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

To perform crash analysis on large road networks, the network has to be segmented into smaller units. Existing approaches split road networks into road segments such that they result in (a)segments with constant length, (b) segments where attributes are homogeneous, (c) segments where crash-locations are interdependent. This study proposes a novel hybrid segmentation approach, especially to cater for network-level analysis. Road entities at network scale include intersections and mid-blocks which are dissimilar in their functionality as well as geometry. The effective zones of intersections and mid-blocks needs to be delineated, as there exists spatial correlation between crashes in them. The first level of the hierarchical hybrid segmentation uses crash locations to define intersections’ neighborhood. Subsequently, mid-blocks are segmented using attribute consistency. To illustrate its applicability on road networks in Low-and-Middle Income Countries (LMIC), we exemplify the methodology employing remote extraction of spatial attributes. The potential of Geographic Information System (GIS), Remote Sensing (RS), and Artificial Intelligence (AI) have been used for remote extraction of spatial features, including curvature, sight distance, land use, and network attributes. We compare the performance of hybrid segmentation with three other typical segmentation approaches. Crash susceptibility models using binary logistic regression, relating crashes and segment-specific attributes obtained with each of the four segmentation approaches were developed. The model developed with the proposed hybrid segmentation outperforms models with other segmentation approaches, in terms of goodness-of-fit and prediction accuracy. The proposed methodology can be readily used by practitioners for crash analysis. © 2021 Elsevier Ltd

World University root node

Safety Science

Hybrid segmentation approach to identify crash susceptible locations in large road networks

Sugar industries generate large quantities of sugarcane bagasse ash as a by-product, which is subsequently landfilled despite its potential to be used as a supplementary cementitious material in concrete, similar to the currently used rice husk ash. Even though the pozzolanic nature of bagasse ash is known, the performance of bagasse ash along with other industrial by-products such as tire rubber powder in construction products has not yet been investigated. Hence, the combined use of uncontrolled burnt sugarcane bagasse ash as a supplementary cementitious material and rubber tire powder as fine aggregate for the development of cement concrete and alkali-activated concrete with minimum characteristic compressive strength 35 MPa is investigated in the present study. It was observed that a maximum of 10% unprocessed bagasse ash along with 10% rubber powder could be used in concrete paver blocks. Besides, 30% unprocessed bagasse ash by weight of the binder can be used along with 10% rubber powder in the case of alkali-activated concrete. Together, up to 40% of the ingredients in alkali-activated concrete were effectively replaced with bagasse ash and rubber powder. The influence of different parameters on the performance of alkali-activated binders was also investigated and the optimum performance was witnessed for specimens activated with 8 M sodium-based activators and cured at ambient conditions. Therefore, bagasse ash and waste rubber tire powder can be used as value-added products in construction instead of their disposal as waste. © 2022, The Author(s), under exclusive licence to Society for Sugar Research & Promotion.

Sugar Tech

Reuse of Uncontrolled Burnt Bagasse Ash from Sugar Industries with Waste Rubber Powder in Construction: A Waste to Wealth Approach for Sugar Mills

Seasonal variations in the soil moisture content can result in significant changes in soil suction. Rainfall infiltration can cause loss of matric suction in the unsaturated lateritic soil. Several failures are reported in lateritic soil slopes in Kerala, associated with rainfall. Geosynthetics are generally used for improving the stability of soil structures constructed with poorly draining soils. Shear strength at the interface of unsaturated lateritic soil with geosynthetics plays a crucial role on the internal stability of geosynthetics reinforced structures. The present study investigates the influence of rainfall-induced wetting on shear strength of lateritic soil and lateritic soil-geosynthetics interface. Lateritic soil was collected from a site in Kerala, which was subjected to rainfall-induced slope failure. Geotechnical characterization of the soil was carried out. Shear testing was conducted on soil samples of size 305 × 305 × 200 mm. When the moisture content was increased by 4% due to wetting, the shear strength of the lateritic soil was reduced by 20%. In contrast, the corresponding reduction in strength at the interface for the soil–geosynthetic system was only 3%. Similarly, an increase in moisture content by 8% due to wetting resulted in a reduction in strength by 30% and 4% for soil–soil and soil–geosynthetic systems, respectively. © 2022, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.

Lecture Notes in Civil Engineering

Influence of Rainfall on the Interface Shear Strength of Unsaturated Lateritic Soil with Geosynthetics

This study aims to enhance daily precipitation forecasts over the Indian subcontinent through post-processing the Global Ensemble Forecast System (GEFS) outputs using Analog (AN) and Logistic Regression (LR) techniques. Both raw and post-processed GEFS precipitation forecasts were evaluated against the Indian Meteorological Department observed dataset using probabilistic and deterministic forecast evaluation metrics, namely Brier Skill Score (BSS) and Root Mean Square Error (RMSE), respectively. Results found that the LR and AN post-processing method considerably improved short to medium range (1–7&nbsp;day) precipitation forecasts over India. A comparison of the techniques with GEFS version 12 (GEFSv12) forecasts across different basins suggests that both methods were able to provide skillful precipitation forecasts in all the river basins, except that the AN method underperformed for the western ghats. The seasonal analysis also showed that the raw and the post-processed forecasts under-performed during the monsoon season while performing comparatively well during the non-monsoon season. The comparison of LR and AN methods showed that LR outperformed the AN method. The forecasts enhanced using both the post-processing techniques were more reliable and skillful than the GEFSv12 precipitation forecast. Comparison of the recent GEFS version with the older version of GEFS showed that the performance of the earlier version was slightly better compared to the latest version, however none of the forecasts can be used for decision making purposes without post-processing.

Journal of Hydrology

Improving short to medium range GEFS precipitation forecast in India

International Conference on Resource Sustainability - Sustainable Pavement Technologies (2021)

Flexural fatigue behavior of uncracked steel fibre reinforced concrete: A comparative study

The present study investigated the influence of biochar on various geotechnical properties of clayey soil. Biochar, a carbon-rich product, was amended with the soil at different percentages such as 5, 10 and 15%. Laboratory tests were conducted to evaluate the feasibility of utilization of biochar in enhancing the integrity of soil slopes with an emphasis on landfill covers and bioengineered slopes. Scanning electron microscopy (SEM) tests were conducted to analyse micro-porous structure of biochar and soil-biochar mix. The SEM micrographs indicated the porous structure of the biochar and a good interaction with the clay particles. It was concluded from the present study that the biochar amended soil can have steeper and stable slopes compared to soil without biochar amendments. The compressibility of the soil was also decreased with biochar amendment. © 2021, Springer Nature Singapore Pte Ltd.

Problematic Soils and Geoenvironmental Concerns

Influence of Biochar on Geotechnical Properties of Clayey Soil: From the Perspective of Landfill Caps and Bioengineered Slopes

Back-to-Back Mechanically Stabilized Earth (MSE) walls have become an integral part of the transportation infrastructures, especially as ramps, bridge approaches, etc. The permeability, strength and constructability attributes of well-graded granular soils have rendered them as the most suitable fill material for MSE walls. However, the scarcity of such good materials compels the usage of locally available soil with high fine content (marginal fill) having low permeability and high plasticity characteristics, which can cause excessive wall deformation or even failure, if not adequately designed and constructed. This study focused on the assessment of overall performance of back-to-back MSE walls with a trapezoidal marginal fill zone surrounded by a near-optimal amount of select fill (i.e., hybrid-fill) as an alternative to the wall with select fill only. The behaviour of hybrid-fill wall at the end of construction and during heavy rainfall infiltration were investigated through finite element modelling and compared with fully select fill and fully marginal fill walls. The study revealed that the overall performance (i.e., horizontal and vertical deformations, reinforcement tension, and factor of safety) of the hybrid-fill wall with 31–47% select fill is much better than that of fully marginal fill wall, especially during the extreme rainfall infiltration scenario. The response of this hybrid configuration is even comparable with that of fully select fill wall, suggesting the proposed hybrid-fill wall as a stable as well as cost-efficient alternative system in locations where sufficient quantity of well-graded soil is not readily available. © 2020 Elsevier Ltd

Transportation Geotechnics

Numerical evaluation of the performance of back-to-back MSE walls with hybrid select-marginal fill zones

Vast deposits of high water content soft clays pose severe problems and are not suitable for construction of engineering projects due to their inadequate bearing capacity and inherent large swelling and shrinkage ability. Deep soil mixing (DSM) is one of the widely accepted methods for improving soft soil properties like increase in bearing capacity and reduction in settlement that are of utmost importance for the construction of any structure. In this study, ground granulated blast furnace slag (GGBS)-based geopolymer was used to investigate its efficiency as a sustainable replacement to cement for DSM applications, thereby reducing the carbon footprint. A total of 27 GGBS-geopolymer mixes and 9 cement-treated reference mixes were cast and tested for strength and durability characteristics. The variables of the study include binder content (10, 20, and 30%), activator/binder ratio (0.5, 0.75, and 1.0), and initial soil moisture content (0.75wL, wL, 1.25wL). Different tests were conducted to explore the properties of stabilised clays, such as unconfined compressive strength, flexural strength, and durability against wetting drying cycles. To meet the requirements of DSM application, binder dosage greater than 10% and A/B ratio greater than 0.5 were recommended. With an increase in initial soil moisture content, the strength of the treated specimens under unconfined compression and flexure reduced and thus increased binder dosage helps to meet the DSM requirements for high water content soils. From the present study, it can be concluded that using slag-geopolymer binder for stabilising soft soil is an effective and sustainable alternative to cement in DSM applications. © 2020, Springer Nature Switzerland AG.

Innovative Infrastructure Solutions

Experimental evaluation of strength and durability characteristics of geopolymer stabilised soft soil for deep mixing applications

Studies on the characterization and performance of residual sugarcane bagasse ash (SCBA) obtained from high-temperature cogeneration boilers in concrete are highly limited. This study investigated the pretreatment process and optimization of SCBA collected from high-temperature boilers by various physicochemical methods. The effect of recalcination and grinding on the physical and mineralogical properties of SCBA were also examined. The percentage replacement of cement with SCBA was optimized using packing density and flow. The performance of optimized binder with combinations of cement and SCBA was validated through compressive strength of mortar specimens. From the results, it was observed that SCBA from high-temperature boilers can be used as a supplementary cementitious material with minimal processing efforts and a 15% level of replacement is suggested as the optimum level for SCBA-blended cement. Based on the investigation, a framework with a step-by-step procedure including pretreatment and optimization methods is suggested for the use of SCBA. © 2021 American Society of Civil Engineers.

Journal of Materials in Civil Engineering

Systematic Pretreatment Process and Optimization of Sugarcane Bagasse Ash Dosage for Use in Cement-Based Products

This study presents a novel digital control algorithm with state estimator technique for semi-active control of structures with magneto-rheological (MR) damper. The proposed control strategy is based on servomechanism (popularly known as command-following or tracking system), where the measured output of a system pursues the command of reference input. This is achieved through a hybrid proportional–integral (PI) controller, different from the conventional output or state-based feedback design, where the control force is proportional to the feedback of internal state (i.e., displacement and velocity) as well as the integral state (i.e., integral of output error signal) of the system. In this approach, optimal observer technique through Kalman filter is modified to estimate the full state and integral state vector of the system for feedback from the measured absolute acceleration output. Optimal gains of the proposed regulator (i.e., both proportional and integrator gains) and estimator are formulated by minimizing a desired performance index in discrete time. In addition, the present study proposes a direct algorithm, where the applied voltage to the MR damper varies continuously between the maximum and minimum range instead of being restricted to only maximum and minimum values. The adequacy of the proposed strategy is studied in terms of reduction in the following: (a) structural responses, (b) optimal control force, (c) sensor noise and process noise covariance of the filter output, and (d) applied voltage (as compared to clipped on–off case). Finally, it has been demonstrated that the proposed control algorithm provides superior performance and stability in comparison to the conventional proportional (state)-based techniques. © 2021 John Wiley & Sons, Ltd.

Structural Control and Health Monitoring

A novel servomechanism based proportional–integral controller with Kalman filter estimator for seismic response control of structures using magneto-rheological dampers