Conference Papers
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Item Numerical Analyses of Geogrid Reinforced Embankment Over Soft Clay(Springer Science and Business Media Deutschland GmbH, 2021) Keerthana, C.; Vibhoosha, M.P.; Bhasi, A.Construction of embankments on weak foundation soils is a challenging task for civil engineers due to excessive settlement, bearing capacity failure and slope stability issues. To solve this problem, a variety of ground improvement techniques, including vertical drains, grouting, complete soil replacement, geosynthetic reinforcement and piling, are adopted. Geosynthetics provides an alternative and economical solution and has been increasingly applied as reinforcement in embankments on soft soil. In the present study, 3D numerical analyses using the finite element program ABAQUS was carried out to study the time-dependent behaviour of geogrid reinforced embankment. Parametric studies were carried out by varying the height of the embankment. © 2021, Springer Nature Singapore Pte Ltd.Item A Numerical Study on Interference Effects of Closely Spaced Strip Footings on Cohesionless Soils(Springer Science and Business Media Deutschland GmbH, 2021) Anaswara, S.; Shivashankar, R.Foundations of buildings often need to be placed at close spacings to meet the various structural or functional requirements. In such cases, the combined action of adjacent footings is different from that of a single foundation. The combined effect causes interference of the stress zones. Numerical analysis is carried out on two closely spaced strip footings on sands, by varying the affecting parameters, to study the interference effects. Interference effects are analysed in terms of bearing pressure, settlement and tilt of foundations. In this study, the interference effects of closely spaced strip footings on the surface of cohesionless soils are being investigated. Parametric studies are done for two foundations by varying the clear spacing between the foundations. The results are presented in terms of interference factors. New structures near to the old construction may alter the settlement, pressure and rotational characteristics of the old footing and could lead to its distress. Above all, the load-carrying capacity of the new foundation will be very different from what it would have carried if it were independent—without the interference of the other footing. First footing representing an already existing footing is loaded with half of the estimated failure load of single independent strip footing and second adjacent footing loaded up to failure. The effect of interference of the old foundation is observed to be particularly significant in terms of the settlement and tilt. © 2021, Springer Nature Singapore Pte Ltd.Item Model Footing Tests on Sand Bed to Evaluate Efficiency of Tire Crumb as Infill Materials in Geocells(Springer Science and Business Media Deutschland GmbH, 2022) Kolathayar, S.; Chitrachedu, R.K.This paper presents the results of model footing tests on sand bed reinforced with HDPE and coir geocells. The infill material influences the performance of geocells. The potential of sand tire crumb (STC) mixture as infill material is evaluated in the study in comparison with pure sand as infill materials. To select the appropriate blend of sand and tire crumb, the shear properties and density properties were analyzed by performing direct shear and density tests. The mix which has shown the highest shear strength and density properties has been selected, and plate load tests were carried to analyze the mechanism and effectiveness of tire crumb as infill material in geocell pockets. From the results, it is clear that the sand tire crumb mix is effective as infill materials, especially for coir geocells. The surface heave was found to reduce significantly with sand tire crumb mix as infill material. © 2022, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.Item Seismic Responses of Rubble Mound Breakwater: Numerical Analyses(Springer Science and Business Media Deutschland GmbH, 2024) Akarsh, P.K.; Chaudhary, B.; Sajan, M.K.; Kumar, S.Rubble mound breakwater is a coastal structure, which is constructed to provide tranquil conditions in and around the port areas. Generally, the rubble mound structures are subjected to vigilant waves throughout the year. After the earthquakes of Kobe (1995), Kocaeli (1999), Tohoku (2011) etc. it is observed that the breakwaters can collapse due to failure of foundation and by seismic activity. Hence, in order to assess this problem, the current investigation deals with the study of rubble mound breakwaters and it is behavior against the seismic forces using numerical analysis. A finite element software PLAXIS is used for the numerical simulations. For study, a prototype has been selected and numerical model developed is a conventional rubble mound breakwater. In countermeasure model, the sheet piles in the foundation soil on extreme side of mound were considered. The numerical analyses have been done for constant seismic loading and soil properties. The parameters like vertical settlement and horizontal displacement were determined at different nodes. The vertical settlement was observed to be predominant in the crest region and it was reduced by 38% in countermeasure model. The displacement contours were significantly seen in core and armor units. The horizontal displacement of mound was seen by lateral movement of outer layers and it was 23% lesser for sheet pile reinforced model. © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2024.Item Comparison of Different Ground Improvement Techniques for the Road Construction Over Kuttanadu Clay Strata(Springer Science and Business Media Deutschland GmbH, 2024) Kumar, A.; Sreekantan, P.G.Kuttanadu clay is infamous for its very low shear strength and permeability. As a result, the construction of embankment over this stratum invites a lot of trouble including bearing capacity, settlement, and stability issues. To arrest these issues, proper ground improvement technique needs to be selected, which in turn is also governed by the construction cost, time, and practical feasibility. One such case study is the upgradation of Alappuzha-Changanassery road, where the height of the road level is proposed to be increased to tackle the issue of complete submergence during monsoon. In the present study, an attempt has been made to compare different ground improvement techniques in terms of stability, total settlement, and construction time. These techniques include prefabricated vertical drains (PVD) and lightweight filling using geofoam. The 1D consolidation and finite element analysis of these techniques were carried out using Midas Soilworks software, and the results were compared with the embankment construction without any ground improvement technique. The study inferred that the lightweight filling using geofoam blocks is the most efficient technique in terms of construction time, settlement, and stability. © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2024.Item A Critical Analysis of Curve Fitting Procedures Used in Evaluating Co-Efficient of Consolidation of Soils(Springer Science and Business Media Deutschland GmbH, 2025) Athira, S.; Sridhar, G.Consolidation settlement is the time-dependent phenomenon. Coefficient of consolidation is essential to estimate the rate of settlement of structures founded on saturated fine-grained soil. One of the common methods used to determine the coefficient of consolidation is through curve-fitting procedure. These procedures involve fitting a theoretical model to experimental data obtained from laboratory tests, such as the oedometer test. The Casagrande log t method and Taylor’s root t method are the standard methods to find the vertical coefficient of consolidation (cv). To design vertical drains, Barron’s theory is commonly used which requires coefficient of radial consolidation (cr). Over the past decade, several curve-fitting procedures namely the inflection method, rectangular hyperbola method, one-point method, early-stage log t method and many more, have been developed to determine either vertical or radial coefficients of consolidation. This paper provides a comprehensive review of procedures used for computing the vertical and radial coefficient of consolidation, offering a comparative analysis with advantages, limitations, and practical use of each method. Also, cv and cr of kaolin clay are determined through various methods. This assessment will be helpful to both academics and working engineers in accurately choosing the appropriate method for estimating the rate of settlement in saturated fine-grained soils. © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2025.Item Comparative Study of Settlement Performance of Stone Column and Vertical Drains: A Review(Springer Science and Business Media Deutschland GmbH, 2025) Kapile, P.; Sridhar, G.The process of building stone columns through weak soils, specifically soft and ultra-soft clays, is known as “vibro replacement.†An integrated foundation support system with reduced compressibility and enhanced load bearing capacity is formed by the stone column and the intervening soil. Stone columns in cohesive soils easily discharge excess pore water pressure, causing settlement to occur more rapidly than in clay without stone columns. Literature has shown that stone column has the tendency to bulge due to less in-situ lateral stress of soil which results in reduced effectiveness and increased settlement of stone column. Surcharging, a prevalent preloading method for strengthening weak ground, involves applying additional load through soil embankments. In the context of ground improvement, surcharge preloading is commonly used. Prefabricated vertical drains play a crucial role in expediting the consolidation process of soft clay deposits when employing preloading as a ground improvement technique. This paper presents a critical review of the settlement performance of stone column and preloading with prefabricated vertical drains as it is of utmost importance in ground improvement works. A case study comparing the settlement performance of stone column and preloading with prefabricated vertical drains revealed that latter technique is more suitable for extremely soft soil. © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2025.Item Numerical Study on Bearing Capacity Estimation of Circular Footing on Sand Reinforced with Sisal Geotextile(Springer Science and Business Media Deutschland GmbH, 2025) Jena, S.; Khatri, V.N.; Nainegali, L.This paper presents a study on estimating the bearing capacity of shallow circular footings on sand. In this regard, finite element analysis is conducted, assuming that the sand follows Bolton’s model with a relative density of 75%. Initially, the bearing capacity is determined for unreinforced sand conditions, followed by the placement of geotextile at different depths. The results indicate a significant increase in the ultimate bearing capacity of the footing, up to 2.68 times, compared to the unreinforced case, precisely when the geotextile is placed at a depth of 0.25 times the footing diameter. These findings suggest that sisal geotextile can effectively serve as a reinforcement material for addressing various temporary foundation-related problems. © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2025.