Department of Civil Engineering

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3D characterization of thermo-hydro-geological fields and estimation of power potential from Puga geothermal reservoir, Ladakh, India
(Elsevier, 2020-02) Jha, Shibani K
Puga geothermal reservoir in India shows promising thermal manifestation zones. However, no systematic study is done to develop the 3D characterization of thermo-hydro-geological fields for this reservoir. A new methodology is developed to characterize porosity, thermal conductivity, density, specific heat, radioactive heat capacity and permeability as 3D block heterogeneity till a depth of 4 km from resistivity maps. The temperature field and stored heat energy in a geothermal reservoir are dependent on these parameters. Based on the developed characterization, 3D coupled flow and heat transport processes are simulated to estimate the extractable temperature and power to be generated from doublet extraction scheme with various operational conditions. The study finds energy recovery factor of 8.16% and 37.83% and minimum electrical power potential of 1.2 MWe and 50.4 MWe with 12% conversion efficiency from the depths of 250 m and 1875 m respectively over 50 years from Puga field. Sensitivity for fluid injection/extraction rate and well spacing is studied. The results show promising power potential from 1.4 to 2 km of depth. The block heterogeneity characterization is more reliable than layered and homogeneous characterization. The outcomes would certainly acquire a significant role in decision-making strategies for Puga geothermal exploitation.
3D radar sounder simulations of geological targets on Ganymede Jovian Moon
(SPIE, 2019-10) Thakur, Sanchari
Subsurface investigation of the Jovian icy moons is expected to disclose interesting information on the Jovian system. The Radar for Icy Moon Exploration (RIME) is the instrument in charge of characterizing the subsurface of the three icy moons Ganymede, Europa and Callisto. To provide a key for interpretation for the real acquired data, simulations of different possible scenarios on Ganymede are presented in this work. In this paper, we present an approach to performance analysis of RIME based on the 3D modelling and electromagnetic simulations of selected icy moon targets. These simulations are carried out using the Finite-Difference Time-Domain (FDTD) technique, which has been used in recent years to support radar sounder applications. In this work, we analyze in detail some interesting targets: 1) the dark terrain regolith, 2) the bright terrain dielectric profile, and 3) the grooved bright terrain. Our analysis is performed in two levels. First, the contribution of individual features is analyzed, varying their geometry and composition to understand how the measured fields vary accordingly. Second, a more realistic geological arrangement of a combination of subsurface features is considered. The results are very promising and indicate that the subsurface response is detectable in most of the cases.
The 7th victor de mello goa lecture: climate resilient design of embankment using geocomposites
(Brazilian Association for Soil Mechanics and Geotechnical, 2025) Showkat, Rakshanda
Climate change is driving non-stationary rainfall patterns, intensifying both the frequency and magnitude of extreme precipitation events, which pose significant risks to earthen embankments. Traditional Intensity-Duration-Frequency (IDF) curves, based on stationary climate assumptions, often underestimate future hydrological loads. This study investigates the stability of embankments with and without geocomposite drainage layers under both stationary and non-stationary IDF scenarios, focusing on return periods of 10, 30, 50, and 100 years. Bengaluru, India, a monsoon-affected urban region, serves as the case study, with future rainfall projections derived from the CMIP6 SSP5-8.5 scenario to represent high-emission pathways. Numerical simulations reveal that unreinforced embankments under non-stationary conditions experience rapid pore-water pressure accumulation and a significant drop in Factor of Safety (FOS), reaching critical saturation in as little as 12 hours for 50-year return events. In contrast, geocomposite-reinforced embankments exhibit improved drainage, delayed saturation, and maintain FOS above 1.5 under stationary scenarios, and up to 18 hours of stability in the 100-year non-stationary case.
8 - Fly ash-incorporated recycled coarse aggregate-based concrete
(Elsiever, 2021) Barai, Sudhir Kumar
This chapter focuses on the feasible use of partial cement substituted by fly ash in 100% recycled coarse aggregate-based concrete (feasible use of fly ash in recycled aggregate concrete [FARAC]). The effect of particle packing method of mix proportioning is explored. Performance of such sustainable concrete is assessed for both strength and durability. At material level, this chapter examines fresh and hardened concrete properties. Microstructural analysis provides some insights for macrolevel behavior. Finer spherical fly ash particles and triple mixing method improve workability of recycled aggregate concrete (RAC). The negative effects of RAC on compressive strength (CS) is only significant at early ages (7 days), which reduces with adequate curing in RAC with 30% fly ash. Split tensile strength and the ratio of split tensile to CS decreases, which implies reduction of the rate of development of tensile strength at higher CS in RAC. Presence of fly ash in RAC causes densification of pores, thereby increasing the resistance to chemical attack. Fly ash used as cement substitution also proves to be beneficial as far as the creep and shrinkage of concrete is concerned. Adverse effects at material level can be accounted for with necessary design considerations for safe application of FARAC as structural components (beam, column, and slabs).
Abonyi, Janos 43 Alchanatis, Victor 159 Avineri, Erel 221 Ballerini, Lucia 149
(Springer, 2009) Barai, Sudhir Kumar
Contains a collection of papers that were presented at the 12th On-line World Conference on Soft Computing in Industrial Applications, held in October 2007
ABSTRACTS: International Conference on Sports Engineering,
(Excel Publisher, 2017-10) Gupta, Rajiv
Abundance, distribution patterns, and identification of microplastics in Brisbane River sediments, Australia
(Elsevier, 2020-01) Goonetilleke, Ashantha
Plastic pollutants in aquatic ecosystems have received wide attention and research endeavours since early 1970s. However, in comparison to marine environments, the occurrence of microplastics in a tidal river system remains largely unknown, especially in river sediments. Sediment samples taken from twenty-two sampling points along Brisbane River over the four different seasons revealed relatively high concentrations of microplastics in river sediments, with abundance ranging from 0.18 to 129.20 mg kg−1, or 10 to 520 items kg−1. Unfortunately, varied methods and units used for reporting do not allow the accurate comparison between related studies. The spatial distributions of microplastics hotspots indicated that microplastics abundance is distance-dominated caused by flow velocities. Lower and higher concentrations of microplastics abundance mostly occurred in dry and wet seasons, respectively. Significant temporal variations of microplastics concentrations was observed in residential and commercial areas. Polyethylene (PE), polyamide (PA) and polypropylene (PP), were the three main polymer types found in the Brisbane River sediments. Other polymer types such as polyethylene terephthalate (PET) were also detected. The majority of the detected microplastic particles were found to be <3 mm. This study reveals the abundance, spatial and temporal distribution patterns, and characteristics of microplastic pollutants in Brisbane River sediments, and provides systematic data for further research on microplastics in estuarine environments worldwide.
Accounting for temporal variability for improved precipitation regionalization based on self-organizing map coupled with information theory
(Elsevier, 2020-11) Guntu, Ravikumar
Precipitation regionalization deals with an investigation of the seasonality and its temporal variability and is useful for a wide variety of applications in hydro-meteorology. The d homogeneous regions can be used as a basis for transforming the information from gauged to ungauged sites and can reduce the uncertainty in estimating the seasonal characteristics of precipitation across India. Despite several studies stressing the importance of seasonality and temporal variability to the environment, there is a lack of studies on accounting for temporal variability in regionalization. Precipitation regionalization must account for both the precipitation magnitude and its temporal variability at multiple time-scales to extract the seasonality of a region representing coherent local and inter-annual variability. Therefore, in this study, we propose a framework for precipitation regionalization, considering both precipitation magnitude and its temporal variability. High resolution (0.25° × 0.25°) gridded daily precipitation time series over the period 1901–2013 from Indian Meteorological Department (IMD) was used for the evaluation of the framework. First, the historical daily time series was transformed into multiple time scales, i.e., annual, seasonal, and monthly time scales. Entropy-based standardized variability index was used to measure the inter-annual variability of precipitation at each time scale. Regionalization of grid points was performed using self-organizing maps, an artificial neural network. Ten distinct regions were identified that can be tied back to two general categories, such as climate characteristics and physical characteristics. Coupling of the self-organizing map with standardized variability index reveals unique seasonal distribution of precipitation for each region. The temporal evolution of clusters unravels a new emerging pattern across Central India. Consideration of temporal variability plays an insignificant role in the shape, size and stability of south-central India, south-eastern coastlines, and Konkan Coast. Intriguingly, separate Rain-belt and Rain-shadow Western Himalayas are formed due to the difference in topography and seasonal characteristics of precipitation. The temporal evolution of clusters unravels a significant change in the occurrence of the 50th percentile monsoon after the 1940s across the north-western region; a significant increase in the 50th percentile monsoon after the 1940s across western India, and decrease in the 50th percentile monsoon after the 1980s in the north-central Region.
Adoption of Ecohydrology Approaches for Urban Stormwater Management and Advancing the Circular Economy Concept
(CRC Press, 2024) Goonetilleke, Ashantha
Sustainable stormwater management is important to mitigate stormwater pollution as well as reuse stormwater resources. This chapter initially discusses the current environmental issues caused by stormwater pollution and the key challenges inherent in urban stormwater management. In response, ecohydrology proposes an innovative approach for urban stormwater management which can reduce urban flood risk, mitigate water pollution, protect habitats and biodiversity, and improve the aesthetics of the urban environment. Ecohydrology can be a key enabler for cities to achieve a circular economy as it can contribute to shifting from the linear to the circular management of stormwater resources in cities for realizing urban sustainability. To enable a circular economy, ecohydrology can be applied for sustainable stormwater management through restoring and maintaining the stormwater cycle, stormwater treatment and reuse, and nutrient recovery and reuse. Several recommendations are provided based on the current knowledge gaps in relation to the application of ecohydrology for urban stormwater management from a circular economy viewpoint.
Adsorption and mobility of metals in build-up on road surfaces
(Elsevier, 2015-01) Goonetilleke, Ashantha
The study investigated the adsorption and bioavailability characteristics of traffic generated metals common to urban land uses, in road deposited solids particles. To validate the outcomes derived from the analysis of field samples, adsorption and desorption experiments were undertaken. The analysis of field samples revealed that metals are selectively adsorbed to different charge sites on solids. Zinc, copper, lead and nickel are adsorbed preferentially to oxides of manganese, iron and aluminium. Lead is adsorbed to organic matter through chemisorption. Cadmium and chromium form weak bonding through cation exchange with most of the particle sizes. Adsorption and desorption experiments revealed that at high metal concentrations, chromium, copper and lead form relatively strong bonds with solids particles while zinc is adsorbed through cation exchange with high likelihood of being released back into solution. Outcomes from this study provide specific guidance for the removal of metals from stormwater based on solids removal.
Adsorption of heavy metals by road deposited solids
(IWA, 2013-06) Goonetilleke, Ashantha
The research study discussed in the paper investigated the adsorption/desorption behaviour of heavy metals commonly deposited on urban road surfaces, namely, Zn, Cu, Cr and Pb, for different particle size ranges of solids. The study outcomes, based on field studies and batch experiments, confirmed that road deposited solids particles contain a significantly high amount of vacant charge sites with the potential to adsorb additional heavy metals. Kinetic studies and adsorption experiments indicated that Cr is the most preferred metal element to associate with solids due to the relatively high electronegativity and high charge density of trivalent cation (Cr3+). However, the relatively low availability of Cr in the urban road environment could influence this behaviour. Comparing total adsorbed metals present in solids particles, it was found that Zn has the highest capacity for adsorption to solids. Desorption experiments confirmed that a low concentration of Cu, Cr and Pb in solids was present in water-soluble and exchangeable form, whilst a significant fraction of adsorbed Zn has a high likelihood of being released back into solution. Among heavy metals, Zn is considered to be the most commonly available metal among road surface pollutants.
Adsorption-desorption behavior of heavy metals in aquatic environments: influence of sediment, water and metal ionic properties
(Elsevier, 2022-01) Goonetilleke, Ashantha
Limited knowledge of the combined effects of water and sediment properties and metal ionic characteristics on the solid-liquid partitioning of heavy metals constrains the effective management of urban waterways. This study investigated the synergistic influence of key water, sediment and ionic properties on the adsorption-desorption behavior of weakly-bound heavy metals. Field study results indicated that clay minerals are unlikely to adsorb heavy metals in the weakly-bound fraction of sediments (e.g., r = −0.37, kaolinite vs. Cd), whilst dissociation of metal-phosphates can increase metal solubility (e.g., r = 0.61, dissolved phosphorus vs. Zn). High salinity favors solubility of weakly-bound metals due to cation exchange (e.g., r = 0.60, conductivity vs. Cr). Dissolved organic matter does not favor metal solubility (e.g., r = −0.002, DOC vs. Pb) due to salt-induced flocculation. Laboratory study revealed that water pH and salinity dictate metal partitioning due to ionic properties of Ca2+ and H+. Selectivity for particulate phase increased in the order Cu>Pb>Ni>Zn, generally following the softness (2.89, 3.58, 2.82, 2.34, respectively) of the metal ions. Desorption followed the order Ni>Zn>Pb>Cu, which was attributed to decreased hydrolysis constant (pK1 = 9.4, 9.6, 7.8, 7.5, respectively). The study outcomes provide fundamental knowledge for understanding the mobility and potential ecotoxicological impacts of heavy metals in aquatic ecosystems.
Advances in Computational Modeling and Simulation
(Springer, 2022) Srinivas, Rallapalli; Kumar, Rajesh
Advances in Concrete, Structural & Geotechnical Engineering
(Bloomsbury India, 2018) Singh, Shamsher Bahadur
Advances in Construction Materials and Management
(Springer, 2023) Singh, Shamsher Bahadur
This book presents the select papers from the proceedings of the National Conference on Advanced Construction Materials and Management (ACMM 2022). The book discusses the ongoing research and advanced practices in building materials and construction project management. Various topics covered in the book include new/alternate/supplementary construction materials, deterioration mechanisms in construction materials, microstructure characteristics of concrete, special and recycled aggregate concretes, advanced construction techniques, contracts and arbitration, building information modeling (BIM), prefabricated and modular construction, augmented reality (AR) and virtual reality (VR) in construction management, and artificial intelligence and machine learning in construction. The book is a useful reference for researchers and professionals working in the fields of construction materials and management.
Advances in Sustainable Construction Materials and Geotechnical Engineering
(Springer, 2020) Barai, Sudhir Kumar
Aggregate presaturation and concrete mixing technique for upscaling the use of fine recycled concrete aggregate
(Elsevier, 2025-06)
The porous structure of fine recycled concrete aggregate (FRCA) affects the properties of concrete and limits its use beyond 30 %. This study aims to improve the quality of concrete prepared with 100 % FRCA. Past work confirmed that the aggregate saturation level and concrete mixing methods influence the performance of FRCA concrete. To upscale the use of FRCA, a new modified presoaking method for mixing FRCA concrete is proposed, along with assessing the effect of three saturation levels (50 %, 75 %, and 100 %) and four mixing methods: conventional, presoaking, two-third presoaking, and modified presoaking. The compressive strength, flexural strength, static and dynamic modulus of elasticity, and the density of the interfacial transition zone (ITZ) were examined. Results showed that concrete with partially saturated FRCA exhibited better mechanical properties. The modified mixing method provided consistent results and an ITZ with lesser void content, indicating higher reliability than the conventional, presoaking, and two-third presoaking methods. At a 50 % saturation level of FRCA, the results for the modified presoaking method showed higher compressive strength, flexural strength, static, and dynamic modulus by 10 %, 9 %, 12 %, and 20 %, respectively, in comparison to concrete mixed by a conventional method consisting of 100 % saturated FRCA. This work provides clarity on appropriate processes and practices for the utilization of FRCA in concrete and facilitates a circular economy in the construction industry.
Aging Resistance of Bitumen Modifiers: A Comprehensive Review
(ASME, 2023-09) Kakade, Vijay B.
The deterioration of physical and mechanical properties of bituminous materials that are attributable to the aging of bitumen is one of the major causes of reduction in service life of flexible pavements. Thermal-oxidation and photo-oxidation aging are the two major types of aging of bitumen. Heat and oxygen cause thermal-oxidative aging, whereas ultraviolet irradiation and oxygen causes ultraviolet photo-oxidative aging of bitumen. Aging of binder leads to significant changes in the chemical composition of bitumen resulting in reduction of cracking resistance of bituminous mixes because of hardening of bitumen. So, it is quintessential to reduce the rate of hardening of bitumen induced by aging for prevention of premature failure of flexible pavements. The type of bitumen used for production of bituminous mixes have a significant effect on aging resistance of bitumen. The bitumen can be modified by using different types of modifiers such as antioxidants, bio-oils, nanomaterials, polymers, rubber, and ultraviolet absorbers. In addition to this, the modifiers such as fillers, warm mix additives, and rejuvenators also affect the aging resistance of bitumen. However, the effectiveness of these modifiers in preventing the hardening of bitumen because of aging varies with type of aging. The modifiers that exhibit improvement in thermal-oxidative aging resistance of bitumen are found to be less effective in improvement in photo-oxidative aging resistance and vice-versa. So, it is imperative to understand the effectiveness of different types of bitumen modifiers for the prevention of thermal-oxidative and photo-oxidative aging of bitumen. This review documents the resistance of different types of modifiers to thermal-oxidative and photo-oxidative aging. Finally, the scope for future work based on the critical gaps identified from existing works is also provided to assist further research.
Agricultural watershed conservation and optimization using a participatory hydrological approach
(Springer, 2024-07) Srinivas, Rallapalli
Maximizing the impact of agricultural wastewater conservation practices (CP) to achieve total maximum daily load (TMDL) scenarios in agricultural watersheds is a challenge for the practitioners. The complex modeling requirements of sophisticated hydrologic models make their use and interpretation difficult, preventing the inclusion of local watershed stakeholders’ knowledge in the development of optimal TMDL scenarios. The present study develops a seamless modeling approach to transform the complex modeling outcomes of Hydrologic Simulation Program Fortran (HSPF) into a simplified participatory framework for developing optimized management scenarios. The study evaluates seven conservation practices in the Pomme de Terre watershed in Minnesota, USA, focusing on sediment and phosphorus pollutant load reductions incorporating farmers’ opinions to guide practitioners toward implementing cost-effective CPs. Results show reduced tillage and filter strips are the most cost-effective practices for non-point source pollution reduction, followed by conservation cover perennials. The integration of SAM with HSPF is crucial for sustainable field-scale implementation of conservation practices through enhanced involvement of amateur-modeling stakeholders and farmers directly connected to fields.
Air Quality Forecaster: Moving Window Based Neuro Models
(Springer, 2009) Barai, Sudhir Kumar
The present paper aims to demonstrate neural network based air quality forecaster, which can work with limited number of data sets and are robust enough to handle air pollutant concentrations data and meteorological data. Performance of neural network models is reported using novel approach of moving window concept for data modelling. The performance of model is checked with reference to other research work and found to be encouraging.