Faculty Publications
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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 Slow release studies on commercial urea briquettes in loam and Silty clay soils of Karnataka, India(2011) Bhat, M.; Murthy, D.V.R.; Saidutta, M.B.In order to curtail losses of urea in wet agricultural soils, one of the cost effective method adopted is application of urea in large sized form such as briquettes. Commercially available pillow shaped uncoated urea briquettes and the briquettes modified by encapsulating them with kokum wax and paraffin wax coatings were subjected to release in two different soils of Karnataka viz. loam soil and silty clay soil. Results indicate that clay rich soil retarded dissolution of uncoated briquettes. Both kokum wax and paraffin wax coatings acted as good barriers for release of urea. These coatings were susceptible to rupture and release from the exposed areas. Kokum wax outperformed paraffin wax in all the soils. However, kokum wax coating was less stable in silty clay soil and the coating displayed higher shelf life in loam soil. Temperature accelerated the dissolution of both the uncoated as well as kokum coated briquettes in wet soil. © 2011 CAFET-INNOVA technical society. All right reserved.Item Investigating the Utility of Iron Ore Waste in Preparing Non-fired Bricks(Springer India sanjiv.goswami@springer.co.in, 2017) Lamani, S.R.; Mangalpady, M.; Vardhan, H.Iron ore waste is a major problem for mine owners due to the difficulty involved in its storage, handling and other environmental related issues. An alternative solution to this is utilisation of iron ore waste (IOW) as some value added product in construction industry. An attempt has been made in this paper in examining the possibility of making non-fired bricks from iron ore waste with some additives like cement and fly-ash. Each of the additives were mixed with IOW in different ratios and different sets of bricks were prepared. The prepared IOW bricks were cured for 7, 14, 21 and 28 days and their respective compressive strength and percentage of water absorption were determined. The results show that IOW bricks prepared with 9% and above cement and with 28 days of curing are suitable for brick making and meet the IS specifications. It was also observed that the weight of the prepared bricks with 9% cement with 28 days of curing varies between 2.35 and 2.45 kg whereas the weight of compressed fire clay bricks varies from 2.80 to 2.89 kg. Results also show that the cost of bricks prepared with cement ranging from 9 to 20% is comparable to that of commercially available compressed bricks. © 2016, The Institution of Engineers (India).Item A review on functional polymer-clay based nanocomposite membranes for treatment of water(Elsevier B.V., 2019) Buruga, K.; Song, H.; Shang, J.; Bolan, N.; Kalathi, J.T.; Kim, K.-H.Water is essential for every living being. Increasing population, mismanagement of water sources, urbanization, industrialization, globalization, and global warming have all contributed to the scarcity of fresh water sources and the growing demand of such resources. Securing and allocating sufficient water resources has thus become one of the current major global challenges. Membrane technology has dominated the field of water purification due to its ease of usage and fabrication with high efficiency. The development of novel membrane materials can hence play a central role in advancing the field of membrane technology. It is noted that polymer-clay nanocomposites have been used widely for treatment of waste water. Nonetheless, not much efforts have been put to functionalize their membranes to be selective for specific targets. This review was organized to offer better insights into various types of functional polymer and clays composite membranes developed for efficient treatment and purification of water/wastewater. Our discussion was extended further to evaluate the efficacy of membrane techniques employed in the water industry against major chemical (e.g., heavy metal, dye, and phenol) and biological contaminants (e.g., biofouling). © 2019 Elsevier B.V.Item Erosion Studies on Lithomargic Clays(Springer, 2020) Thomas, B.C.; Shivashankar, R.; Jacob, S.; Varghese, M.S.Lithomargic clays are found at shallow depths in lateritic formations, sandwiched between hard lateritic crust at top and the parent granitic gneiss underneath. Many earlier studies have proved that the behaviour of these soils is similar to dispersive soils, and they are also found to be highly erosive. Very few and detailed studies on erosion of lithomargic clays are available in the literature. Lithomargic clays along the western coastal belt of peninsular India are available with varying percentages of sands and fines (especially silts, with negligible amount of clays occasionally). In this study, a number of hole erosion tests are conducted on controlled lithomargic clay samples with varying percentage of fines to study their erosion characteristics. The influence of degree of compaction, moulding water content, head causing flow, percentage silt content and plasticity index on the erosion rate index and critical shear stress of controlled lithomargic clay samples are being studied. The results of this study indicate that the critical shear stress for soils with higher silt fraction and fine sand content varied from 45 to 125 N/m2, whereas for soils with higher clay fraction and fine sand content the critical shear stress varied from 200 to 400 N/m2. The erosion rate increased with a decrease in percentage compaction in all the samples, and critical shear stress is found to be highest at optimum moisture content conditions. It is generally observed that soils with fines whose plasticity indices are high, are less erodible compared to soils with fines whose plasticity indices are low. © 2019, Indian Geotechnical Society.Item Experimental Investigation and Performance Evaluation of Lithomargic Clay Stabilized with Granulated Blast Furnace Slag and Calcium Chloride(Springer Science and Business Media Deutschland GmbH, 2022) Lakkimsetti, B.; Nayak, S.South-western coast of India has vast deposits of highly problematic silty soil normally referred to as lithomargic clay in the literature. This problematic silty soil is characterized by its high sensitivity to moisture content with high erosion potential and low shear strength. This paper attempts to address this problem by chemical stabilization of lithomargic clay using Calcium chloride (CaCl2) and an industrial by-product obtained from the iron industry, i.e., granulated blast furnace slag (GBFS). Disposing of huge quantities of GBFS poses a severe impact on the environment. GBFS has high pozzolanic activity, and utilizing it for the stabilization of soils would be a sustainable and eco-friendly solution. To optimize CaCl2 and GBFS contents for achieving better geotechnical properties of the stabilized soil and to understand the mechanism governing the improvement, a series of laboratory experiments were performed on lithomargic clay by stabilizing it with different amounts of CaCl2 and GBFS. Optimum CaCl2 and GBFS contents obtained from the laboratory experiments are 6% and 20%, respectively, and a significant increase in strength was achieved with this optimized mix. Scanning electron microscope and X-ray diffraction analyses were carried out on the powdered samples of the treated soil, and the improvement in strength was justified through the microstructural changes observed due to the formation of cementitious compounds. Response of strip footings lying on unstabilized, and stabilized soils was analyzed using PLAXIS-2D. Numerical simulations showed a significant increase in the allowable bearing pressure with stabilization of lithomargic clay with GBFS and CaCl2. © 2022, The Author(s), under exclusive licence to Springer Nature Switzerland AG.Item Improving landfill liner performance with bentonite-slag blend permeated with ammonia for a Municipal solid waste landfill(Academic Press, 2024) Aswathy, A.; Sunil, B.M.Leachate emanating from landfills contains ammonia which may cause serious health effects on living things. An effectively designed clay barrier should not allow the contaminant to infiltrate the soil and groundwater systems. The utilization of certain industrial by-products in engineered landfill barriers, not only reduces the need for conventional liner materials but also helps in sustainable waste management. This study investigated the hydraulic conductivity, unconfined compressive strength, compaction, and adsorption characteristics of lithomargic clay blended with an optimum percentage of bentonite (10%) and granulated blast furnace slag (15%) permeated with ammonia. The results revealed that increasing the content of granulated blast furnace slag decreased the maximum dry density while increasing the optimum moisture content. In comparison to lithomargic clay, the hydraulic conductivity of the amended soil liner permeated with ammonia decreased from a value of 3 × 10−8 m/s to 5 × 10−10 m/s. The unconfined compressive strength of the amended soil specimens showed an increasing trend with curing times (i.e., 0, 14, 28, and 56 days). The batch adsorption results revealed that Freundlich and Langmuir's isotherm fits the equilibrium adsorption data and the adsorption of ammonia on clay liner follows non-linear behaviour. Overall, the experimental results implied that lithomargic clay blended with 10% bentonite and 15% granulated blast furnace slag can be used as an impermeable soil reactive barrier in engineered landfills. © 2024 Elsevier Ltd