Faculty Publications
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Item Geotechnical characteristics of lithomargic clay blended with marine clay as landfill liner material(CAFET INNOVA Technical Society cafetinnova@gmail.com 1-2-18/103, Mohini Mansion, Gagan Mahal Road, Domalguda, Hyderabad 500029, 2012) Allamaprabhu, K.; Sunil, B.M.; Nayak, S.; Fernandes, S.; Zafar, M.This paper reports a series of laboratory tests conducted on lithomargic clay (shedi soil), which is widespread over part of southwest coast of India, to assess whether it could be used as compacted clay liner for hydraulic barriers in engineered landfill. In order to assess the suitability of lithomarge as a barrier material, following tests such as index properties, compaction characteristics, hydraulic conductivity and unconfined compressive strength of the soil were conducted in the laboratory. From the studies, it is found that lithomargic soil is near to the recommended specifications for soils to be used as liner material. Suitable materials for soil liners are then obtained by blending different types of locally available soils to achieve the required low hydraulic conductivity and good strength. To achieve specifications for the liner material lithomargic clay is blended with 15% and 20% marine clay by weight of lithomargic clay. From standard compaction control, the blended soil shows hydraulic conductivity lower than the 1x10-7 cm/s. Acceptable zones (AZ) are constructed on the compaction plane to meet design objectives for hydraulic conductivity. It's strength properties show that the soil possesses higher strength than the recommended minimum strength of 200kPa, to support the overburden pressure imposed by the waste body. From the laboratory test results, it can be concluded that lithomargic clay blended with marine clay satisfies the requirements for a good soil liner material. © 2012 CAFET-INNOVA TECHNICAL SOCIETY.Item Fatigue and Engineering Properties of Chemically Stabilized Soil for Pavements(Springer, 2013) Lekha, B.M.; Ravi Shankar, A.U.; Goutham, G.Soil stabilization is a technique to improve the weak soils and making them to meet certain requirements of the specific engineering projects. The type of soils available in Dakshina Kannada region of Karnataka State is laterite and Lithomarge clay. Its Plasticity Index is very high due to the presence of high percentage of silt and clay content. In the present investigation, an attempt is made to study the behaviour of laterite with and without adding chemicals. A chemical named Zycosoil, when added to water and mixed with soil alters its engineering properties that depend upon the type of the soil and dosage of chemical. These chemicals are liquid additives, which act on the soil to reduce the voids between soil particles and minimize adsorbed water in the soil for maximum compaction. In the present study, the effectiveness of Zycosoil in stabilizing the laterite soils of South Canara district is investigated through laboratory experiments. Various geotechnical properties are studied and correlations between different geotechnical properties and improvement in the soil properties with different percentages of chemical additions are derived. The important properties such as index properties, compaction characteristics, unconfined compressive strength parameters, California bearing ratio values and fatigue behaviour were studied. The results obtained indicate that there is an improvement in almost all properties with the addition of Zycosoil. © 2012 Indian Geotechnical Society.Item Influence of Granulated Blast Furnace Slag and Cement on the Strength Properties of Lithomargic Clay(Springer India sanjiv.goswami@springer.co.in, 2017) C. Sekhar, D.C.; Nayak, S.; Preetham, H.K.Utilizing industrial byproducts in soil stabilization benefits the economic, environmental and social benefits. Granulated blast furnace slag is a byproduct of iron and steel industry having oxides similar to that of cement but in different proportions. This study describes experimental results achieved by the use of granulated blast furnace slag (GBFS) and cement in stabilizing lithomargic clay for geotechnical applications. Soil was replaced by GBFS in percentages of 10, 15, 20, 25, 30, 35, 40, 45, 50% and cement of 2, 4, 6, and 8% by dry weight of soil is added. Various experimental studies like specific gravity, Atterberg limits, compaction, UCS, CBR and triaxial compression test, were performed on samples to understand the effect of these mixes on their few index and strength properties. The study also includes an investigation on a combination of optimum percentage of GBFS with varying percentage of cement and lime on their shear parameters. The study result shows significant improvement in the strength properties of the mixes. Hence it can be concluded that lithomargic clay stabilized with GBFS and cement/lime satisfy the strength requisite to be employed in the numerous geotechnical applications. © 2017, Indian Geotechnical Society.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 Numerical Investigation of Consolidation Induced by Prefabricated Horizontal Drains (PHD) in Clayey Deposits(Springer Science and Business Media Deutschland GmbH, 2021) Menon, A.R.; Bhasi, A.In this work, the process of prefabricated horizontal drains (PHD) induced consolidation in clayey embankment fills is investigated by a numerical approach. Based on spacing parameters, the suitability of axisymmetric and plane strain conditions for modeling the drain has been studied, and the suitability zones and matching functions have been proposed. The implications of the use of elastoplastic models to simulate the behavior of in situ soil on the suitability zones and matching functions have also been studied. The numerical results were compared with the analytical unit cell solutions for axisymmetric and plane strain conditions. Further, the effect of PHD in improving the consolidation behavior of various soil types has been analyzed in terms of pore pressure dissipation and settlement. The studies showed that the drain improved ground is best modeled under axisymmetric conditions at lower spacing ratios, and plane strain conditions simulate the more distantly spaced cases. PHD was found to accelerate the consolidation process in soft soils significantly, and the effect was found to be most prominent in highly plastic soils. © 2020, Springer Nature Switzerland AG.Item Experimental Studies and its Application using PLAXIS-2D for Lithomargic Clay Stabilized by GBFS and Lime(Springer Science and Business Media Deutschland GmbH, 2021) Mahesh Bhat, K.; Nayak, S.Lithomargic clay is found along the Eastern and Western coasts of Southern India. Presence of weak soils like lithomargic clay below the foundations, cause serious problems when they come in contact with water, and non-availability of stronger fill materials locally, to replace them is a challenge to foundation engineers. An attempt has been made in this paper to improve the strength of lithomargic clay by chemical stabilization using Lime and Granulated Blast Furnace Slag (GBFS). Disposal of massive amounts of industrial waste, GBFS, has become an environmental problem and utilization of the same for soil stabilization would be a sustainable solution for disposal. To optimize the use of lime and understand the mechanism behind the gain in strength, laboratory experiments were conducted on lithomargic clay, by replacing it with varying amounts of GBFS and addition of different percentages of lime. The optimum lime and GBFS content were found to be 4% and 20% respectively. Further optimization was done by mixing lithomargic clay with 4% lime and 20% GBFS and a significant strength improvement was observed. SEM and XRD analyses were conducted on the stabilized soil and the increase in strength was established from structural changes and formation of compounds like CSH and CASH. PLAXIS 2D was used to understand the settlement behavior of both the unstabilized and stabilized soils below strip foundations of varying widths. From load settlement analysis, it was observed that the net allowable pressure increases with increase in GBFS content and further increases with addition of lime to soil stabilised with optimum GBFS. © 2021, The Author(s), under exclusive licence to Springer Nature Switzerland AG.Item Hydroxyapatite–Clay Composite for Bone Tissue Engineering: Effective Utilization of Prawn Exoskeleton Biowaste(Multidisciplinary Digital Publishing Institute (MDPI), 2023) Satish, P.; Hadagalli, K.; Praveen, L.L.; Nowl, M.S.; Seikh, A.H.; Alnaser, I.A.; Abdo, H.S.; Mandal, S.Hydroxyapatite (HA, Ca10(PO4)6(OH)2)-based porous scaffolds have been widely investigated in the last three decades. HA, with excellent biocompatibility and osteoconductivity, has made this material widely used in bone tissue engineering. To improve the mechano-biological properties of HA, the addition of clay to develop HA-based composite scaffolds has gained considerable interest from researchers. In this study, a cost-effective method to prepare a HA–clay composite was demonstrated via the mechanical mixing method, wherein kaolin was used because of its biocompatibility. Prawn (Fenneropenaeus indicus) exoskeleton biowaste was utilized as a raw source to synthesize pure HA using wet chemical synthesis. HA–clay composites were prepared by reinforcing HA with 10, 20, and 30 wt.% of kaolin via the mechanical mixing method. A series of characterization tools such as XRD, FTIR, Raman, and FESEM analysis confirmed the phases and characteristic structural and vibrations bonds along with the morphology of sintered bare HA, HA–kaolin clay composite, and kaolin alone, respectively. The HA–clay composite pellets, uniaxially pressed and sintered at 1100 °C for 2 h, were subjected to a compression test, and an enhancement in mechanical and physical properties, with the highest compressive strength of 35 MPa and a retained open porosity of 33%, was achieved in the HA–kaolin (20 wt.%) clay composite, in comparison with bare HA. The addition of 20% kaolin to HA enhanced its compressive strength by 33.7% and increased its open porosity by 19% when compared with bare HA. The reinforcement of HA with different amounts (10, 20, 30 wt.%) of kaolin could open up a new direction of preparing biocomposite scaffolds with enhanced mechanical properties, improved wear, and better cell proliferation in the field of bone tissue engineering. © 2023 by the authors.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 LtdItem Integrated smart dust monitoring and prediction system for surface mine sites using IoT and machine learning techniques(Nature Research, 2024) Tripathi, A.K.; Mangalpady, M.; Parida, S.; Durgesh Nandan, D.; Elumalai, P.V.; Prakash, E.; Joshua Ramesh Lalvani, J.S.C.; Koppula, K.S.The mining industry confronts significant challenges in mitigating airborne particulate matter (PM) pollution, necessitating innovative approaches for effective monitoring and prediction. This research focuses on the design and development of an Internet of Things (IoT)-based real-time monitoring system tailored for PM pollutants in surface mines, specifically PM 1.0, PM 2.5, PM 4.0, and PM 10.0. The novelty of this work lies in the integration of IoT technology for real-time measurement and the application of machine learning (ML) techniques for accurate prediction based on recorded dust pollutants data. The study's findings indicate that PM 1.0 pollutants exhibited the highest concentration in the atmosphere of the ball clay surface mine sites, with the stockyard site registering the maximum levels of PM pollutants (28.45 µg/m3, 27.89 µg/m3, 26.17 µg/m3, and 27.24 µg/m3, respectively) due to the dry nature of clay materials. Additionally, the research establishes four ML models—Decision Tree (DT), Gradient Boosting Regression (GBR), Random Forest (RF), and Linear Regression (LR)—for predicting PM pollutant concentrations. Notably, Random Forest demonstrates superior performance with the lowest Mean Absolute Error (MAE) and Root Mean Squared Error (RMSE) at 1.079 and 1.497, respectively. This comprehensive solution, combining IoT-based monitoring and ML-based prediction, contributes to sustainable mining practices, safeguarding worker well-being, and preserving the environment. © The Author(s) 2024.