Department of Civil & Infrastructure Engineering

&ldquo;IIT Jodhpur is committed to impart quality education to facilitate the creation of qualified, competent and responsible human resources to meet the emerging technological challenges of the world. It is working towards creating an equitable learning platform that is positive, accessible and effective in the face of the modern societal and scientific advancements.

Flexibility in curriculum, in all its academic programs, encompassing elements of teaching, research, creativity, innovation and entrepreneurship is the most unique feature of IIT Jodhpur. The Department of Science and Technology (DST), under the National Mission on Cyber Physical Systems, has identified IIT Jodhpur as a Technology &amp; Innovation Hub in the area of Augmented Reality and Virtual Reality. The institute has also been nominated as the coordinator for the Jodhpur City and Knowledge Cluster by the Office of Principal Scientific Adviser, Government of India.

The sprawling 852-acre IIT Jodhpur campus is a majestic tribute to the deep-rooted diverse cultural heritage of the region. The campus is an architectural masterpiece, which is slated to become an international exemplar of sustainability with net-zero energy, and advanced water and waste management strategies.&rdquo;

IIT Jodhpur

Analysis and Modeling of Climate Change Impact on Hydrological Extreme Events across India

World University root node

Variation in porous media compositions influence the co-transport behavior of ZnO and FexOy mixed nanoparticles

The sensitive ecosystem of the central Himalayan (CH) region, which is experiencing enhanced stress from anthropogenic forcing, requires adequate atmospheric observations and an improved representation of the Himalaya in the models. However, the accuracy of atmospheric models remains limited in this region due to highly complex mountainous topography. This article delineates the effects of spatial resolution on the modeled meteorology and dynamics over the CH by utilizing the Weather Research and Forecasting (WRF) model extensively evaluated against the Ganges Valley Aerosol Experiment (GVAX) observations during the summer monsoon. The WRF simulation is performed over a domain (d01) encompassing northern India at 15 km-15 km resolution and two nests (d02 at 5 km-5 km and d03 at 1 km-1 km) centered over the CH, with boundary conditions from the respective parent domains. WRF simulations reveal higher variability in meteorology, e.g., relative humidity (RHD70.3 % 96.1 %) and wind speed (WSD1.1 4.2ms-1), compared to the ERA-Interim reanalysis (RHD80.0 % 85.0 %, WSD1.2 2.3ms-1) over northern India owing to the higher resolution. WRF-simulated temporal evolution of meteorological variables is found to agree with balloon-borne measurements, with stronger correlations aloft (r D0.44 0.92) than those in the lower troposphere (r D0.18 0.48). The model overestimates temperature (warm bias by 2.8 C) and underestimates RH (dry bias by 6.4 %) at the surface in d01. Model results show a significant improvement in d03 (P D827.6 hPa, T D19.8 C, RHD92.3 %), closer to the GVAX observations (P D801.4 hPa, T D19.5 C, RHD94.7 %). Interpolating the output from the coarser domains (d01, d02) to the altitude of the station reduces the biases in pressure and temperature; however, it suppresses the diurnal variations, highlighting the importance of well-resolved terrain (d03). Temporal variations in near-surface P, T , and RH are also reproduced by WRF in d03 to an extent (r&gt;0:5). A sensitivity simulation incorporating the feedback from the nested domain demonstrates the improvement in simulated P, T , and RH over the CH. Our study shows that the WRF model setup at finer spatial resolution can significantly reduce the biases in simulated meteorology, and such an improved representation of the CH can be adopted through domain feedback into regional-scale simulations. Interestingly, WRF simulates a dominant easterly wind component at 1 km-1 km resolution (d03), which is missing in the coarse simulations; however, the frequency of southeasterlies remains underestimated. The model simulation implementing a highresolution (3 s) topography input (SRTM) improved the prediction of wind directions; nevertheless, further improve- ments are required to better reproduce the observed localscale dynamics over the CH. © 2021 EDP Sciences. All rights reserved.

School of Liberal Arts (SoLA)

Fulltext

Geoscientific Model Development

Effects of spatial resolution on WRF v3.8.1 simulated meteorology over the central Himalaya

In this paper, we explore the instability of large-scale riverbed patterns, performing a linear stability analysis of a zero-pressure gradient free-surface flow in a wide straight channel with an erodible bed. The local depth-averaged turbulence state is governed by two key parameters: Namely, the turbulent kinetic energy (TKE) and its dissipation rate. A depth-averaged flow model coupled with the transport equations of the TKE and its dissipation rate and the particle transport model are developed to examine the formation of large-scale patterns. Both the modes of particle transport as bedload and suspended load are considered herein, allowing for the extension of the conventional theories to cover from hydraulically smooth to transitional flow regimes. The classical Exner equation of the bed evolution is modified in the presence of suspended particles, whose concentration is coupled with the steady-state advection-diffusion equation. Applying a standard linearization technique, the periodic perturbations in both streamwise and spanwise directions are imposed on the bed to find the dispersion relationship. The stability maps for the growth rate of large-scale patterns are obtained as a function of streamwise and spanwise wavenumbers and of key parameters associated with the flow and particles. © 2021 Author(s).

Physics of Fluids

Instability of large-scale riverbed patterns

Dunes and antidunes on sand and gravel streambeds propagate with a finite speed, with dunes propagating downstream and antidunes propagating both upstream and downstream. Existing linear stability theories predict the dune propagation reasonably well. However, in light of the experimental data, they fail to accurately predict the directional preference of antidunes. We revisit the problem by employing a one-equation rotational-flow model. For bedload-dominant streams, the phase lag between the sediment flux and the local bed topography is the central mechanism causing the instability. We find a clear signature of the non-propagating perturbation within the unstable region of antidunes, separating the upstream and downstream propagating antidunes. The present model offers a unique reconstruction of the linear stability map, capturing satisfactorily the experimental data of dunes, antidunes, and the transition from dunes to antidunes. © 2021 Author(s).

Linear stability of dunes and antidunes

Regularized continuum damage models such as those based on an order parameter (phase field) have been extensively used to characterize brittle damage of compressible elastomers. However, the prescription of the surface integral and the degradation function for stiffness lacks a physical basis. In this article, we propose a continuum damage model that draws upon the postulate that a damaged material could be mathematically described as a Riemannian manifold. Working within this framework with a well-defined Riemannian metric designed to capture features of isotropic damage, we prescribe a scheme to prevent damage evolution under pure compression. The result is a substantively reduced stiffness degradation due to damage before the peak response and a faster convergence rate with the length scale parameter in comparison with a second-order phase field formulation that involves a quadratic degradation function. We also validate this model using results of tensile experiments on double notched plates. © 2021 by ASME.

Journal of Applied Mechanics, Transactions ASME

A geometrically inspired model for brittle damage in compressible elastomers

This paper presents a preliminary experimental and numerical investigations on the axial compressive capacity of cold-formed steel of square hollow section (SHS) stub columns having central circular perforations. The stub columns were prepared from commercially available structural tubular steel members - Tata Structura-YSt 310 manufactured by Tata Steel India. Stub columns having various diameter of perforation to flat web width ratios, d/w ~ 0.1 to 0.9, were considered. Finite element (FE) models were developed to determined ultimate capacities of perforated columns, which were not included in the experiment procedure, via carefully validated FE procedure, using commercial FE software Abaqus. Based on the study, a near non-linear drop in the ultimate load capacity of perforated columns as the perforation size increases was observed. Further, column capacities predicted by design code and proposed equations in the literatures are compared with the test and FE ultimate column capacities and found that most of the design equations provided overly conservative and highly scattered predictions. Copyright © 2018 by The Hong Kong Institute of Steel Construction.

Proceedings of the 9th International Conference on Advances in Steel Structures, ICASS 2018

Capacity of cold-formed steel hollow stub columns with central circular perforations

Summer monsoon (June-September) precipitation is crucial for agricultural activities in India. Extremes during the monsoon season can have deleterious effects on water availability and agriculture in the region. Here, we show that hot and dry extremes during the summer monsoon season significantly impact food production in India and find that they tend to occur during El Ni{\~{n}}o years during the observed record of 1951–2018. We then use an ensemble of climate simulations for the historic (1971–2000) and future (2006–2100) that capture this coupling between El Ni{\~{n}}o and the Indian monsoon to show that the frequency of concurrent hot and dry extremes increases by a factor of 1.5 under continued greenhouse warming during the 21st century. Despite projections of summer monsoon intensification on the order of $\sim$10%, the rise in surface air temperatures as well as increase in rainfall variability contributes to more severe hot and dry monsoon extremes over India, thereby posing a substantial challenge to future food security in India.

npj Climate and Atmospheric Science

Future exacerbation of hot and dry summer monsoon extremes in India

In the recent past, geotechnical applications of CCR is the major focus area in the construction industries. However, the economics of a project and environmental safety are some of the key issues, that still need to be addressed. This research work focusses on the comprehensive assessment of the economic and ecological sustainability of bulk utilization of CCR in geotechnical applications. Physical, mechanical, and physicochemical properties of different types of CCR were determined and compared with locally available natural soil. The results reveal that all CCR samples were non-plastic, exhibited low sensitivity to moisture content, negligible crushing during compaction, and displayed significant shear strength (φ ≥ 30°). All CCR demonstrated an alkaline pH that satisfied the requirements of a fill material. The environmental risk associated with the application of CCR was assessed through leachability tests as per EN 124057–4 (2002). The results revealed that CCR is safe for disposal in inert landfills as per European Council Decision 2003/33/EC guidelines, due to low risk to the environment. The cost estimation suggests that CCR is comparably very economical if available within 5 km of a construction site. The findings of the study clearly revealed that the application of CCR is cost-effective as well as environmentally safe and a sustainable alternative to the natural soil. © 2020 Elsevier Ltd

Journal of Cleaner Production

Comprehensive assessment of cleaner, sustainable and cost-effective use of coal combustion residue (CCR) in geotechnical applications

Francisco Nicolás Cantero-Chinchilla, Ph.D. Research Fellow, Soil and Water Div., IAS-CSIC, Spanish National Research Council, Alameda del Obispo s/n, C´ordoba 14004, Spain (corresponding author). ORCID: https://orcid.org/0000-0003-3492-6752. Email: fncantero@ias.csic.es; z12cachf@uco.es Oscar Castro-Orgaz, Ph.D. Professor, Hydraulic Engineering Area, Univ. of Cordoba, Cordoba 14071, Spain. Email: ag2caoro@uco.es Subhasish Dey, M.ASCE Professor, Dept. of Civil Engineering, Indian Institute of Technology Kharagpur, Kharagpur, West Bengal 721302, India; Distinguished Visiting Professor, Dept. of Hydraulic Engineering, State Key Laboratory of Hydro- Science and Engineering, Tsinghua Univ., Beijing 100084, China. Email: sdey@iitkgp.ac.in https://doi.org/10.1061/(ASCE)HY.1943-7900.0001608 In the original paper, the following reference is incorrect: Sarno, L., A. Carravetta, R. Martino, and Y. C. Tai. 2011. “A twolayer approach to describe granular flows over rough surface.” In Proc., 35th National Conf. on Theoretical and Applied Mechanics. This shall be replaced by the following reference: Sarno, L., A. Carravetta, R. Martino, and Y. C. Tai. 2013. “Pressure coefficient in dam-break flows of dry granular matter.” J. Hydraul. Eng. 139 (11): 1126–1133. https://doi .org/10.1061/(ASCE)HY.1943-7900.0000772. All throughout the text of the paper, Sarno et al. (2011) is to be read as Sarno et al. (2013), including the reference cited in Fig. 5. © 2020 American Society of Civil Engineers (ASCE). All rights reserved.

Journal of Hydraulic Engineering

Erratum: Prediction of Overtopping Dike Failure: Sediment Transport and Dynamic Granular Bed Deformation Model (J. Hydraul. Eng DOI: 10.1061/(ASCE)HY.1943-7900.0001608)