Bank Protection Research Articles

Time-Domain Protection and Fault Location of Wye-Connected Shunt Capacitor Banks Using Superimposed Current and Differential Voltage

This paper presents protection and fault location of wye-connected shunt capacitor banks used in medium or high voltage applications. The proposed method is sensitive to single element failure obtained by using voltage adaptive instantaneous superimposed current in each phase. The change in equivalent reactance computed using time-domain signals is used to find the number of failed capacitor element and types of fault. The location of the faulted capacitor is identified using sign of the voltage difference of the lower and upper halves of the shunt capacitor bank. The performance of the proposed method is tested for various cases including identical faults, simultaneous faults, system voltage unbalance in both single and double wye-connected shunt capacitor banks. The method is also validated using field data collected from a 400 kV SCB for an internal fault. The proposed technique is compared with available methods and found accurate.

Enhancing transverse mixing by using triangular vane in the straight channel

The transport of pollutants in the large rivers especially in the lowest downstream reach of a river, in which the velocity and the intensity of flow turbulent become very low, is performed to a great extent by dispersion. Any measure to enhance the level of turbulence in the flow field will increase the mixing of pollutants. The main goal of the present study is to investigate how the transverse mixing is increased by using a triangular vane (TV). TV is a hydraulic structure used for bank protection and habitat restoration and is suitable for fish and other aquatic organisms. Experiments were carried out in a flume of 10m long and 0.8m wide. Two different conditions of with and no vane were tested under four different flow conditions. A salt solution was used as a tracer. An electronic concentration measuring equipment consisted of conductivity probes was used which can measure the concentration at 49 nodes in four cross-sections downstream simultaneously. The three-dimensional velocity components were also measured by using the electromagnetic velocity meter and the characteristics of three-dimensional flow patterns including turbulent kinetic energy (TKE) and the vertical distribution of the transverse velocity were analyzed. The result showed that the TV by deviating the velocity vectors to the transverse direction, by developing the secondary flows and by displacing the position of the rotating cells in different transverse sections, causes the transverse mixing to increase 3.2 times and to reduce the complete mixing length by as much as 76% compare to the case of no vane. The average values of the TKE found to be increased by as much as 3 times. Finally, a new dimensionless parameter has been proposed to correlate dimensionless transverse mixing to the flow parameters.

Identifying causes and management of river bank erosion in Majuli Island, India

River bank erosion is not only a major concern for those living on the bank, but it also causes huge economic losses to the habitants. Through case studies, it is noted that geogrid application is one of the most accepted and adoptable technique for the protection of slopes and the same is proposed for the protection of river bank of Majuli Island. Finite element-based numerical tool PLAXIS 2D is used for the numerical analysis of proposed river bank protection work to assess its stability as well as deformation pattern. To address the issue of uncertainty in input geotechnical parameters, concept of response surface methodology in combination with numerical analysis and first-order reliability method approach is used for the probabilistic analysis or assessing the performance of the proposed bank protection work in terms of an index, popularly known as reliability index “β”. The proposed methodology saves computational time and effort and useful for preliminary investigations when compared with computationally demanding approach like Monte Carlo Simulations. Through finite element-based numerical tools, it is established that the proposed deign for the protection work using geogrid will help in improving the stability of the slope and facing using shotcrete will help protect the bank for further erosion. Issues of uncertainty in the geotechnical parameters are presented, and it is emphasized that probabilistic approach is vital in assessing the stability in probabilistic framework as it treats uncertainty in mathematical framework and bring rationality in decision making.

An experimental study on the secondary flows and bed shear stress at a 90-degree mild bend with and without triangular vanes

River outer bank erosion and associated inner bank sedimentation cause river morphological and environmental changes. Triangular vanes are eco-friendly structures used for protection of river bank from erosion and morphological changes, fish passage improvement, and also fish habitat enhancement. In the present study, the 3D velocity components at a mild 90-degree channel bend were measured via an electromagnetic velocity meter with and without installed triangular vane. These tests were conducted at a Froude number of Fr = 0.214. The analysis of data showed that the triangular vane decreased the bed shear stress near the outer bank at the upstream and downstream sections of the vane for a distance of about 11 times the effective length of the vane. The maximum reduction at the upstream and downstream of the structure was calculated to be 67% and 80%, respectively. The strength of the vane-induced secondary flow was greater than that of the bend-induced secondary flow. At the position of 0.8L in the structure's downstream, the strength of the vane-induced secondary flow was maximum, after which started reducing and reached the strength of the bend-induced secondary flow at the position of 7L in the structure's downstream.

Bank Protection Structures along the Brahmaputra-Jamuna River, a Study of Flow Slides

The planform of the Brahmaputra-Jamuna River followed its natural path in Bangladesh until the construction of bank protection works started to save Sirajganj from bank erosion since the 1930s. Several so-called hardpoints such as groynes and revetments were constructed in the period 1980–2015 and the Jamuna Multipurpose Bridge was opened in 1998. The Brahmaputra Right Embankment and other projects had saved the western flood plain from inundation during monsoon floods. These river training works experienced severe damage by geotechnical failures, mostly flow slides. A flow slide is an underwater slope failure because of liquefaction or a breaching process in the subsoil or a combination of both. The design of most of these training works did not consider the risk of damage by flow slides. All descriptions of the observed damages show that scour phenomena in the channel close to a river training work are a cause of flow slides, besides pore water outflow. The research question was: how can the design of river training works be improved to reduce the risk of damage by flow slides? The main part of the investigation was focussed on reducing local scour holes near river training works. The most promising results are river training works with gentle bank slopes, permeable groynes, bed protections in dredged trenches with gentle side slopes, and methods to increase locally the bearing capacity of the subsoil. It is recommended to increase the knowledge of the failure mechanisms in the Brahmaputra-Jamuna River by improved monitoring in the field, the setup of a database with descriptions of all observed flow slides and the circumstances in which they occur. In addition to these recommendations, a field test facility is proposed to verify the knowledge of the failure mechanisms in that river. These activities will optimise the design of new river training structures with a very low risk of damages by flow slides and geotechnical instabilities and they will contribute to an improvement of the current design guidelines for river training structures.

Large eddy simulation of the turbulent flow field around a submerged pile within a scour hole under current condition

ABSTRACT Coastal finite structures, bridge piers, and bank protection structures may become submerged during storm surges. In the present study, a turbulent flow field around a submerged pile within a scour hole is numerically simulated considering a very fine mesh in the order of 50 million cells distributed within a relatively small computational domain. Necklace vortices, including two horseshoe vortices (HVs) and a junction vortex (JV), are detected upstream from the cylinder. In many snapshots, the tails of the HVs stretch in the flow direction, while their size and length change considerably over time. Downstream of the cylinder, the influence of the trailing vortex from the cylinder roof is mainly limited to a zone near the cylinder top, whereas the effect of the separated shear layers (SSLs) from the cylinder sides is dominant within a larger region. The strength of vorticity associated with the trailing vortex is mainly notable within the “very near wake” area, where the strength of the upward velocity component of the wake vortices generated from the cylinder sides mitigates. This paper describes the distribution and origin of streaks and rollers on the scoured bed, i.e. the main cause of sediment transported downstream of the cylinder.

Biodynamic timber sheet pile walls: vegetation retaining structure

Timber sheet pile walls are widely used for the protection of stream banks in different parts of the world. However, there is a tendency to create more sustainable types of stream banks not only because exploitable wood is more difficult to obtain, but also because of disturbance to the natural habitat of plants and animals due to hard embankments. In the Netherlands alone, about 2500 km of engineered timber sheet pile wall embankments exist, primarily made with tropical hardwood, besides an even much larger amount of ‘non-engineered’ small-size timber-based embankments. As an alternative, the authors propose to use a mixed timber sheet pile-vegetation system, where locally available timber can be applied in combination with natural vegetation. Unlike the usual bioengineering scheme, vegetation is not seen as an element, which could replace the timber sheet piles. Instead, a new perspective is tested, where the vegetation is included as a ‘structural’ element which can even counteract the consequences of time-dependent biological degradation of the timber sheet pile. By doing so, both long-term durability as well as reliability of the stream bank is improved. A comprehensive design strategy was developed based on well-established sub-models from the literature on plant growth, root reinforcement as well as timber damage accumulation. The timber sheet pile wall-vegetation system is illustrated in an example case study. Preliminary analysis including only the mechanical reinforcement of vegetation shows that there is a decrease in moment and shear acting on the timber sheet pile with growth of the vegetation. Consequently, the damage accumulation due to load duration effects on the timber decreases and the service life of the system increases. Thus, using vegetation in combination with highly degradable timber could possibly negate the need for using hardwood timber, or more generally, save resources that are currently used for these structures.

Man's impact on the transformation of channel patterns (the Skawa River, southern Poland)

AbstractThe research objective was to answer the question, how and why have the patterns of the channels of the lower course of the Skawa River changed over the past 200 years? This problem is important in the context of contemporary waterway construction plans in Poland. Overall, this study shows the effects of natural restoration in the event of the destruction of bank protections. The Skawa River is a mountain tributary of the Vistula River (southern Poland). In the first step, the channels were classified in the period from the 19th to the 21st centuries. In the second step, it was checked how channelization, water damming, gravel mining, embankment construction, changes in the forest area and channel incision, determined the change of the channel patterns. There were four periods in the functioning of the Skawa riverbed. In the first period (before 1901), the reaches of a natural riverbed were sinuous, braiding, or anabranching. In the second period (1901–1943), the riverbed was completely channelized. In the third period (1943–2003), the riverbed had artificial, braiding, and sinuous reaches. In the fourth period (after 2003), the riverbed had high energy anabranching and sinuous reaches. This study shows that man led to the transformation of the Skawa River channel due to the building of the network of navigable canals and rivers. This study shows how various factors can determine changes in the channel pattern, and that the destruction of bank protections enables natural restoration and forming the braided or anabranching channel pattern.

What Is a Debris Flood?

AbstractDebris floods have been defined descriptively as mineral and organic sediment‐rich floods, occurring in a steep channel and potentially destabilizing the streambed and banks. While this definition allows one to visualize the process, it does not inform on the mechanics, nor does it recognize different types. We propose to define debris floods as “floods during which the entire bed, possibly barring the very largest clasts, becomes mobile for at least a few minutes and over a length scale of at least 10 times the channel width.” We define the onset of a debris flood by the exceedance of a critical shear stress threshold required to mobilize at least the D84 of bed material. A threefold classification is proposed in which the first type is triggered by the shear stress exceedance. The second is initiated by transition from a debris flow either in the channel or by oblique impact of a debris‐flow‐prone tributary. In this context we highlight the importance of effective fluid density. The third type is associated with outbreak floods from artificial or natural dams. A further subdivision of debris floods is made by using the ratio of the actual shear stress to the critical shear stress, with higher values indicating damaging and finally catastrophic debris floods in which even preexisting channel bank and bed protection is mobilized. This contribution aims to provide a more succinct mechanistic definition of debris floods that can be implemented in hazard and risk assessments for steep streams and rivers.

Restoring a glacier‐fed river: Past and present morphodynamics of a degraded channel in the Italian Alps

AbstractThe present study explores the evolutionary trajectory of the glacier‐fed Mareit River (South Tyrol, Italian Alps), where a large restoration programme was implemented in 2008–2009. River corridor changes before and after the restoration works were assessed using historical maps, recent field observations, topographic surveys and topographic differencing. Trends of anthropic (forest cover, channel works, gravel mining) and natural (glacial cover, precipitation, flow regime) factors controlling channel morphology – at both catchment and reach scales – were reconstructed. From the mid‐19th century, the evolutionary trajectory of the Mareit River followed a degradational trend, characterized by channel narrowing, bed incision and planform simplification. Direct, in‐channel human alterations – mainly in the form of bank protections (in the late 19th century), gravel mining (mostly in the 1970s) and grade‐control works (since the 1980s) – dominated the historical adjustments before the restoration. In 2008–2009, a segment of the Mareit was restored by widening the channel, partly removing the check‐dams and shaping a braided pattern within a laterally constrained corridor. Post‐work monitoring shows that the restoration improved both the morphological quality and the geomorphic diversity. At present, the channel is subject to narrowing and slight bed level incision, with islands and floodplains progressively expanding at the expenses of the active channel. This trend is likely to continue in the next decades based on the expected future flow regime, and indeed the Mareit River seems to be attaining a ‘miniaturized’ version of the anabranching pattern of the mid‐19th century. Overall, this restoration approach and the associated evolutionary trajectory is considered positive, because it leads to a complex mosaic of geomorphic units, dynamically self‐adjusting to the time‐varying driving variables. The formation of a morphodynamically active corridor, while keeping artificially non‐erodible boundaries, represents an optimal strategy to integrate ecological improvements with flood risk mitigation in the densely populated Alpine valleys. © 2020 John Wiley & Sons, Ltd.

Akibat Hukum Pencairan Kredit Yang Didasarkan Pada Covernote Notaris

Tujuan penelitian ini ialah untuk mengkaji dan menganalisis akibat hukum pencairan kredit yang didasarkan pada covernote notaris. Tipe penelitian yang digunakan dalam penelitian ini ialah penelitian yuridis normatif dengan menggunakan pendekatan undang-undang, pendekatan konseptual, dan pendekatan kasus. Hasil dari penelitian Covernote yang dibuat atas dasar kesepakatan Notaris dan Bank dalam pencairan kredit adalah sah, namun hanya berkedudukan sebagai surat keterangan dari notaris dan tidak memiliki kekuatan hukum karena tidak ada kewenangan Notaris dalam pembuatan suatu Covernote. Akibat hukum pencairan kredit yang didasarkan pada covernote Notaris adalah apabila tidak dapat diselesaikan pengurusan hak tanggungan sesuai dengan covernote yang dibuat oleh Notaris, maka berakibat objek jaminan dalam perjanjian hak tanggungan tidak dapat dieksekusi langsung atau perjanjian hak tanggungan batal demi hukum sedangkan perjanjian kreditnya belum berakhir. Covernote Notaris tidak memiliki kekuatan hukum untuk memberikan perlindungan hukum bagi bank selaku kreditur dalam perjanjian kredit apabila terjadi wanprestasi pada saat proses pembebanan hak jaminan. Notaris dapat dimintakan pertanggungjawaban atas kesalahannya jika dalam penerbitan covernote tersebut terdapat unsur yang memuat keterangan yang tidak benar terhadap isi covernote tersebut.
 Kata Kunci: Covernote, Notaris, Perbankan

Análisis hidro-sedimentológico 2d del comportamiento de un campo de espigones para la protección de márgenes en un río meandriforme

ABSTRACT Alluvial rivers show a highly dynamic morphological patterns, which cause problems in the operation and maintenance of infrastructure located in their environment. In these cases, it is necessary to design structures to control bank morphodynamic processes. This article describes the hydro-sedimentology of the meandering channel called río del Valle (Argentina), for which bank protection was implemented on its outer bank. This study zone was selected for the cutting of an embankment located on the outer bank of the channel due to the excessive lateral migration of the meander. Flow structure and bed morphology patterns are analyzed and discussed using the results of the application of the TELEMAC 2D model coupled to the Sisyphe morphological module. These results allow us to identify vector patterns of velocity and streamlines in the groyne field, showing the development of a recirculation flow between groynes, as well as the influence in the displacement of the core of maximum velocity towards the center of the channel along the bend apex. The bed evolution shows the vertical regrowth of the bed in the groyne field and the reduction of the point bar in the bend entrance.

The Act Protection for Islamic Banks in Financing Land and Rubber Plantation Ownership

Islamic banks in channeling funds to the public with two types, namely financing with the profit sharing system and financing with the sale and purchase system with deferred payment. Revenue sharing system is a system that includes procedures for the distribution of results of operations between the fund provider and the fund manager. The system of buying and selling with deferred payment is a system with profit margins, namely by implementing a system of buying and selling at a bank as a seller or by appointing a customer to be used as a bank agent to make purchases of goods and then selling the goods to customers at the agreed base price and profit. In practice, financing through Islamic banks does not rule out the possibility of problems, such as defaults such as the case in the Muara Enim Religious Court.

Avaliação e Proposta de Novas Obras de Engenharia Natural para Estabilização de Taludes Fluviais do Rio Taquari no Município de Estrela, RS

O Parque da Lagoa, localizado no baixo curso do Rio Taquari, tem sido um sítio experimental para aplicação de modelos biotécnicos, que visam estabilizar e revegetar taludes fluviais susceptíveis aos processos erosivos. O presente trabalho busca avaliar atributos geotécnicos, ecológicos, econômicos e estéticos de técnicas de engenharia natural implantadas na área do parque no ano de 2010. A partir do diagnóstico destas intervenções biotécnicas, é proposto um projeto de revegetação e estabilização de taludes fluviais com uso das técnicas de bioengenharia, visando mitigar a erosão e ausência de vegetação ciliar que coloca em risco o rompimento da Lagoa Maria Dresch. No decorrer dos anos os modelos biotécnicos aplicados na área do parque adquiriram maturidade ao estabelecer uma vegetação, garantindo estabilidade e proteção às margens do rio. A proposta técnica sugere o uso do material dragado do canal de navegação do rio para remodelagem dos taludes fluviais e a aplicação das técnicas de enrocamento, esteira viva e banqueta vegetada, por serem soluções viáveis com baixo custo e menor impacto ambiental valorizando fatores ecológicos e paisagísticos. A engenharia natural se apresenta como uma alternativa ambientalmente sustentável e os resultados comprovaram sua eficiência como facilitadora para desenvolvimento da vegetação ciliar, e como ferramenta para correção e diminuição dos processos erosivos ao longo dos cursos d’água.

Evaluating stream bank instability and toe erosion using BSTEM model for the Amu river

Loss of land, disputes on sharing costs, and benefits of transboundary waterways are points of debate between neighboring countries. Unfortunately, weak, undeveloped countries always suffer more than their stronger neighbors. Due to economic, political, and institutional problems, Afghanistan is one country that faces challenges to develop the potential of its water resources. Each year, Amu River flooding causes great losses of land due to massive bank degradations and erosions for up to several kilometers. Currently little progress has been made to study, research, or manage the bank erosions of the Amu River. In the absence of field data, the Bank Stability and Toe Erosion Model (BSTEM) may be used to analyze stream bank stability and toe erosion. This study was conducted to describe the Amu River stream bank using the BSTEM model for a restoration process. A field survey was conducted from February 3, 2019, to February 23, 2019; soil type, layer thickness, water table depth, and stream bank profile are entered into the BSTEM model with two different flow depths according to insights from villagers and well-diggers. Mass failure and toe erosion are two dominant mechanisms of Amu River bank failure, and the effectiveness of vegetation on bank protection is observed.

Bank risk management in the conditions of financial system instability

Purpose of research is to influence prompt decision-making on the financial market in case of risk management of the bank. The banking sector is usually undergoing a serious reform phase. Investigating the bank's risk management basics using modern approaches to risk assessment and management in banking. The bank's risk leads to the loss of credit institutions and deterioration of liquidity, due to adverse events occurring, depending on internal and external factors. The article discusses the organization of the bank risk management system, methods of risk management, quantitative and qualitative risk assessment. Banks use various methods to reduce their risk. The main types of risks, risk management system, ways of managing bank risks and ways to reduce them were considered. Quality of the bank's management, especially the risk management process, are the key factors that ensure stability and security of banks and the banking system as a whole. Common methods of scientific research have been developed. It is necessary to pay special attention to the risks of banks on the financial market. The deterioration of the situation in the financial market was associated with problems accumulated over many years, and some problems were solved, which in turn led to risks. The structure of the bank's risk management mechanism is presented, the characteristics of its elements are identified and the key objectives of the management mechanism are identified. In the study, all banks in the financial market were analyzed using the models in Gretl, with the major risk factors being analyzed. The mechanism of risk protection of banks consists of current methods of risk management and methods of its reduction. The roles, responsibilities and powers of regulatory bodies in the creation of an effective system of legal norms regulating the peculiarities of the risks taken by the bank are risk management as an element of the internal control system of banks. In the conditions of instability of the modern economy, the banking market can not be risky. The risk is in any bank activity, but it can be at different levels. In addition, the current risk management is to monitor important indicators and timely adopt operative decisions on banking transactions.

Analysis of Hydraulic Failure Mechanism of River Bank Protection and Reinforcement Treatment Practice

Based on the reinforcement engineering of the revetment retaining walls at the lower reaches of a reservoir, this study analyzes the fracturing mechanism and proposed technically-advanced, economical and feasible reinforcement measures, which provide important reference for similar engineering work.

Application of the Asymptotic Extreme Value Probability Theory to Forecasting the Risk of High Floods in the Lower Amur

A characteristic feature of the Amur River is the frequent catastrophic floods, which cause considerable damage to the population and hamper economic activity. Statistical analysis of the maximal annual water levels in the Amur at Khabarovksk gage over the observation period since 1896 to 2016 gave analytical expressions for probability distribution functions of the general populations of water levels over the entire observation period, as well as over periods of originally weak (1896–1960) and current (1961–2016) intense economic development of the Amur basin. It was shown that the risk of high floods had decreased recently by half, while the average intervals of their recurrence had doubled compared with the previous period. The intense economic activity in the Amur basin in the recent decades was shown to have caused a decrease in the most likely water levels by 0.5 m. Overall, the hazard of high floods in the valley of the lower reaches of the Amur have decreased, however, accompanied by an increase in the amplitude of water level marks and its extreme values for individual years, as was manifested in the catastrophic 2013 flood. Calculations show that the average recurrence period of this outstanding flood is 144 years and its probability is 0.7%. The obtained data can be used in the development of a system of bank protection and channel-forming measures in the lower reaches of the Amur in the assessment of the anthropogenic impact on changes in water regime and water and floodplain ecosystems of the river.

Geoengineering Protection of Territories Violated by Objects of Accumulated Environmental Damage

An approach is presented that allows to choose the facilities of geoengineering protection of accumulated environmental damage. This approach is based on taking into account the peculiarities of the hydrogeological, hydrological, geomorphological situation of territories where the objects are located, as well as their ranking depending on the environmental burden. A practical example of arrangement of a large storage of hazardous waste of the chemical industry is considered. Such protection with a perimeter waterproofing curtains combines the anti-filtration functions, bank protection and strengthening the bearing capacity of soils. For the first time, a curtain based on soil-cement piles was used as alternative to the well-known sheet pile technologies to protect the geological environment and watercourse during lateral filtration of contaminants of slurry body.

ABOUT THE LEGAL RESPONSIBILITY OF THE CENTRAL BANK IN MONETARY LAW

The subject of the analysis in this paper is to identify and evaluate the concept of central bank legal responsibility in the contemporary monetary law. In this regard, the research focuses on issues related to the need of clarifying and defining the nature, type and extent of central bank liability and compensation mechanisms for damage that may be caused to third parties in the implementation of the transferred lex monetae in practice. The first part of the paper focuses on the axiological and dogmatic analyses of the legal framework of the central bank, which is governed by the national monetary legislation sui generis, and the interpretation of different legislative solutions in the practice of comparative monetary law in the area of responsibility and legal protection of the central bank. The subject of special interest of the authors is the monetary-legal analysis of the relevant provisions of the Law on the National Bank of Serbia, since in their opinion, a clear determination of the responsibility of the supreme monetary institution is a precondition for its credibility, not only in national but also in the international monetary order, and a conditio sine qua non of creating a reputable and consistent national monetary jurisdiction.