along the length of GP.

Mitigation of Liquefaction Hazard Using Granular Piles

2018 ◽  
pp. 86-116
Author(s):  
A. Murali Krishna
Keyword(s):  
Ground Improvement ◽  
Stone Columns ◽  
Loose Sand ◽  
Short Discussion ◽  
Liquefaction Potential ◽  
Design Concepts ◽  
Liquefaction Mitigation ◽  
Liquefaction Hazard ◽  
The World ◽  
Granular Piles

Ground improvement techniques are employed to mitigate liquefaction hazards. Granular piles are the most widely preferred alternative all over the world, due to several advantages associated with them. Different mechanisms operate in the function of stone columns/granular piles in liquefaction mitigation like drainage, storage, dilation, densification, and reinforcement. This chapter presents an overview of the use of granular piles as a liquefaction remedial measure for sand deposits. A brief description on the phenomenon of liquefaction and the associated features has been presented. A short discussion on various ground improvement methods available for liquefaction mitigation is presented in light of importance of granular piles. Different installation methods and design concepts for granular piles are presented. Various mechanisms of granular piles in mitigating the liquefaction potential of loose sand deposits are discussed and quantified in detail proving their effectiveness in hazard mitigation.

scholarly journals Experimental and Numerical Studies on Setback Buildings Considering the SSI Effect under Seismic Response

2021 ◽  
Vol 7 (3) ◽  
pp. 431-448
Author(s):  
R. M. Thejaswini ◽  
L. Govindaraju ◽  
V. Devaraj
Keyword(s):  
Seismic Response ◽  
Scaling Laws ◽  
Experimental Studies ◽  
Soil Conditions ◽  
Dynamic Scaling ◽  
Seismic Behaviour ◽  
Resonant Frequencies ◽  
Numerical Investigations ◽  
Irregularity Index ◽  
Comparison Of The Results

From the previous studies it is observed that due to the effect of the earthquake, several irregular buildings failed vulnerably. Further the effect of sub soil conditions where these buildings have been founded also play an important role on the seismic response of these buildings. In the past, experimental studies on the seismic response of different setback building configurations have not been carried out. Therefore, in the present study the seismic behaviour of setback buildings considering Soil Structure Interaction (SSI) has been evaluated by conducting experimental and numerical investigations. Buildings with various setback configurations were considered and are designed as pile foundation supported structures. The irregularity index of these building configurations have been determined as per the existing codal provisions. These piles supported buildings representing the prototype structure have been scaled down according to geometric, kinematic and dynamic scaling laws. The scaled building models are subjected to vibrations beyond resonant frequencies using shake table facility. A comparison of the results has been made between experimental and numerical investigations. Based on the study it has been observed that storey displacements of building with regular configurations are higher in comparison with the setback buildings. It is also found that asymmetrical and symmetrical setback buildings having different irregularity indices as per IS:1893-2016 indicate nearly the same displacements at resonant frequencies. Doi: 10.28991/cej-2021-03091664 Full Text: PDF

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