Browsing by Author "Preetham, H.K."

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A Study on the Behaviour of Stone Columns in a Layered Soil System
(Springer, 2020) Nayak, S.; Balaji, M.; Preetham, H.K.
Stone columns are one of the cost-effective and efficient methods for improving the ground which strengthen the soil and reduce the settlements. The study of the behaviour of stone columns in layered soils is of great importance. In this paper, results obtained from the experiments done on the stone columns with varying thickness of clayey silt soil (lithomargic clay) at bottom and the lateritic soil at the top are discussed. The lateritic layers are varied from top for a depth of 1D to 5D where D is the stone column diameter. Experiments were performed on untreated soils alone, soil with the ordinary stone column, geogrid encased stone column with and without additional horizontal reinforcement called basal layer to geogrid encased stone column in lithomargic clay. Similar experiments were conducted using lateritic soil. By considering layered combination of these two soils, experiments were also performed on ordinary stone column, geogrid encased stone column and geogrid encased stone column with basal layer. Laboratory tests were conducted in a unit cell on the floating stone column of diameter 60 mm. The load capacity of the stone column and bulging characteristics are significantly affected with the increase in the layers of lateritic soil. The encasement of stone column enhances the stone column’s capacity and reduces the bulging. The additional horizontal reinforcement layer also showed a significant impact on the load capacity of the stone column. Experiments conducted were modelled and analysed using PLAXIS 2D software package. © 2019, Springer Science+Business Media, LLC, part of Springer Nature.
Assessment of the Geotechnical Properties of Red Earth Stabilized Using Quarry Dust and Cement
(Springer Science and Business Media Deutschland GmbH, 2022) Nayak, S.; Preetham, H.K.; Prakash, S.D.
The present investigation aims at improving the engineering properties of red earth by incorporating quarry dust (QD) and analyze the results thus obtained by conducting a comparative study with the basic soil. Red earth is widely spread over a large part of peninsular India. Red earth/red soil could yield better results by the addition of rough-textured granular quarry dust and a hydraulic binder like cement. QD is the output from the rubble crushing units. Red earth was replaced with different proportions of quarry dust by dry mass of the soil: QD (5â€“30%, with an increment of 5%) with cement (2â€“6%) for the optimum QD-soil mix. The geotechnical properties like specific gravity, consistency limits, compaction, unconfined compressive strength (UCS), and triaxial compression test were performed on the red earth as well as on the mixes as per Indian Standard Codal provisions. UCS test results conclude that an optimum percentage of replacement of red earth by QD is 10% which yielded maximum strength than other mixes. It was observed that on replacement of red earth by granular quarry dust and cement, the shear strength properties and other geotechnical properties were improved. Thus, the utilization of granular industrial by-products has proven to be socially and economically beneficial. Â© 2022, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.
Effect of Drying Temperature and Rewetting on the Engineering Properties of Marine Clay
(Springer, 2020) Nayak, S.; Preetham, H.K.
This paper presents an experimental investigation on the influence of drying marine clay at different temperatures of 27 °C (room temperature air drying), 40 °C, 60 °C, 80 °C, 100 °C and 150 °C (oven drying) on its geotechnical properties. The same soil dried at various temperatures is then rewetted for 7 and 28 days and examined for its variation in the engineering properties. Investigation includes gradation analysis, consistency limits, compaction characteristics, shear strength properties and California bearing ratio. For the level of significance on the drying temperature variation, one-way analysis of variance (ANOVA) is performed using the Microsoft Excel software. Laboratory test results showed a decrease in clay size fractions and an increase in silt and sand size particles with increased drying temperature. Liquid limit and plasticity index decrease with an increase in drying temperature till 100 °C. Improved compaction characteristics, unconfined compressive strength, long-term stress-strain behaviour and California bearing ratio were found upon drying the soil at 100 °C. These results are useful in sample preparation prior to testing, also in specific geotechnical applications of underground storage of radioactive waste, an alternative to crushed rocks in pavement and ground source. Rewetting of the dried soil did not show much variation in gradation, index and compaction properties which are compared with the same properties of soil tested immediately. © 2020, Springer Science+Business Media, LLC, part of Springer Nature.
Experimental investigation on the stabilization of soft clay using granulated blast furnace slag
(2019) Preetham, H.K.; Nayak, S.; Surya, E.V.
Soft clay is associated with a soft consistency and poor shear strength. High percentage fines lead to higher liquid limit and lower plasticity index. Low bearing capacity and excessive settlement lead to uneconomic engineering structure constructed over it. There is a serious need to mitigate this problem and hence soil stabilization is the need of the hour. In the present study, Granulated Blast Furnace Slag (GBFS) which is an industrial waste/by-product of steel industry is used as a stabilizer to improve the geotechnical property of the soft clay. Soft clay is replaced by granulated blast furnace slag in various percentages by weight (10%, 20%, 30%, 40% and 50%) and examined for its plasticity, compaction and strength properties of the mix. From the experimental investigation, it is shown that the plasticity index decreases and unconfined compressive strength (UCS) increases upon addition of slag to the soil. With the curing age, UCS value increased indicating the chemical reaction between free lime and soil. 40% slag replacing the soft clay is recommended as stabilizer as it gave the maximum increase in UCS value compared to the rest mix. Based on the laboratory work, it can be concluded that granulated blast furnace slag can be used as a potential stabilizer for soft clay and also largely solves the problem of disposal of slag. � 2019 IOP Publishing Ltd. All rights reserved.
Experimental investigation on the stabilization of soft clay using granulated blast furnace slag
(Institute of Physics Publishing helen.craven@iop.org, 2019) Preetham, H.K.; Nayak, S.; Surya, E.V.
Soft clay is associated with a soft consistency and poor shear strength. High percentage fines lead to higher liquid limit and lower plasticity index. Low bearing capacity and excessive settlement lead to uneconomic engineering structure constructed over it. There is a serious need to mitigate this problem and hence soil stabilization is the need of the hour. In the present study, Granulated Blast Furnace Slag (GBFS) which is an industrial waste/by-product of steel industry is used as a stabilizer to improve the geotechnical property of the soft clay. Soft clay is replaced by granulated blast furnace slag in various percentages by weight (10%, 20%, 30%, 40% and 50%) and examined for its plasticity, compaction and strength properties of the mix. From the experimental investigation, it is shown that the plasticity index decreases and unconfined compressive strength (UCS) increases upon addition of slag to the soil. With the curing age, UCS value increased indicating the chemical reaction between free lime and soil. 40% slag replacing the soft clay is recommended as stabilizer as it gave the maximum increase in UCS value compared to the rest mix. Based on the laboratory work, it can be concluded that granulated blast furnace slag can be used as a potential stabilizer for soft clay and also largely solves the problem of disposal of slag. Â© 2019 IOP Publishing Ltd. All rights reserved.
Geotechnical Investigations on Marine Clay Stabilized Using Granulated Blast Furnace Slag and Cement
(Springer, 2019) Preetham, H.K.; Nayak, S.
Marine clay is present along the coastal region all around the world. This soil is highly problematic and unfit to support any engineering structures. They are characterized by high liquid limit, high plasticity index with low shear strength and high compressibility. The primary by-product generated from the ferrous industry is granulated blast furnace slag (GBFS), and CaO present in GBFS acts as a binding agent. This paper describes the detailed experimental results by incorporation of GBFS and cement to the marine clay. Soil was replaced by GBFS in various percentages (10%, 20%, 30%, 40% and 50%) and addition of cement (2%, 4%, 6%, 8% and 10%) in percentage of dry weight of soil. Soil and various mixtures are examined for its geotechnical properties, which include specific gravity, consistency limits, compaction characteristics, unconfined compression strength and strength parameters. From the unconfined compression test results, 40% GBFS replacing the marine clay is concluded as the optimum mix. Improvement in the strength is due to the formation of CSH, CAH, CASH and other cementitious compounds which are observed in SEM and XRD studies. From the investigation, it is concluded that GBFS with or without cement can be used as a potential stabilizer for soft marine clay. © 2019, Springer Nature Switzerland AG.
Improvement in the Properties of Red Soil Using Granulated Blast Furnace Slag
(Springer Science and Business Media Deutschland GmbH, 2022) Preetham, H.K.; Nayak, S.; Jagapur, P.
In the current study, an attempt is made to improve the geotechnical properties of red soil using industrial by-product: Granulated-Blast Furnace Slag (GBFS). Red soil is distributed over large part of the peninsular region in India. Red soil could be effectively stabilized to yield better strength characteristics. GBFS is the primary by-product of the iron and steel industry. Red soil was replaced with varying percentages of admixture (GBFS) by dry weight of soil (5, 10, 15, 20 and 30%). Basic geotechnical properties like specific gravity, Atterberg limits, compaction, unconfined compressive strength (UCS) and triaxial compression test, were performed on the red soil as well as on the mixes as per Indian Standard Codal provisions. From the UCS test results, the optimum percentage of replacement of 15% was found. It was observed that on replacement with admixtures, the liquid limit was found to decrease which reduces the compressibility. The presence of CaO in GBFS has improved the shear strength and shear strength parameters of soil. Thus utilization of granular industrial by-product (GBFS) has proven beneficial in geotechnical structures. Â© 2022, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.
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.