Browsing by Author "Lokeshwari, M."

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Effect of Water Content on Relative Flow Area and Hence Predicted Flow Values of Controlled Low Strength Materials
(American Society of Civil Engineers (ASCE), 2018) Raghavendra, T.; Udayashankar, B.C.; Lokeshwari, M.; Shelar, M.; Amaranath Reddy, N.
Urban cities are embracing new innovations in built-up spaces and thereby necessitating renovations or constructions for new buildings either by demolition of obsolete buildings or at new places to expand the city itself. In this regard natural stones are converted to aggregates and hence generate stone dust as a waste. Construction and demolition wastes include brickbats which are used as in-fills. Many attempts have been made to re-use these wastes but still the problem persists and large percentages of these wastes reach landfills. Controlled low strength materials (CLSM) are an obvious choice for use of these wastes in large quantities, required for sustainable city objectives. CLSM is a cementitious and self-flowing backfill material. Design of CLSM mixes involves iteration process mainly to satisfy the flow and strength requirements. Phenomenological models are an effective tool in the design of CLSM mixtures with a single trial. In this paper Class F fly ash was used as secondary cementitious material along with powdered brickbats, stone dust as fine aggregates in complete replacement to natural sand; to produce sustainable CLSM mixtures with varying Class F fly ash to cement ratios and water contents. Spread flow and marsh cone flow tests were conducted on fresh CLSM mixtures and compressive strength tests were carried out on hardened cylindrical specimens at 3, 7, 28, and 56 day age. Spread flow values were converted to relative flow area values. Phenomenological models (flow and strength) were generated using wide range of experimental data to predict flow and strength values. The water demand of quarry dust mixes was more compared to brickbats mixes and this resulted in lesser flow values and hence non-flow results. Incorporation of these non-flow values in the generation of flow prediction models resulted in poor prediction of flow results; however strength prediction was not influenced. Discarded brick bats and quarry dust are hence recommended for use as fine aggregates along with Class F fly ash as secondary cementitious material in CLSM to overcome urbanization challenge for sustainable development. Â© 2018 American Society of Civil Engineers.
Peak flood estimation along southern coast: Kerala, India
(2018) Lokeshwari, M.; Mendi, V.; Reddy, N.A.
India being an agricultural based country depends mainly on rain water and river for the purpose of irrigation and other domestic uses. Due to deforestation and urbanization, large area of unpaved surface is converted into paved surface, which prevents percolation of rainwater into ground. As a result, surface runoff and intern the chances of flood increases. Flood causes damage to hydraulic structures, agricultural land, properties and lives. On the other hand many states of India are facing water scarcity. So it is important to carry out flood forecasting to reduce uncertainties in hydrological predictions, which balances these two problems. Some of the catchments in India are ungauged as a result, surface runoff estimation will be inaccurate and also it is very difficult to understand catchment properties and hydrological response to rainfall. Suitable methods are desirable for hydrological evaluation of watershed in the absence of runoff-rainfall data. Remote Sensing and Geographic Information System with appropriate rainfall runoff models, provides ideal tool for estimation of direct runoff, peak discharge and hydrographs. This study focuses on estimation of peak flood discharge at coastal inlets, from river outlets along the southern coast of India in Kerala. Flood estimation methods recommended by Central Water Commission (CWC) India, in report 5a and 5b is considered as reference and Soil Conservation Service Method (SCS) used for peak flood estimation. � 2018 World Scientific Publishing Co. Pte. Ltd.
Peak flood estimation along southern coast: Kerala, India
(World Scientific, 2018) Lokeshwari, M.; Mendi, V.; Reddy, N.A.
India being an agricultural based country depends mainly on rain water and river for the purpose of irrigation and other domestic uses. Due to deforestation and urbanization, large area of unpaved surface is converted into paved surface, which prevents percolation of rainwater into ground. As a result, surface runoff and intern the chances of flood increases. Flood causes damage to hydraulic structures, agricultural land, properties and lives. On the other hand many states of India are facing water scarcity. So it is important to carry out flood forecasting to reduce uncertainties in hydrological predictions, which balances these two problems. Some of the catchments in India are ungauged as a result, surface runoff estimation will be inaccurate and also it is very difficult to understand catchment properties and hydrological response to rainfall. Suitable methods are desirable for hydrological evaluation of watershed in the absence of runoff-rainfall data. Remote Sensing and Geographic Information System with appropriate rainfall runoff models, provides ideal tool for estimation of direct runoff, peak discharge and hydrographs. This study focuses on estimation of peak flood discharge at coastal inlets, from river outlets along the southern coast of India in Kerala. Flood estimation methods recommended by Central Water Commission (CWC) India, in report 5a and 5b is considered as reference and Soil Conservation Service Method (SCS) used for peak flood estimation. Â© 2018 World Scientific Publishing Co. Pte. Ltd.
Urbanization Challenges in Emerging Economies
(American Society of Civil Engineers (ASCE) onlinejls@asce.org, 2017) Mendi, V.; Reddy, N.A.; Lokeshwari, M.; Raghavendra, T.; Seelam, J.K.
Tidal inlet is an opening along the coast which facilitates the exchange of water and nutrients. The energy extracted at the tidal inlet using tides is called tidal energy. Tidal energy is reliable and not depleting. Since the density of seawater is 800 times denser than air, the energy extraction is much favorable and reliable resource. Because of the above said advantages, tidal energy production has become an important energy source at global platform. The study area chosen is the Sri Lankan coast. The tidal condition along the Sri Lankan coast is semi diurnal. Identification of the locations for energy extraction is important as the width of the identified inlet at the coast plays an important role in energy extraction. Also, parameters like tidal range, basin area have to be taken into account in order to consider the inlet suitable for energy extraction. In this paper, tidal inlets will be identified along the Sri Lankan coast, the data will be collected for the parameters that are required to consider an inlet for energy extraction and the potential energy that can be extracted at the inlets will be assessed. Â© 2018 American Society of Civil Engineers.
Urbanization Challenges in Emerging Economies
(American Society of Civil Engineers (ASCE) onlinejls@asce.org, 2017) Amarnatha Reddy, N.; Mendi, V.; Raghavendra, T.; Lokeshwari, M.
The unit hydrograph (UH) concept needs observed rainfall-runoff data at the gauging site for hydrograph generation. But many catchments and watersheds in India are devoid of gauging stations and also it is not economically justifiable to collect the data and carry out detailed hydromorphological studies at every new site on a large scale. The paucity of such data sparked the idea of the synthetic unit hydrograph (SUH) concept. Most SUH procedures seek to establish relationships between parameters used to describe the UH and parameters used to describe the basin. In totality the available synthetic unit hydrograph methods/models have been classified into four groups as: traditional (or empirical), conceptual, probabilistic, and geomorphological. In the present study the probabilistic or probability distribution function (PDF) based methods/approaches are used to estimate the flood discharge at the ungauged basins in Varrar Basin at the coastal state of Kerala. The PDF based methods viz. Gray's method, Croley method, transmutation approach, and simplified gamma approach are used to develop UH at ungauged watersheds. The results of the total flood discharge at the ungauged basins are compared with volume of 1 cm direct runoff depth. Â© 2018 American Society of Civil Engineers.
Urbanization Challenges in Emerging Economies
(American Society of Civil Engineers (ASCE) onlinejls@asce.org, 2017) Lokeshwari, M.; Mendi, V.; Raghavendra, T.; Reddy, A.; Udayashankar, B.C.
Rapid urbanization, industrialization, and change of life style of people has increased the rate of solid waste generation by leaps and bounds in the developing countries. Municipal solid waste generation varies with place to place and the standard of living of the people residing in cities. Solid waste consists of organic matter, which undergoes degradation and produces foul smell, if not properly managed. Therefore management of the garbage had reached a very critical stage and now emphasis has been given to its collection, treatment, and final disposal. Generally in Indian cities, waste is collected and simply dumped outside the cities which are called as landfill sites. Any method of disposal other than composting will be uneconomical, required skilled person, and also pollute air, water, and soil. Large quantity of plant nutrients gets wasted in other methods of disposal. Composting is not a method of waste disposal but it is a method of recycling the waste. Municipal solid waste is one of the potential organic nutrient residues, which upon recycling leads to a valuable compost, which is vital for growth and development of plants. Sewage sludge is rich in micro-organisms, organic content, as well as nutrient elements. So in this study co-composting of municipal waste with sewage sludge has been taken up to conserve nutrients. In the present work studies were conducted on municipal solid waste, mixed with sewage sludge in different proportion, to check the technical viability of the integrated system of composting. Addition of sewage sludge to waste for composting not only increases decomposition rate and fertility value, it also solve the problem of sludge disposal from treatment plant. It will save the cost of sludge treatment. Municipal waste compost can be regarded as being valuable in soil management practices because of their organic matter content. Â© 2018 American Society of Civil Engineers.