Journal Articles
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Item A Review on the Design, Applications and Numerical Modeling of Geocell Reinforced Soil(Springer Science and Business Media Deutschland GmbH, 2021) Vibhoosha, M.P.; Bhasi, A.; Nayak, S.For improving the stability and load carrying capacity of weak subgrade, strengthening methods are to be followed in the field. Among the various approaches, geocells have been identified as an effective soil reinforcement technique for improving soft subgrade behaviour. The three-dimensional honeycomb structure of geocell offers more lateral confinement to the infill soil resulting in improved load carrying capacity. This led to the widespread use of geocells for different geotechnical applications like pavements, foundations, embankments, slope protection, erosion control etc. Many researchers in the past have confirmed the suitability of geocell reinforcement through their experimental, numerical and field studies. In this paper, a comprehensive review of the reinforcement mechanisms, design aspect and numerical modelling techniques of geocell reinforced soil is provided. In addition, this paper highlights the various field application scenarios where different types of geocells have been used and explores the research challenges and scope for further research in this field. © 2021, The Author(s), under exclusive licence to Springer Nature Switzerland AG.Item 3-dimensional numerical modelling of sand bed reinforced with 3D geogrids of triangular form(Australian Geomechanics Society, 2019) Makkar, F.M.; Sreya, M.V.; Chandrakaran, S.; Sankar, N.In this paper, the bearing capacity improvement of a square footing resting on sand bed reinforced with 3D geogrids of triangular form is numerically studied with the help of Plaxis 3D software. The performance of 3D geogrid reinforced sand is also compared with planar geogrid reinforced sand to understand its effectiveness. In the numerical modelling, the soil behaviour is simulated by linear elastic-perfectly plastic Mohr-Coulomb model. The 3Dgeogrid and planar geogrid is modelled using geogrid structural elements available in the software. The model was validated with the experimental results and found to be in fairly good agreement with each other. The effect of various parameters on the behaviour of reinforced soil system was also investigated. It was found that the bearing capacity of multilayered planar geogrid reinforced sand bed improved by 3.68 times, while, the 3D geogrid reinforced sand bed shows 6.8 times improvement compared to the unreinforced sand bed. © 2019 Australian Geomechanics Society. All rights reserved.Item Comparative study on bearing capacity of bottom ash-stabilized soil mixed with natural and synthetic fibers(ASTM International service@astm.org, 2020) Prasannan, S.; Kolathayar, S.; Sharma, A.K.This article assesses the strength behavior of bottom ash (BA)-stabilized soil mixed with different fibers through a series of laboratory tests. Optimum BA and fiber percentage were obtained by small scale lab tests like compaction tests and unconfined compressive strength (UCS) tests. From compaction tests with varying proportions of BA (10, 20, 30, and 40 %), the optimum BA content was found to be 30 %. With this optimum BA content, UCS tests were conducted on soil-BA mix with different fibers (coir, areca, sisal, and polyvinyl alcohol) at various percentages (0.5, 1, 1.5, and 2 %) to find the optimum fiber content. A set of model footing tests were done to check the credibility of using fibers as a strengthening material beneath footing to upgrade the engineering properties of soil to make a reasonable subsoil for the foundation. A total of six model footing tests were performed on raw soil, on soil with optimum BA content, and on BA-stabilized soil mixed with different fibers in their optimum percentage (1.5 %). The bearing capacity of unstabilized unreinforced soil was found to increase significantly with the inclusion of fibers. © © 2020 by ASTM InternationalItem Performance of Footing on Clay Bed Reinforced with Coir Cell Networks(American Society of Civil Engineers (ASCE) onlinejls@asce.org 1801 Alexander Bell DriveGEO Reston VA 20191 Alabama, 2020) Kolathayar, S.; Narasimhan, S.; Kamaludeen, R.; Sitharam, T.G.Geocells are three-dimensional polymeric hexagonal pockets that provide lateral confinement to the soil, thereby increasing the bearing capacity of the soil bed. This paper briefly reviews past studies on geocell reinforcement of soil and presents a new product, cells made out of natural coir fiber, as an alternative to commercially available high-density polyethylene (HDPE) geocells. A series of model plate load tests were conducted on unreinforced soil and on soil reinforced with coir geocells to understand the soil reinforcement mechanism. It was observed that with the introduction of coir geocells, the load-bearing capacity of the soil bed increased up to three times and a significant reduction in the settlement was observed in the underlying weak soil bed. The study also presents a comparative performance evaluation of the natural coir cell-reinforced soil with conventional HDPE geocell-reinforced soil. Further, this paper analytically demonstrates the influence of the lateral resistance effect and vertical load dispersion effect incorporated by coir cells in strengthening the soil bed. © 2020 American Society of Civil Engineers.Item Study on Behaviour of Two Adjacent Strip Footings on Granular Bed Overlying Clay with a Void(Springer, 2020) Anaswara, S.; Shivashankar, R.This paper numerically examines the behaviour of two adjacent strip footings on granular bed over weak soil having a void. Voids could be formed in weak soil strata due to various reasons such as due to water leakage from the water supplying lines or sewer lines, poor drainage and erosion of soil, animal burrows, etc. A parametric study is carried out to understand the influence of granular bed thickness, width of footings, spacing between the footings, and the presence of a void beneath the footing in the weak soil, on the behaviour of footings. To understand the failure mechanism, shear strain contours, for different cases, are being studied. It is observed that there is a certain critical spacing between the two adjacent footings at which the footing/s carry the maximum load. This critical spacing depends on the type of loading, whether equal and simultaneous loading or unequal and sequential loading. The presence of voids also affects the performance of footings. Such voids tend to reduce the load carrying capacity of the footing/s and alter failure pattern. © 2020, Springer Science+Business Media, LLC, part of Springer Nature.Item Interference Studies of Adjacent Strip Footings on Unreinforced and Reinforced Sands(Springer, 2020) Anaswara, S.; Lakshmy, G.S.; Shivashankar, R.Interference effects of two and three strip footings placed adjacent to each other on unreinforced and reinforced sands are being studied in this paper. Effects on stresses in foundation soil, bearing capacity, settlements and tilts of footings are being looked into. Parameters varied in this study are (i) the number of footings (In the case of two footings loaded simultaneously, both experimental and numerical studies are conducted. In the case of two footings loaded sequentially and three footings, numerical studies are done.), (ii) loading conditions, (iii) clear spacing between the footings and (iv) number of reinforcement layers in foundation soil. With two footings, two loading conditions are considered. In the first loading condition, both footings are loaded simultaneously up to failure. In the second loading condition, one of the footings representing an already existing foundation is loaded with half of the estimated failure load of single strip footing and adjacent footing loaded up to failure. With two adjacent strip footings on unreinforced and reinforced sands, both loaded simultaneously, some laboratory-scale experimental studies are also conducted to compare with the numerical results. It is observed that there is a certain critical spacing at which the footing/s carry the maximum load. This critical spacing depends on the loading condition. Reinforcements in the foundation soil used are in the form of hexagonal wire meshes. The effect of providing the reinforcements in layers in the foundation soil is seen in the increased bearing capacity, reduced settlements and reduced tilts of the footings under simultaneous loading condition. Tilts are also found to be influenced by the loading condition. © 2020, Springer Science+Business Media, LLC, part of Springer Nature.Item Model Footing Tests and Analytical Studies on Clayey Soil Bed Reinforced with Coconut Shell Mat(Springer Science and Business Media Deutschland GmbH, 2022) Kolathayar, S.; Gadekari, R.S.The cellular confinement systems are becoming popular in ground improvement because of their efficiency in improving the bearing capacity of soil due to the lateral confinement effect. The commercially available geocells are made from polymer materials and they are costly. This study presents the performance evaluation of coconut shell mat as a cellular confinement system in clayey soil. It is the first of its kind application of coconut shells for soil reinforcement through a lateral confinement mechanism. This soil reinforcement system using coconut shells is termed “Geococoshell” by the authors. A series of model plate load tests were conducted on unreinforced soil, soil reinforced with High-Density Polyethylene (HDPE) geocells, and soil reinforced with coconut shell mats to evaluate the performance of coconut shell mat reinforced soil bed. The results of the experiments showed that coconut shells reinforced clayey soil improved bearing capacity up to 1.5 times compared to HDPE geocell reinforced clayey bed. The effect of different patterns of placing coconut shell mat was also studied and discussed in the paper. The analytical studies have been conducted considering the reinforcement mechanisms of coconut shell mat embedded in the soil bed. © 2022, The Author(s), under exclusive licence to Springer Nature Switzerland AG.Item Investigations on Bio-enzyme Stabilized Pavement Subgrades of Lateritic, Lithomargic and Blended Soils(Springer, 2023) Marathe, S.; Ravi Shankar, A.U.The pavement is a structure, which is laid to support the wheel load and to spread the load stress to a wider area on the top of the soil subgrade. The process of changing the engineering properties of natural soil, to improve its strength, bearing capacity and other engineering properties by the addition of suitable stabilizer and admixture is collectively known as stabilization of soil. It is very much essential to improve the soil strength, bearing capacity and other engineering properties to sustain the loads acting on the pavement. By modifying the subgrade soil properties, the crust thickness of the pavement reduces. This paper focuses on the effect of TerraZyme stabilization on three types of major soils available in the coastal Karnataka region. The study deals with the improvement in the engineering properties of these soils after subjecting to TerraZyme chemical stabilization. Initially, tests were carried out to study the mechanical properties like compaction, permeability, unconfined compressive strength (UCS) and California Bearing Ratio (CBR value). Further, the effect additions of TerraZyme chemical in various dosages to soil were observed in terms of their modified proctor compaction, UCS and CBR values. The curing effect on UCS and CBR was investigated. The structural design of pavement for the high-volume roads (as per IRC:37-2018) is proposed by strengthening the conventional subgrade soil layer with TerraZyme and the pavement analysis is carried out. © 2021, The Author(s), under exclusive licence to Chinese Society of Pavement Engineering.Item Performance Evaluation of Jute Geocell-Reinforced Sand Subgrade with an Integrated Wooden Anchor Grid(Springer Science and Business Media Deutschland GmbH, 2025) Kumar, P.; Kumar, D.H.; Bandyopadhyay, T.S.; Raveendran, D.; Kolathayar, S.; Mulangi, R.H.The efficient confinement capabilities of geocells make them a popular reinforcement technique for improving soil stability and load-bearing capacity. However, the high costs of synthetic geocells and environmental concerns have driven interest in more sustainable and natural alternatives. This study presents a novel approach to subgrade reinforcement using a jute geocell (JG) made from jute fabric, further improved with a wooden anchor grid (WAG). The newly developed jute geocell with wooden anchor grid (JGWAG) consists of a natural wooden grid integrated with anchor pins placed at the center of each JG pocket, aiming to enhance load-bearing capacity. The effectiveness of this innovative reinforcement system was evaluated through static plate load tests on sand subgrade reinforced with JG mattresses of varying widths (1.33D, 2D, and 3.33D, where D is the loading plate diameter) and a WAG placed beneath the 2D-width geocell. The results demonstrated significant performance enhancements: load-bearing capacity increased by 41%, 83.8%, and 116% for 1.33D, 2D, and 3.33D, respectively, compared to unreinforced subgrade. Notably, adding WAG under the 2D-width geocell achieved a remarkable 186% improvement over the unreinforced case. Settlement reduction was also significant, with the JGWAG system decreasing settlement by 84.6% as compared to the unreinforced case, showcasing its superior effectiveness. This system improves load-bearing performance and provides a cost-effective solution by reducing the width of JG. Furthermore, the surface roughness of the JG was analyzed using a 3D surface profilometer, ensuring optimal contact and friction between the soil and reinforcement for improved load transfer. © The Author(s), under exclusive licence to Springer Nature Switzerland AG 2025.