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

The choice of reference evapotranspiration (ETo) estimation methods and general circulation model (GCM) are crucial for projecting water deficit under a changing climate. Standardized Precipitation Evapotranspiration Index (SPEI) derived from water deficit also varies with the choice of GCM and ETo estimation methods. In this study a variance-based global sensitivity analysis was used to estimate relative sensitivity of projected changes in future water deficit (P-ETo) and SPEI to the choice of GCM and ETo estimation methods over parts of the Indian subcontinent. For evaluating the change in water deficit and droughts, 7 GCMs and 11 ETo methods were analyzed for two distinct periods i.e. 2030-2060 and 2070-2100 compared to the baseline (1951-1980). The 11 ETo methods were grouped into 4 major categories namely based on temperature, radiation, mass transfer and combination methods. Moreover, based on the ETo categories, a non-parametric Mann-Whitney was performed to quantify robust changes under a warming climate. Results show that changes in future water deficit and droughts varies with regions and seasons. Overall, changes in water deficit droughts are more inclined to the choice of ETo method, while the GCM-ETo interaction effects are more prominent in some regions. Results also showed that within an individual ETo category, individual ETo methods do not necessarily agree on the magnitude/direction of change in projecting water deficit and SPEI for future conditions. This has important implications towards selection of appropriate ETo estimation for drought analysis in data scarce regions under a changing climate. Results of this study indicate, the role of proper ensemble formation of GCMs and ETo estimation methods based on seasons and regions, to develop a robust range of future conditions for water resources planning.

World University root node

American Geophysical Union, Fall Meeting 2020

Uncertainty in Future Projections of Water Deficit Droughts Based on Evapotranspiration Methods in the Indian Subcontinent

The current study analyzes the changes in the climate pattern of Bharathapuzha river basin in Kerala, India, which experiences a significant imbalance in water availability since 1990. The analysis of the climatic variables shows that there are three climatic zones existing in the basin. The trend in the historic climatic variables is estimated using the non-parametric Mann-Kendall test and the Sen slope analysis. A discrete wavelet analysis is also performed to separate only the long period component of the signal, and its trend is also studied. A significant decreasing trend is observed in the rainfall. However, a monotonous long-term increasing trend is detected for monthly average temperatures and monthly minimum temperatures. The sequential Mann-Kendall test result shows a significant change in the climatic pattern after 1980. The rainfall effectiveness of the basin is analyzed using indices. A drought analysis is also conducted using Standardized Precipitation Index (SPI) in different time scales since climatic zones 2 and 3 in the catchment are drought-prone areas in recent years. A detailed analysis on the existence of climate change in this region is conducted for the first time. These results can be further used for planning and development of climate change adaptation policies for the basin.&nbsp;

Theoretical and Applied Climatology

Long-term changes in climatic variables over the Bharathapuzha river basin, Kerala, India

International Conferences

Removal and recovery of nutrients and simultaneous generation of electricity from urine

Mechanically stabilized earth structures with alternate backfills for highway structures

BMS are deployed to manage buildings such as Shopping malls, office, and residential complexes. However, the information needed for their efficient functioning are either incomplete, generated separately, or hard to determine. BIM generates and stores useful integrated information during design and construction phases of the building projects. These Information are well utilized during design and construction stages but their usage in FM stage is limited. The guidelines and standards to facilitate BIM model during design and construction stages, are not considered critically usable. Hence, this paper aims to identify the need for crucial asset information during FM practices while executing the BMS process, to develop a standard framework for information specifications during the early development of BIM model, and utilize the same as a source for BMS in FM processes. Nevertheless, this paper addresses the common FM practices and its building data requirements towards efficient BMS implementation pivotal to the mechanical and electrical systems for a conceptual framework of a BIM model. The research adopts deductive approach through semi-structured qualitative interviews with FM stakeholders of the malls in Saudi Arabia to obtain the standard FM data requirement from client perspective, while managing the FM process through a BMS system. © IEOM Society International.

Proceedings of the International Conference on Industrial Engineering and Operations Management

A review on current status of facility management practices in building industry and prospective bim intervention to manage the facilities effectively during its service life

The objective of this research was to develop and evaluate asphalt-rubber gap-graded (AR-Gap) mixtures produced with varying gap aggregate gradations and designate a suitable aggregate gap gradation for local conditions, which could further be implemented at global level after necessary laboratory and field evaluations. A total of fifteen gap gradations were investigated, including seven specified by various highway agencies and eight trial gradations. The gradation studies recommended clustering seven gradations into two groups of similar characteristics. Furthermore, investigations on trial gradations presented the significance of each portion of the aggregate gradation in developing a superior performing gap gradation. Based on the refined gradation studies, three gap gradations were chosen: two from agency-specified, and one from the trial gradation for basic performance evaluation. Rutting, fatigue cracking, and moisture susceptibility investigations were accomplished on ten asphalt mixtures encompassing nine AR-Gap mixtures and one conventional dense graded mix. The results depicted superior performance of the proposed gradation indigenously developed in this study in respect of all distresses. The balance of coarse and fine aggregates in the proposed gradation facilitated higher strength at higher temperatures to resist rutting. Furthermore, the customized AR binder aided in providing additional resilience to the mixture, thereby improving the fatigue cracking resistance of the proposed AR-Gap mixture. Overall, it is envisaged that this study will help understand the effect of aggregate gradation characteristics on the performance of the AR-Gap mixture and aid in the development of AR-Gap mixtures as suitable long-lasting pavements. Copyright © 2018 by ASTM International

Journal of Testing and Evaluation

Development and performance analysis of asphalt-rubber gap-graded mixtures: Study on aggregate gradations

The objective of this study was to evaluate the rutting performance of asphalt-rubber gap-graded (AR-Gap) mixtures using wheel tracking tests and further explain the permanent deformation characteristics of those special materials through statistical and reliability approaches. A total of 28 asphalt mixtures covering over 200,000 data points were utilised, including: 27 AR-Gap mixtures and one conventional dense-graded (DG) mixture. Statistical analysis confirmed the significance of binder type, aggregate gradation, and binder content on the superior rutting resistance of AR-Gap mixtures than the DG mix. Selection of the best combination of all the three variables resulted in a significantly rut-resistant AR-Gap mixture. Reliability analysis on mixtures’ rutting performance was accomplished using Weibull distribution function. Weibull model parameters and derived factors aided in a better interpretation of the rutting performance of AR-Gap mixtures. Overall, it is envisaged that this research study would further the state-of-the-art in designing rut-resistant asphalt-rubber gap-graded mixtures. © 2019 Informa UK Limited, trading as Taylor & Francis Group.

Road Materials and Pavement Design

Rutting performance of asphalt-rubber gap-graded mixtures: evaluation through statistical and reliability approaches

Landfill cover barriers are susceptible to flexural distress due to the differential settlements caused by biodegradation and heterogeneous composition of the underlying waste. The effect of discrete fibre inclusions on the flexural distress of landfill cover barriers was studied using centrifuge model tests. Three types of fibres were used: polyester (PET), polypropylene-tape (PP-T) and polypropylene-fibrillated (PP-F). For unreinforced barriers (UB), the crack initiation and water breakthrough were observed at low distortion levels compared to identical fibre-reinforced barriers (FB). The strain at crack initiation and strain at water breakthrough for FB was 2.36 times and 2.76 times higher than identical UB, respectively. Also, suppression of the cracks and improved water tightness was observed due to the overburden pressure in both UB and FB. PET fibre-reinforced barriers were found to be superior in maintaining the water tightness of the barrier compared to PP-T and PP-F fibres used in the present study. Propagation of cracks penetrating through the thickness of the soil barrier was significantly restrained by the fibres irrespective of the fibre type. Scanning electron micrographs of exhumed fibres indicated that the fibres in the present study were distorted and participated in taking tension due to differential settlements. © 2020 Thomas Telford Ltd

Geosynthetics International

Influence of fibre morphology on the integrity of geofibre-reinforced soil barriers

Mechanistic-empirical design of flexible pavement AASHTO practice requires resilient characteristics of sub grade soil. Though the resilient modulus is assumed to account for plastic strain accumulation, some subgrade soils with more fine content undergo excessive plastic deformation under repeated loads even though they have remarkable resilient properties. Hence permanent deformation is also an important parameter which should be considered in the design process. In the present study, permanent deformation behaviour of clayey subgrade soil with intermediate compressibility is studied using repeated load triaxial tests. The influence of confining pressure, moisture content and deviator stress levels on the permanent deformation behaviour is examined. The transition of the soil sample from stable to unstable state can be observed and critical stress levels established with the help of shake down theory. Two regression models reported in the literature, Power law model and VTT model, are used to predict the plastic strains with a number of load cycles and stress levels as the variables. © 2018, © 2018 Informa UK Limited, trading as Taylor & Francis Group.

European Journal of Environmental and Civil Engineering

Resilient and permanent deformation behaviour of clayey subgrade soil subjected to repeated load triaxial tests

Flow connectivity in the hillslope–riparian–stream (HRS) system describes the hydrological linkage between upland water and the channel network. However, the time and form of the establishment of HRS connectivity are not adequately understood. Herein, we examined how hillslope structure (topography and soil) and rainfall influence HRS connectivity in a steep, forested, zero-order catchment at the Hemuqiao Hydrological Experimental Station in Southeast China, from July 2016 to November 2017. To this end, surface and subsurface flow, soil moisture, and soil hydraulic conductivity (Ks) were observed, and soil dye staining experiments were conducted. Two patterns of HRS connectivity, namely saturation connectivity that initiates at the soil–bedrock interface (SCSB) and saturation connectivity at different soil horizons (SCSH), were identified. The persistence time of SCSH connectivity was short (&lt;1 h), and the contribution of the perched interflow in different soil horizons to the total runoff was relatively small (0.6–3.0%). Instead, we found that the soil–bedrock interface acted as an important impeding layer that established HRS connectivity. That is, among the rainfall events during which HRS connectivity was established, 90% were established through SCSB connectivity and only 10% were established through SCSH connectivity. We further evaluated the time required to established HRS connectivity and found that SCSB connectivity required more time (4.6–67.4 h) than SCSH connectivity (&lt;1 h). We further found that rainfall intensity determined the initiation of connectivity and that the time required for HRS connectivity decreased exponentially with increasing rainfall intensity (R2 = 0.67). Finally, we found that subsurface saturation excess flow, rather than Hortonian overland flow, was the main contributor to the flood peak during large events. In these events, the total volume of the runoff and flood peak were five and eight times higher than that of subsurface outflow, respectively. These results provide a clearer understanding of runoff generation and can narrow the gap between experiments and models for further development of hydrological theories and methods. © 2020 Elsevier B.V.