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

Climate hazard group infrared precipitation with station data (CHIRPS) is one of the latest high-resolution quasi-global satellite-based rainfall datasets. It is available in daily, pentadal and monthly time scale from the year 1981 to present. In the present study, the performance of the CHIRPS product is evaluated over the Kerala state on a monthly time scale. For the evaluation of this climate hazard group, product rain gauge data from sixty-seven-gauge stations which are distributed all over Kerala was used. Validation statistics such as mean absolute error (MAE), multiplicative bias (Mbias), Nash–Sutcliffe efficiency (NSE) and coefficient of determination (R2) were used for the evaluation. The results show that the efficiency of this satellite rainfall estimate is very high with an overall NSE value of 0.72. The accuracy of CHIRPS data was very high mainly in the low-lying areas of Kerala, i.e. at the coastal areas and it was found to be decreasing when in approaches towards the Western Ghats. Overall CHIRPS product is good enough for use in water resource applications in Kerala. © Springer Nature Singapore Pte Ltd 2021.

World University root node

Evaluation of chirps satellite rainfall datasets over kerala, india

Reinforced soil walls are cost-effective alternatives to earth-retaining structures which can accommodate more settlements than conventional retaining wall systems. Ideally, freely draining granular materials such as sand are used as the backfills. But, scarcity of ideal granular materials necessitated the researchers to explore other alternatives. A large quantity of construction and demolition waste (CDW) is being generated in India as well as in other parts of the world. In this study, the feasibility of using CDW as a backfill for geosynthetic-reinforced soil walls has been attempted. The geotechnical properties of CDW were determined in order to ascertain whether their properties comply with existing specifications. It was observed that the geotechnical properties of CDW meet the requirements of an ideal backfill material for MSE walls mandated by various standards. Further, the numerical studies were conducted to study the deformation behavior of reinforced soil wall with CDW backfill immediately after construction. The assumptions made in the conventional design regarding the failure mechanism were also investigated. The paper highlights the potential use of processed CDW as a sustainable backfill material for reinforced walls. © 2020, Indian Geotechnical Society.

Indian Geotechnical Journal

Geosynthetic-Reinforced Soil Walls with Sustainable Backfills

In the present study, performance of geosynthetic reinforced MSE walls backfilled with locally available marginal lateritic soil at the onset of rainfall infiltration was investigated. Two different types of geosynthetics reinforcements were used. One was a conventional type of geogrids usually used in MSE walls, and the other was composite geogrids. Seepage analysis, stability analysis and strength and deformation analysis were carried out on MSE walls with rainfall simulated for a duration of 3 days. In case of geogrid reinforced soil wall (GR-W), the suction within the backfill was lost completely at the end of 2.176 days of rainfall, whereas suction was maintained even at the end of 3 days of rainfall in walls reinforced with composite geogrids (CGR-W). From the stability analysis, it was observed that the factor of safety of GR-W decreased at the onset of rainfall infiltration with time and reached less than the desirable value of less than 1.5 in 2.125 days of rainfall. The factor of safety of CGR-W was maintained at 1.88 throughout the period of rainfall. The facing deformation in GR-W was found to increase, with a maximum of 3.2 times increase at the end of three days of rainfall. Similarly, there was an increase in maximum tensile load mobilized in the reinforcements in GR-W, whereas in the case of CGR-W, the influence of rainfall was negligible. From the present study, it can be concluded that the presence of composite geogrids improves the overall performance of MSE walls backfilled with marginal lateritic backfills. © 2021, The Author(s), under exclusive licence to Springer Nature Switzerland AG part of Springer Nature.

International Journal of Geosynthetics and Ground Engineering

Performance of Geosynthetic Reinforced MSE Walls with Marginal Backfills at the Onset of Rainfall Infiltration

The current study analyses the effect of root zone soil moisture in the calibration and validation of Soil and Water Assessment Tool (SWAT) model. A multi-algorithm, genetically adaptive multi-objective method (AMALGAM) is used for the calibration of the model. The multi-variable calibration considering both streamflow and soil moisture is compared with a single-variable calibration considering streamflow and then analysed the effectiveness of root zone soil moisture in the calibration of SWAT. The results of the analysis show that the root zone soil moisture significantly influences the simulation of evapotranspiration component in SWAT. The SOL_AWC and SOL_K are found to be the key parameters for the simulation of hydrological fluxes in SWAT. The multi-variable calibration at the watershed outlet ensures a better process representation and spatial prediction in SWAT compared to the single-variable calibration approach. © 2021, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.

Environmental Earth Sciences

Effect of root zone soil moisture on the SWAT model simulation of surface and subsurface hydrological fluxes

An improved response function (IRF) based stochastic element free Galerkin method (SEFGM) is proposed for the stochastic bending analysis of laterally loaded thin plates. Young's modulus is considered as uncertain and its spatial variation is modelled as a homogeneous normal random field. Shape function method is used for random field discretization. In IRF method, the total displacement response is represented as the sum of a deterministic part and a stochastic part. The stochastic part is called as IRF and it is a function of the discretized set of random variables. Stochastic stiffness matrix is approximated using Taylor series expansion. A simplified expression for IRF in terms of stiffness derivatives and random variables is derived from the equilibrium considerations of system of stochastic equations. Direct simulations on the IRF combined with deterministic part of response can give the probabilistic characteristics of response quantities. The response characteristics of the plates obtained using the proposed method are compared with those obtained using Monte Carlo simulation (MCS). An ad-hoc response function (ARF) and second order perturbation (SOP) based SEFGM are also used for comparing the results. Square thin plates with two different boundary conditions are solved as the numerical examples. Kirchhoff-Love assumptions and plane stress conditions are considered. The deterministic EFGM used for bending analysis of plates calculates the out of plane deformations and rotations at various points. The probabilistic characteristics of these quantities are measured using the proposed IRF based SEFGM. A parametric study is conducted to investigate the capability of the proposed method in response moment calculations at various coefficients of variation (CV) and correlation length parameters of input random field. The response moments determined using the proposed method are found to be in good agreement with those obtained using MCS even at a CV of 30%. It is found that the proposed method can calculate the response moments accurately, regardless of the correlation length parameters of the input random field. These are attributed to the fact that the proposed IRF method considers the complete displacement response without any approximation. The probability density function and the cumulative distribution function of response quantities of plates calculated using the proposed method are observed to be comparable with those obtained using MCS. From a study on normalized computational times, the proposed IRF method is found to be computationally more efficient compared to MCS. In the proposed method, the stiffness derivatives and deterministic part of the displacement response are calculated outside the simulation loop. This along with the use of discretized set of random variables inside the simulation loop, calculates the IRF and hence the response statistics, that makes the method computationally more efficient compared to MCS. Copyright © 2021 by ASME

ASME International Mechanical Engineering Congress and Exposition, Proceedings (IMECE)

AN IMPROVED RESPONSE FUNCTION BASED STOCHASTIC MESHLESS METHOD FOR BENDING ANALYSIS OF THIN PLATES

Expansive soil which is found in several parts of India possesses high swelling and shrinkage properties. The volume change and uplift pressure generated in these soil deposits cause severe damage to the lightweight structures and pavements. In order to mitigate the problems associated with expansive soils, it is necessary to stabilize this soil. Among all the stabilization techniques, lime treatment is one of the best suitable methods for expansive soils. In the present study, lime stabilization technique is used to improve the engineering properties of black cotton soil including the resilient modulus value, which is important for mechanistic flexible pavement design. Optimum amount of lime required for stabilization was determined using Atterberg’s limits. Considerable increment was observed in unconfined compressive strength values and California bearing ratio values of black cotton soil stabilized with 6% lime. Repeated load triaxial tests under different confining pressures and deviatoric stress levels were conducted on the treated samples in order to determine the resilient modulus. The effect of curing period and moisture content on the resilient modulus was investigated. In order to study the durability of lime stabilized clayey subgrade soil, the effect of wetting and drying cycles on the engineering properties of the treated material was examined. The results show that the strength and stiffness characteristics of lime treated clay have considerably reduced after five wetting and drying cycles. © 2021, Springer Nature Singapore Pte Ltd.

Lecture Notes in Civil Engineering

Strength and Durability Characteristic of Lime Stabilized Black Cotton Soil

Being a challenge to deal with structural foundations in soft clays, several techniques were promulgated across the world. This paper presents the load–settlement behaviour of soft clay provided with soil-cement columns in test tanks. Based on the experimental work performed on 10% cement mixed single clay column resting on hard stratum simulating end bearing condition, it is revealed that load-carrying capacity of clay bed increased by 3–4 times that of virgin clay. Also, the load-carrying capacity of clay bed increased 5–7 times that of virgin clay with the group of three columns arranged in triangular pattern with centre to centre spacing of two times the diameter of column. Group capacity of soil-cement column is 1.5–2 times of single column which is not multiplicative of single column. UCC tests were carried to find out the optimum fibre content by varying the fibre content from 0 to 3%. From UCC test, it is observed that 2% fibre content is suitable for the present study considering the strength improvement and ease of mixing. It is observed from the tests that with the addition of 2% fibre in soil-cement column, load-carrying capacity of clay bed increased by 5.5–7.5 times when tested with group of columns. There is 10–20% increase in ultimate load-carrying capacity of soil-cement column after addition of fibre and the mode of failure of columns changed from brittle to bulging failure. © 2021, Springer Nature Singapore Pte Ltd.

Improvement of Soft Clay Bed Using Fibre-Reinforced Soil-Cement Columns

Use of industrial by-products to improve subgrade soils in flexible pavements is gaining popularity as a sustainable construction practice. Calcium carbide residue (CCR) is a by-product of acetylene gas industry. In this paper, an attempt has been made to evaluate the influence of calcium carbide residue in improving the performance of clayey subgrade soils. The improvement in resilient modulus of two clayey soils (with low plasticity and high plasticity) with the addition of calcium carbide residue is studied by carrying out repeated load triaxial tests. The influence of variation in moisture content on the repeated loading behaviour of virgin soils and CCR stabilized soils is examined. Two regression models (Universal and NCHRP model) reported in literature are found to exhibit very good fit with the experimental data. © 2018 Informa UK Limited, trading as Taylor & Francis Group.

International Journal of Geotechnical Engineering

Resilient modulus of clayey subgrade soils treated with calcium carbide residue

Sugarcane bagasse ash is available in abundance and it has significant pozzolanic reactivity. However, bagasse ash is currently disposed of as a waste in the major sugar-producing countries and its use in industrial-scale blended cement production is highly limited. A systematic review of the potential of bagasse ash for use as a pozzolan in concrete and the translation of the all-inclusive research outcomes from earlier research studies to the industry can enable its wider acceptance. Hence, this study undertakes a comprehensive review on the use of sugarcane bagasse ash in concrete. The physical, chemical and pozzolanic characteristics of sugarcane bagasse ash and their effects on the properties of concrete are reported. The use of bagasse ash is found to result in a notable increment in the compressive and tensile strengths up to 20% replacement. Nevertheless, delay in setting times and reduction in workability are widely reported. The resistance of bagasse ash blended concrete against chloride ion penetration, water permeability and air permeability were also reviewed and a considerable drop in the permeability was reported over the conventional cement concrete. Opportunities for the effective recycling of bagasse ash and their benefits in India, the second-largest sugar producer in the world, are presented. © 2021, Society for Sugar Research & Promotion.

Sugar Tech

Sustainable Opportunities for Sugar Industries Through Potential Reuse of Sugarcane Bagasse Ash in Blended Cement Production

Changes to water resources are critical to all sectors of the economy. Climate change will affect the timing and quantity of water available in the environment as well as have an adverse effect on the quality of that water. Floods, droughts, and changing patterns of water scarcity—when water is not available in sufficient enough quantities or of a suitable quality at the right time to fulfill demand—are all critical factors when considering how and where Indiana will be able to economically develop in the future. Management of water resources will become even more important as different sectors try to minimize the risk of water scarcity in the face of increasing climate variability. This paper focuses on observed changes to Indiana’s water resources and how the availability and quality of those resources are likely to change in the face of future climate. Generally, Indiana is becoming wetter but with the projected increase coming primarily in the winter and spring. Summer water use will increase the likelihood of water shortages and the need for improved water management. In particular, Indiana may benefit from investment in methods to increase short-term storage of water—retaining more of the overabundance from winter and spring to relieve summer shortages. © 2021, The Author(s), under exclusive licence to Springer Nature B.V. part of Springer Nature.