Department of Civil Engineering

Indian Institute of Technology Palakkad&nbsp;(IIT Palakkad or IIT PKD) is a public autonomous&nbsp;engineering&nbsp;and&nbsp;research&nbsp;institute located in&nbsp;Palakkad,&nbsp;Kerala. It was&nbsp;one of the five new&nbsp;IITs&nbsp;proposed in the&nbsp;2014 Union budget of India. The campus was inaugurated on 3 August 2015. The institute has 94 faculty, 978 students, and 63 non-teaching staffs.

IT Palakkad currently offers four-year Bachelor of Technology (B.Tech) and two years MS programmes in 8 different engineering disciplines including&nbsp;Computer Science, Electrical, Mechanical, Civil among others.

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IIT Palakkad

Rapid population growth, urban sprawl, and increased agricultural production in the Apalachicola-Chattahoochee-Flint (ACF) river basin are threatening the availability of freshwater resources and greatly affecting the supply of freshwater to Apalachicola Bay, which supports a struggling shellfish industry. As a result, Alabama, Georgia, and Florida have been fighting over the allocation of ACF river basin water for the past three decades. The water conflict heats up every time there is drought in the basin. In the Southeast U.S., droughts are mainly caused by the La Niña phase of the seasonal-to-interannual climate variability phenomenon known as the El Niño Southern Oscillation (ENSO). Understanding and quantifying the impact of ENSO-induced climate variability on precipitation, soil moisture, streamflows, and groundwater levels can provide valuable information for sustainable management of water resources in this region. This study was undertaken to quantify the impact of ENSO on groundwater levels in the lower ACF river basin, an area highly dependent on groundwater for agricultural water use. Twenty-one observation wells with 30 years of monthly groundwater level data were used to study the ENSO-groundwater level relationship. Wavelet analysis techniques were used to study the teleconnection between ENSO and groundwater levels, while Mann-Whitney tests were conducted to quantify the impact. The effect of prolonged La Niña events on groundwater levels and their corresponding recovery periods were also studied. Results indicate a strong relationship between groundwater level fluctuations and ENSO. This relationship was found to be stronger during the recharge season (December-April) as compared to the non-recharge or agricultural irrigation season (May-November). The results obtained can be used to develop procedures for forecasting groundwater levels, which can then be used to better manage the groundwater resources of this region. © 2014 American Society of Agricultural and Biological Engineers.

World University root node

Transactions of the ASABE

Effect of ENSO-induced climate variability on groundwater levels in the lower apalachicola-chattahoochee-flint river basin

Post-grouting of deep foundations following installation is a proven technique for enhancing axial resistance. The grouting is performed either below the tip of the foundation only (e.g., post-tip-grouted drilled shafts) or at both the side and the tip (e.g., jetted, side, and tipgrouted precast piles). The interaction of such foundations in group placement is currently unknown. This research focused on the group behavior of post-tip-grouted drilled shafts and jetted, side, and tip-grouted piles at a center-to-center spacing of three times the pile/shaft diameter. The study revealed that the post-tip-grouted drilled shafts acted independently within the group (i.e., negligible group interaction), whereas jetted, side, and tip-grouted piles behaved as a block under axial loading. It was determined that side grouting of a foundation prior to tip grouting significantly increases the grout pressure developed during tip grouting and helps in the formation of a tip grout bulb via a spherical cavity expansion process. Thus, the side and tip grouting of adjacent foundations within a group increases the confining stress and relative density of the soil mass within the group, resulting in block behavior under top-down loading. In contrast, tip-only grouted foundations showed little if any increase in radial stress and radial soil displacement, resulting in minimal improvement of the soil stiffness between shafts; as a result there was no block behavior and a negligible group effect at the tip. Copyright © 2014 by ASTM Int'l (all rights reserved); Mon Jul 14 01:15:34 EDT.

Geotechnical Testing Journal

Experimental group behavior of grouted deep foundations

Florida. Dept

Field Testing of Jet-Grouted Piles and Drilled Shafts

University of Florida

Study of grouted deep foundations in cohesionless soils

AGU Fall Meeting Abstracts 2013, H53E

Calibration of Distributed Hydrologic Models Considering the Heterogeneity of the Parameters across the Basin

Indian Geotechnical Journal

Dynamic response of block foundations resting on soil–rock and rock–rock system under vertical excitation

Links of a transportation network are subject to several forms of frequent non-severe disruptions 1 like traffic incidents, snowing, flooding, road-space reallocations, road-space infiltrations, 2 infrastructural failures, etc. Disregarding the cause, they may be viewed as multiple simultaneous 3 disruptions on links' capacities. Though the disruption or failure of a single link is widely 4 studied, the area of multiple simultaneous disruptions on transportation networks is under-5 researched. Also, most of the existing studies assume probability distributions of capacity 6 disruptions to be known. The objective of this paper is to study multiple simultaneous 7 disruptions and to establish a consequent critical state. We assign different levels on links' 8 capacities and search for probability distributions over those levels that would result in a critical 9 state. The critical state is modeled as the one which effects in poor network performance and 10 comparably equal expected path costs, that makes it hard for a user to identify the better path (i.e. 11 it induces maximum indifference on expected utilities of alternative paths). We formulate the 12 critical state link disruption problem as a minimax optimization problem and solve it using a 13 coevolutionary algorithm. We evaluate network performance in terms of expected system travel 14 time. The formulation is exemplified by finding expected system travel time at the critical state 15 on test networks. It is also shown how the performance at critical state can be used to measure 16 network robustness.

a Critical State of Multiple Simultaneous Link Disruptions

Clays treated with lower cement contents often exhibit behaviour similar to stiff clays with planar failure surface under triaxial compression. In the present work the behaviour of a marine clay treated with 5 % cement, subjected to undrained triaxial compression tests is studied. The pre-consolidation pressure of the cemented clay due to the cementation bonding is observed to be very high. It is attempted to model the behaviour of cement treated clay using a bounding surface plasticity formulation as the plastic behaviour of the cemented clays within the yield surface has to be considered. The effect of cementation is included in the model as the pre-consolidation pressure obtained from consolidation tests. The tensile strength due to cementation bonds is included in the equation of the bounding surface. Simulations of the undrained triaxial compression tests on cemented clays are carried out and the results are validated with the experimental results. © 2012 Springer Science+Business Media Dordrecht.

Geotechnical and Geological Engineering

Undrained Triaxial Behavior of Cement Treated Marine Clay

The use of natural fibers such as coir for soil improvement is highly attractive in countries where such materials are locally and economically obtainable, in view of the preservation of natural environment and cost effectiveness. This paper discusses shear strength of clay reinforced with randomly distributed coir fibers based on a series of consolidated undrained triaxial compression tests. Test results show that major principal stress at failure for clay-coir fiber matrix increases with increase in fiber content (Wf) and fiber aspect ratio (Ar). For all the combinations of fiber contents and aspect ratios, failure principal stress envelope exhibits a curvilinear variation with a transition at a confining stress, known as critical confining stress. Separate regression analyses have been performed for observations below and above critical confining stress to develop mathematical models, which consider fiber content, aspect ratio, confining stress and plain soil characteristics as the input parameter, to predict major principal stress at failure for the clay-fiber composite. In general, the study identifies that the inclusion of discrete coir fibers in random fashion significantly improves the shear strength of clay and hence could be effectively used for the cases where in-place mixing of soil with fibers is possible (e. g., pavement sub-grade, landfill liner, small embankment). The developed regression models may be used in the design phase for the rough estimation of shear strength of the composite. © 2012 Springer Science+Business Media Dordrecht.

Influence of Randomly Distributed Coir Fibers on Shear Strength of Clay

Determination of critical state parameters are essential, when critical state soil mechanics based soil models are used for the analysis. Isotropic consolidation test and triaxial tests with accurate measurements of volume change and pore pressure are essential for the direct measurement of critical state parameters. However, in the conventional geotechnical engineering practice, isotropic compression tests are usually not conducted but only one-dimensional consolidation test are performed. The usual parameters reported in most of the soil investigation reports are the shear strength parameters c′ and φ{symbol}′ and the consolidation parameters such as compression index (Cc) and the recompression index (Cr) apart from, the overburden pressure σ0′ and the corresponding void ratio e0. The critical state parameters are seldom reported in most of the soil investigation reports. This paper explains a procedure to estimate the critical state parameters, in the absence of isotropic compression test data, based on one-dimensional consolidation tests and triaxial compression tests, using the equations of Modified Cam clay state boundary surface. Comparison of the calculated values from the suggested method with the measured values, on three reconstituted soils and one undisturbed soil, lends support to the validity of the proposed procedure. © 2013 Indian Geotechnical Society.