Civil Engineering

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Journal of Hazardous, Toxic and Radioactive Waste

Climate Change and Sustainable Water Resources Management

Well foundation is commonly used in India for road and railway bridges over rivers. It is a massive structure and hence it is generally considered to be safe under laterally loaded condition. Indian Roads Congress Codes (IRC:45-1972 and IRC:78-1983) suggests limit equilibrium approach to determine lateral load capacity of well foundation. It considers well foundation as a rigid body and surrounding soils as elastic in design state and plastic in limit state. Design procedure stated in Indian standard codes determines ultimate lateral load capacity of Well-Soil system. However, it does not yield the magnitude of lateral displacement of a well foundation at the ultimate load. Because of this, it is difficult to decide whether the lateral displacement at estimated ultimate lateral load capacity of a well foundation is allowable or not. Over the years, few methods to analyze the lateral response (both force and displacement responses) of well foundation are developed. These methods consider surrounding soil as linear elastic material which is modeled by linear elastic springs, and well foundation as a rigid body. Recently developed methods consider lateral stiffness as well as rotational stiffness of the surrounding soil and represent soil by parallel combination of lateral linear springs and rotational springs. Some of these methods also consider flexibility of well foundation and model well foundation by Euler-Bernoulli beam element. In this article, we present a comparative study of the available methods of analysis of laterally loaded well foundation. This study indicates significant differences in the response of Well-Soil system obtained from different methods. Validation of existing methods is done with two-dimensional continuum model to identify accuracy in existing models. It highlights the need for proper evaluation of available methods of analysis with realistic incorporation of foundation stiffness and interface effect in modeling the Well-Soil system for pseudo static loading conditions. © Springer Nature Singapore Pte Ltd 2020.

Lecture Notes in Civil Engineering

Comparative study of methods for analysis of laterally loaded well foundation

This paper presents critical assessment of codal provisions to determine lateral stability of a well foundation. A two-dimensional finite element model of soil–well foundation system is developed for this study. The well foundation is modeled as a linear elastic body, whereas the soil as a nonlinear elasto-plastic material which is defined using multi-yield surface plasticity model. Interface between the well foundation and the adjoining soil is defined using constitutive relationships describing relative sliding and separation at the interface. Assumptions considered in the existing codal provisions to determine lateral stability of a well foundation are evaluated in light of the results obtained from the present study. The present study shows that the mechanism of deformation of laterally loaded soil–well foundation system obtained in this study differs from that considered in the existing codal provisions. It is observed that the existing codal provisions overestimate the lateral load capacity of a well foundation. © 2020, Indian Geotechnical Society.

Indian Geotechnical Journal

An Assessment of Codal Provisions for Analysis of Laterally Loaded Well foundations

To characterize the polycyclic aromatic hydrocarbons (PAHs) in PM2.5 (particles with an aerodynamic diameter ≤ 2.5 µm) in Delhi, the national capital of India and one of the most polluted megacities in the world, we conducted a comprehensive field campaign at six sampling sites in different areas during winter and summer. Both the PM2.5 and PAH concentrations exhibited seasonal variations, with higher values during winter (356 ± 136 µg m–3 and 75.1 ± 50.2 ng m–3 for the PM2.5 and PAHs, respectively) than summer (268 ± 94 µg m–3 and 10.4 ± 8.5 ng m–3, respectively). Additionally, the maximum winter concentrations were found in the urban industrial-cum-residential area (430 ± 104 µg m–3 and 124.5 ± 70.7 ng m–3 for the PM2.5 and PAHs, respectively). Among the PAHs, benzo[ghi]perylene displayed the highest ambient concentration (14.3 ± 7.4 ng m–3 during winter), followed by indeno[1,2,3-cd]pyrene (13.1 ± 7.3 ng m–3 during winter), at the majority of the sampling sites. Additionally, based on the benzo[a]pyrene-equivalent concentrations at the six sites, we estimated the PAH-associated incremental lifetime cancer risk (ILCR) in the entire study area to be 423 per 1 million persons, which exceeds the World Health Organization (WHO) limit. Source apportionment performed with the Chemical Mass Balance Model version 8.2 (CMB8.2) revealed that emissions from vehicles, municipal waste burning and biomass burning contributed 62\%, 15\% and 11\% to the total PAH mass, respectively. Our results indicate that PM2.5-bound PAHs in Delhi will continue to pose serious health risks without collective initiatives for pollution control from scientific, policy-making and regulatory bodies. ©The Author(s).

Aerosol and Air Quality Research

Spatio-seasonal concentrations, source apportionment and assessment of associated human health risks of pm2.5-bound polycyclic aromatic hydrocarbons in delhi, india

Abstract: The emerging demand of natural indigo dye due to the environmental and sociological concerns imparted by the synthetic dye helps in leveraging the conventional natural indigo dye production process in many developing countries, including India. Despite having remarkable global market potential, the high price of natural indigo dye impedes its extensive commercialization. Therefore, in the present study, the economics of natural indigo dye is evaluated through life cycle cost (LCC) analysis by considering the traditional indigo dye production process in India using the plant biomass Indigofera tinctoria L. The life cycle model includes cultivation of Indigofera biomass, as well as the production and processing of indigo dye and the cost involved in each step. Along with the detailed cost analysis, the present study also includes socio-economic analysis and possibilities of cost reduction based on the outcome of sensitivity analysis. From the LCC analysis, the life cycle cost of Indigofera biomass cultivation is $420.74 ha−1 year−1, whereas the indigo dye production cost is $113 ton−1 of Indigofera biomass. For an annual dye production of 1000 tons, the present study estimated the economic stabilization of rural farmers and labours by an annual employment generation of 196,250 man-days year−1 and 12,50,000 man-days year−1, respectively. By sensitivity analysis, the raw material price was identified as the major contributor in the total indigo dye production cost. As a cost reduction measure, the combination of biomass yield (70 tons) and reduction in the biomass production cost (50\%) was found to be suitable. Utilization of by-product generated from the dye industry into value-added products could contribute towards a cost reduction of 22\% in the Indigofera biomass cultivation and a cost saving of $37.4 ton−1 of biomass in the indigo dye production cost. Graphic Abstract: [Figure not available: see fulltext.]. © 2020, Springer-Verlag GmbH Germany, part of Springer Nature.

Clean Technologies and Environmental Policy

Life cycle cost analysis of natural indigo dye production from Indigofera tinctoria L. plant biomass: a case study of India

Unsafe road crossing behavior by pedestrians is a main contributing factor of pedestrian casualties. Data from 2006 to 2012 in Delhi, India, show that pedestrians have the largest share in total road fatalities. Although facilities such as underpasses and overpasses are often provided to help cross a road, most often, pedestrians do not use them. Pedestrian perceptions play an important role in the use of such facilities. This study examined the relationship between actual crash risk and perceived risk for selecting crossing facilities by pedestrians. The road crossing preferences of pedestrians were analyzed for midblocks, intersections, and locations with a flyover where overpasses and underpasses are provided for road crossing. Responses covering safety and convenience of using specific facilities from one thousand pedestrians were collected through a structured questionnaire on selected locations. A path analysis model, i.e., a special case of structural equation modeling, was developed for analyzing the data. Results show that an inverse relationship exists between actual and perceived crash risks. Crossing behavior in midblocks was found to mediate this relationship. At locations with a flyover, the perspective of convenience was significantly related to the actual crash risk. This study identifies the potentially useful roles that pedestrian perceptions of risk and preferences in road crossing can play in avoiding actual crashes involving pedestrians. Pedestrians’ demographics was also analyzed with perceived risks and preferences for road crossing. From a policy standpoint, the relationships identified between actual and perceived risk and the built environment features of road crossing provide useful information for transportation planners, city planners and engineers. Since perceived risk influences travel behavior, it is important to study influence of perceived crash risk for pedestrians. Proactive interventions are required at the locations with low crash rates as the perceived risk by pedestrians is quite high at these places. This is in addition to the measures required at the locations associated with high actual crash risk faced by pedestrians though these locations are having low perceived crash risk. © 2020 Hong Kong Society for Transportation Studies

Travel Behaviour and Society

Influence of actual and perceived risks in selecting crossing facilities by pedestrians

This paper presents, the effect of soil spatial variability on response of laterally loaded well foundation embedded in linear elastic soil medium. The spatial variation of elastic modulus of soil along embedment depth of the foundation is modeled using random field theory. Elastic modulus of soil is considered to be random variable that follows Log-Normal probability distribution. Monte Carlo simulation technique is used to generate various random realization of spatial variability of elastic modulus of soil. Random realization is done for different values of coefficient of variation of elastic modulus with different spatial correlation distance. A finite element model is developed for laterally loaded well foundation embedded in linear soil. The finite element model is then coupled with the random field of elastic modulus of soil to analyze effect of soil spatial variability on the response of well foundation under different values of lateral load. The results obtained from this study indicate that spatial variation of soil elastic properties has small effect on lateral response of well foundation irrespective of magnitude of lateral load. © Springer Nature Singapore Pte Ltd. 2020.

Effect of soil spatial variability on lateral response of well foundation embedded in linear elastic soil

This study investigates spatio-temporal paradigm of the impact of road networks on urban ecosystem dynamics (UED) by analysing the composition and configuration of land use land cover (LULC) and land surface temperatures (LST) derived from Landsat data for the years 2000 and 2017. The results indicate a positive association between road network and built-up land showing higher concentration of built-up land closer to the road network. This increase in grey infrastructure has led to an increase in the maximum LST by 6 °C to 7.5 °C along primary and tertiary roads, whereas 4 °C to 5 °C along secondary roads. Rapid intensification of road network along with the associated disproportionate changes in LULC and LST are deemed to be the major contributors to UED. Findings from this study will serve as baseline for examining the influence of road network on regional urban growth and assist in sustainable road infrastructure planning. © 2020, © 2020 Informa UK Limited, trading as Taylor & Francis Group.

Geocarto International

Road network drives urban ecosystems - a longitudinal analysis of impact of roads in the central Himalaya

Lime-based mortar interlayer plays an important role in structural and architectural construction. Lime mortar undergoes repetitive changes in temperature when it is exposed to its service environment. Change in temperature has a significant effect on the thermal deformation of cement mortar and even affects directly the durability of century decade monuments and structure under extreme regions. This paper deals with thermal deformation of lime mortar, which is the prime constituent of cement and the oldest construction material by measuring its deformed geometrical configuration. In the first part, it is aimed to investigate the thermal deformation of mortar cube, its changes in length and mass of the specimens continuously measured during the heating and cooling cycles within the range of temperatures of −20 to 70 °C. The second part of this paper aims to investigate the pore formation and pore size distrubution in lime and lime mortar sample using optical microscopic images. Although a careful visual inspection can provide very good accuracy information, it has inherent limitations in assessing the structural integrity, and also, visual inspection can provide limited information to a damaged facility. In this paper, a detailed pore distribution analysis has done using digital image processing tool for better interpretation of thermal damages in lime mortar. The above-proposed tool can be used as aided tool for retrofitting and conservation of many architectural heritages. © Springer Nature Singapore Pte Ltd. 2020.

Thermal and Optical Investigation of Lime Mortar for Repetitive Thermal Loading

In this study, remote sensing-based algorithm, METRIC is used to estimate evapotranspiration (ET) over a mountainous watershed in the lesser Himalayas in Uttarakhand, India. ET estimates of METRIC are compared with the ET values determined by using FAO Penman-Monteith equation and crop coefficients. In its original form, METRIC underestimated the ET values considerably with mean absolute error (MAE) of 0.95 mm/day. A modification is incorporated in METRIC for better representation of the effect of rainfall on the ET process. The proposed modification estimates ET at the hot pixel using daily rainfall and meteorological data. Using the modification, the MAE is reduced to 0.44 mm/day and underestimation of ET is reduced from 20.9% to 8.4%. This study contributes to the better understanding of ET in the lesser Himalayas of Uttarakhand. It also underlines the importance of accurate assignment of ET to the hot pixel for accurate estimation of ET using METRIC.