Faculty Publications
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Item Integrated coastal zone management plan and coastal zone information system for Mangalore Coast, West Coast of India(2006) Dwarakish, G.S.; Shetty, D.; Rajarama; Pai, J.; Natesan, U.In the present study, Integrated Coastal Zone Management Plan (ICZMP) has been developed for Mangalore Coast in Karnataka, along the West Coast of India, by analyzing the remotely sensed data and conventional data. The various data products used in the present study includes, IRS-1C LISS-III+PAN and IRS-P6 LISS IV remotely sensed data, Naval Hydrographic Chart and Survey of India (SOI) toposheets. Different thematic maps prepared in the present study includes, land use/ land cover map, bathymetry map, shoreline configuration map, transportation and drainage network maps, GPS survey map, CRZ map, contour map, DEM, inundation map and coastal erosion vulnerability map. The results of the present study are encouraging. Some of the specific conclusions of the study are; eight coastal vulnerability sites have been identified, significant increase in the built-up area and decrease in the agricultural land, no large scale erosion or deposition in the vicinity of coastal structures such as seawalls, breakwaters and entrance channel of New Mangalore Port Trust and the beaches along the Mangalore Coast are maintaining dynamic equilibrium. To get the online information about all these, Coastal Zone Information System (CZIS) has been developed through V. B. 6. 0. using results of various data analyses.Item Physical Model Tests for Newly Developed Breakwater Foundation Subjected to Earthquake and Tsunami(Springer Science and Business Media Deutschland GmbH, 2021) Chaudhary, B.; Hazarika, H.; Murakami, A.; Fujisawa, K.Many breakwaters damaged due to earthquake and tsunami in the past. For example, several breakwaters collapsed by the 2011 off the Pacific Coast of Tohoku Earthquake and subsequent tsunami. It was found that these breakwaters damaged mainly due to the failure of their foundations. Therefore, countermeasures are urgently needed to be developed for breakwater foundation in order to make the breakwater safe against earthquake and tsunami. Recently, new countermeasures were developed by the authors for breakwater foundation in order to make it resilient against an earthquake and tsunami. This paper deals with evaluation of effectiveness of the developed foundation model by conducting shaking table tests and tsunami overflow tests. As reinforcing countermeasures, steel sheet piles and gabions are provided in the breakwater foundation. To see the performance of the developed model, comparisons are made between the developed foundation model and conventional foundation. Through the tests, it was found that the reinforced foundation performed well in reducing damage of the breakwater caused by the earthquake and tsunami. © 2021, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.Item Tsunami Resilient Foundation for Breakwater: Centrifuge Model Tests(Springer Science and Business Media Deutschland GmbH, 2021) Chaudhary, B.; Hazarika, H.; Murakami, A.; Fujisawa, K.Many coastal protection structures collapsed due to the past earthquakes and tsunamis. For example, several breakwaters damaged during the 2011 Great East Japan Earthquake and Tsunami in Japan. Due to the failure of the breakwaters, the tsunami waves could not be blocked by the breakwaters. Thus, the tsunami entered in the coastal areas; and imposed deep devastation there. It was found that the breakwaters damaged mainly due to their foundation failures. In order to mitigate such damage of breakwater caused by earthquake and tsunami, new techniques were developed by the authors for breakwater foundation. In the technique, gabions and sheet piles are used in breakwater foundation. Effectiveness of the developed foundations model of breakwater were evaluated by conducting centrifuge model tests. It was observed that the developed models could mitigate damage, and make the breakwater resilient against earthquake and tsunami-induced damage. © 2021, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.Item Review of Literature on Design of Rubble Mound Breakwaters(Springer Science and Business Media Deutschland GmbH, 2023) Akarsh, P.K.; Chaudhary, B.Breakwaters are offshore structures constructed to protect the coastal and port structures from uncertain and extreme wave conditions. It creates tranquility in and around the harbor side for smooth transactions of ships. Depending upon the availability of rocks, depth of water, geotechnical nature of the sea bed, and its functional requirement, breakwaters are classified as rubble mound breakwaters, caisson type, and composite breakwaters. Rubble mound is a flexible, heterogeneous, trapezoidal structure consisting of quarried rocks in the core and artificial armor as a protection cover. Armor units at the outer layer absorb most of the energy and under-layers prevent transmission of the wave energy. The main advantage of the rubble mound is its failure is not immediate and can be repaired by adding the stones in the flushed-out part. More than 50% of breakwaters constructed around the world are of rubble mounds. Looking at its importance for coastal structures, this paper gives an overview of the basic aspects of rubble mound breakwaters, design considerations, and its failure conditions. The design of rubble mound breakwaters include hydraulic stability of it against wave actions, structural components design, and geotechnical considerations. The common modes of rubble mound failure are hydraulic damage, erosion of subsoil, slope failures, toe erosion, overtopping, liquefaction of subsoil, crest erosion, and leeside damage. The failure of rubble mound breakwater at Ergil fishery port, Turkey due to Kocaeli earthquake of 1999 has been explained to support this part. © 2023, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.Item Item Physical model studies on stability of concrete armoured breakwaters(2011) Rao, M.; Rao, S.; Shirlal, K.G.; Prashanth, J.; Balakrishna Rao, K.As the breakwater construction started moving in to deeper waters, the wave load on its armour increased resulting in usage of heavier armour units inviting environmental and logistical problems. With the advancement in the technology, concrete armour units have been extensively replacing the natural stones with benefits such as saving in the material and cost while reducing loads on the seabed and helping in construction of environment etc. Tandem breakwater and berm breakwater could be the alternative solutions for the above said case. This paper presents the two cases of physical model studies on the stability of concrete armoured structures, one with tandem breakwater and another on berm breakwater. Both the models are subjected to monochromatic waves with varying characteristics. From the study it was observed that in case of tandem breakwater the crest width of submerged reef and the distance between breakwater and reef are the defining parameter while in case of berm breakwater the height of the berm and its width are the characteristic factors in reducing the breakwater damage. © 2011 Taylor & Francis Group, LLC.Item Multiple Nonlinear Regression Analysis for the Stability of Non-overtopping Perforated Quarter Circle Breakwater(Editorial Board of Journal of Harbin Engineering, 2020) Shahulhameed, S.; Rao, S.; Hegde, A.V.Breakwaters have been built throughout the centuries for the coastal protection and the port development, but changes occurred in their layout and criteria used for the design. Quarter circle breakwater (QBW) is a new type evolved having advantages of both caisson type and perforated type breakwaters. The present study extracts the effect of change in the percentage of perforations on the stable conditions of seaside perforated QBW by using various physical models. The results were graphically analyzed using dimensionless parameters and it was concluded that there is a reduction in dimensionless stability parameter with an increase in steepness of the wave and change in water depth to the height of breakwater structure. Multiple non–linear regression analysis was done and the equation for the best fit curve with a higher regression coefficient was obtained by using Excel statistical software—XLSTAT. © 2020, Harbin Engineering University and Springer-Verlag GmbH Germany, part of Springer Nature.Item Shoreline Changes Around Three Estuarine Harbours on Kerala Coast in India(Seventh Sense Research Group, 2023) Paravath, K.; Thuvanismail, N.The shoreline, the land and water boundary is subjected to periodic changes due to different dynamic factors like, bathymetry, wave characteristics, currents, and coastal orientation. Coastline variation leads to erosion and accretion phenomena on the coast. In the present study, the coastal changes around three estuarine harbours along Kerala coast in India are analysed by using numerical method. The impact of harbour constructions on shoreline are assessed from this study. Mike 21 SW and LITPACK modules are used to predict the shoreline changes at these three estuarine harbour sites along Kerala coast. The analyses on coastline oscillations around three estuarine harbours show significant impact of harbour constructions on adjacent coast. © 2023 Seventh Sense Research Group®.