Faculty Publications
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Item Effect of soil parameters on dynamic cone penetration indices of laterite sub-grade soils from India(2009) George, V.; Nageshwar Rao, Ch.; Shivashankar, R.The focus of this study was on correlating the effect of grain-size, maximum dry-density (MDD), field moisture content, and the void ratios on penetration measured using the dynamic cone penetrometer (DCP) for laterite soils blended with fines. Tests were performed on soil samples compacted to MDD for moulding water contents set to the optimum moisture content (OMC), dry of OMC, and wet of OMC un-soaked condition. The results indicated that an increase in the fines-content caused a decrease in the MDD, and an increase in the OMC and the DCP penetration. Regressions were developed correlating various parameters. © Springer Science+Business Media B.V. 2008.Item A model study on accelerated consolidation of coir reinforced laterite and blended shedi soil with vertical sand drains for pavement foundations(2012) George, V.; Santosh, G.; Hegde, R.N.; Durga Prashanth, L.; Gotamey, D.; Ravi Sankar, A.U.Sub-grade soils of lateritic origin are frequently encountered in the construction of highway embankments in various regions of India, often comprise intrusions of soft lithomargic soils that result in large settlements during constructions, and differential settlements at later stages. This necessitates the use of appropriate soil improvement techniques to improve the load-carrying capacity of pavements. Coir is a natural fiber that can be used in place of geosynthetics and geogrids, and it is biodegradable and environment friendly. This work deals with the accelerated consolidation of un-reinforced and coir-reinforced laterite and blended lithomargic soils, provided with three vertical sand drains. The load-settlement characteristics were studied for various preloads ranging from 50kg (0.0013 N/mm2) to 500kg (0.013N/mm2) using circular ferro-cement moulds. It was observed that at lower preloads up to 300kg, the relative increase in consolidation (Cr) for randomly reinforced soil with vertical drains was significantly higher than that of un-reinforced soil without vertical drains. Also, the Cr for un-reinforced soil with vertical drains was quite higher than that of un-reinforced soil without vertical drains, with values above 38.71%. However, in the case of higher preloads of 450kg and 500kg, the Cr for randomly reinforced soil with vertical drains was insignificant, and the Cr for un-reinforced soil with vertical drains remained slightly higher at around 9.59% for similar comparisons. The aspect-ratio of coir fibers used was 1: 275. © 2012 Cafet-Innova Technical Society. All rights reserved.Item Accelerated consolidation of coir reinforced lithomargic laterite soil blends with vertical sand drains for pavements(2012) George, V.; Hegde, R.N.; Vardhana, M.V.; Santosh, G.; Gotamey, D.It is found that sub-grade soils of lateritic origin encountered in the construction of highway embankments in various regions of India, often comprise intrusions of soft lithomargic soils that result in large settlements during constructions, and differential settlements at later stages. This necessitates the use of appropriate soil improvement techniques to improve the load-carrying capacity of pavements. This work deals with the accelerated consolidation of un-reinforced and coir-reinforced laterite and blended lithomargic soils, provided with three vertical sand drains. The load-settlement characteristics were studied for various preloads ranging from 50kg (0.0013 N/mm2) to 500kg (0.013N/mm2). Studies were performed using circular ferro-cement moulds. It was observed that at lower preloads of up to 250kg, the relative increase in consolidation (Rct) for randomly reinforced soil with vertical drains was significantly higher than that of un-reinforced soil without vertical drains. Also, the Rct for un-reinforced soil with vertical drains was quite higher than that of un-reinforced soil without vertical drains, with an average value of 20.84%. In the case of higher preloads the Rct values for randomly reinforced soil with vertical drains were moderate with an average value of 22.67%. An additional increase of up to 27% at lower pre-loads and 11.83% at higher pre-loads was observed due to the effect of random reinforcement when compared to use of vertical drains alone. © 2012 ejge.Item TRANSYT-12 in the design and analysis of coordinated traffic signaling for three major junctions of Mangalore City(2012) George, V.; Hemanth, K.R.The present work deals with the application of TRANSYT-12, for the design of a co-ordination of the signals on three main junctions of the signal system for Mangalore city. The road network loop connecting PVS Junction, Hampanakatta, and Jyothi Junction, joining back to PVS Junction was analysed. The other nodes representing Bunts Hostel Junction, Navbharath Circle, and Karnataka Bank Junction are considered for their contribution to the traffic network loop, in addition to the flows arriving from a number of give-ways. The existing scenario, with the present system of fixed time isolated signals was compared to the alternate scenario with the use of coordinated signals, and improvements in the existing network. It was found that the performance of traffic flow in the network could be improved considerably by adopting various remedial measures. Studies were also performed for the year 2012. © 2012 CAFET-INNOVA TECHNICAL SOCIETY.Item Iterative zone-reclassification in trip generation, and cube-based distribution for Bangalore(2012) George, V.; Subramanyam, U.V.; Mahendrakar, A.S.This study deals with the development of an approach to model trip-generation and distribution for the City of Bangalore using data compiled in 2002. Since the initial attempts at development of reliable trip-generation regressions using SPSS were un-successful, an iterative zone-reclassification approach was adopted in modelling the trip-productions and attractions. The reclassification of zones was performed based on the assumed influence of various groups of zones, the location of production and attraction centres and their nearness, and the improvement in the R-square value of regressions developed at each iteration. Finally, the 159 zones of the city were broadly categorized into twelve influence areas, and the trip-generation and distribution studies were performed using CUBE software. The predictions for the base year were verified with the actual data. Predictions for 2011 and 2021 were then performed. © 2012 CAFET-INNOVA TECHNICAL SOCIETY.Item Effect of Soil Parameters on Resilient Modulus Using Cyclic Tri-Axial Tests on Lateritic Subgrade Soils from Dakshina Kannada, India(Springer International Publishing, 2018) Kumar, A.; George, V.Resilient modulus (Mr) of a soil is used as a basic input in the analysis of sub-grade and sub-base in the mechanistic empirical design approaches. The present work focuses on evolving a cost effective approach for the determination of resilient modulus in the laboratory based on tests performed using the CBR method, and the DCP. Lateritic sub-grades in India exhibit wide-ranging variations in strength and stiffness due to varying fines content, and other characteristics. Additionally, soils of lateritic origin with a higher proportion of fines, also called as lithomargic soils, pose difficulties to pavement engineers due to the poor supporting strength. In order to investigate the strength and stiffness of a wide variety of lateritic soils, it was proposed to perform tests on lateritic soils blended with lithomargic fines in this study. The study focuses on correlating the effect of grain-size, maximum dry-density (MDD), and optimum moisture content (OMC) on the resilient modulus (Mr) measured using the cyclic tri-axial test for various blends of lateritic soils. Tests were performed on soil samples compacted to MDD for molding water contents set to the OMC, dry-side of OMC, and the wet-side of OMC. The results indicated that an increase in the fines-content resulted in an increase in the OMC, and a decrease in the MDD and Mr values. Regressions were developed correlating the fines content to the resilient modulus. This study is expected to provide the necessary basis for estimating the strength of a wide variety of lateritic sub-grades based on the fines content. © 2018, Springer International Publishing AG, part of Springer Nature.