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1

Problems of environmental interference in emergency repairs of railway sections - a case study

Sobkowiak Tomasz

Structure and Environment

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2025

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Vol. 17, no. 1

40--48

EN

This article presents the history of identifying the causes of emergency threats and the repair of a section of the railway line within the Wolin National Park. The author focuses on issues related to the legal aspects of environmental protection in a specially protected area that arose during the design and execution of repair works on the railway infrastructure. Numerous meetings between the Management of the Railway Line Department in Szczecin and the Management of the Wolin National Park, with both sides fully understanding the essence of technical and environmental problems of the project, led to a consensus. The scope and method of repair were established, allowing the minimization of the negative impact of the investment process on the park’s natural and environmental values while ensuring the safety of train traffic. Despite the typical and straightforward nature of the repair task, due to environmental protection constraints, non-standard construction problems were encountered, which consequently increased costs and extended the construction time.

PL

W artykule przedstawiono historię ustalenia przyczyn zagrożenia awaryjnego i naprawy odcinka linii kolejowej w obrębie Wolińskiego Parku Narodowego. Autor skoncentrował się na problemach związanych z prawnymi aspektami ochrony środowiska przyrodniczego na terenie obszaru szczególnie chronionego, które wystąpiły w trakcie projektowania, jak i wykonywania budowanych robót naprawczych kolejowej infrastruktury komunikacyjnej. Liczne spotkania pomiędzy Dyrekcją Zakładu Linii Kolejowych w Szczecinie a Dyrekcją Wolińskiego Parku Narodowego, przy pełnym zrozumieniu przez obie strony istoty problemów technicznych i środowiskowych przedsięwzięcia, doprowadziły do uzyskania konsensusu. Ustalono zakres i sposób naprawy, który pozwolił na zminimalizowanie negatywnego oddziaływania procesu inwestycyjnego na walory przyrodnicze i środowiskowe parku przy zapewnieniu bezpieczeństwa ruchu pociągów. Mimo typowego i prostego w realizacji zadania przy wykonaniu naprawy, ze względu na obostrzenia wynikające z ochrony środowiska przyrodniczego, natrafiono na niestandardowe problemy budowlane. W konsekwencji wpłynęło to na wzrost kosztów oraz wydłużenie czasu realizacji robót budowlanych.

2

Geotextile materials based on sheep wool in erosion control

Grzybowska-Pietras Joanna, Antonik-Popiołek Patrycja, Borecka Dominika

Materiały Budowlane

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2025

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nr 6

135--142

EN

With the increasing demands of a circular economy, the use of natural waste materials is important. This paper discusses the use of Kemafil ropes of biodegradable sheep’s wool geotextiles, arranged in a grid as slope erosion protection. The research showed that they serve functions of drainage and retention, storing water in the surface layer of the soil.

PL

W obliczu rosnących wymagań dotyczących gospodarki o obiegu zamkniętym ważne jest wykorzystanie naturalnych materiałów odpadowych. W artykule omówiono zastosowanie sznurów Kemafil z biodegradowalnych geowłóknin z wełny owczej, ułożonych w kratownicę stanowiącą zabezpieczenie przeciwerozyjne skarp. Badania wykazały, że pełnią one funkcje drenażową i retencyjną, magazynując wodę w warstwie przypowierzchniowej gruntu.

3

Assessment of the Morphological Dynamics of the Danube Riverbanks in the Ceatal Izmail Bifurcation Area

Iordache Gabriel, Dutu Laura, Catianis Irina, Dutu Florin, Dragos Andrei Gabriel

Inżynieria Mineralna

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2025

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Vol. 3, no. 2

1-7

EN

The genetic processes of a riverbed significantly influence its dynamics, shaped by various active factors, such as liquid and solid flow, and passive factors, including geological characteristics, geomorphometric features, and the granulometry of the riverbed. In a river bifurcation, the distribution of water flow and sediments downstream between the branches is uneven, leading to alterations in the riverbed and banks. Understanding the dynamics of the riverbed in confluence areas is crucial for managing water resources, assessing flood risk, predicting the long-term morphological evolution of the branches, and ensuring the success of river regulation projects. This study aims to evaluate the dynamics of the Danube banks from 2003 to 2020 in the confluence area at Ceatal Izmail, located at the entrance to the Danube Delta at Mm 43 (Km 80). A diachronic analysis of satellite images was performed to illustrate the riverbank dynamics in the Ceatal Izmail bifurcation, providing highly effective and yielding valuable results. For this study, we utilized Landsat 8 OLI/TIRS satellite images and images from Google Earth from the studied period and topographic surveys carried out in 2020 using a Trimble R4 RTK GPS. As a result of the satellite images analysis of and topographic measurements of the Danube banks, we created a map showing the changes in the banks of the Ceatal Izmail bifurcation between 2003 and 2020. Significant changes were observed during this period, attributed to erosion or sediment accumulation. Some sectors exhibited relative stability, remaining unchanged throughout the analyzed period. The area most impacted by erosion is located on the right bank of the Danube, between Mm 43.8 and Mm 43, where the erosion of the riverbank varies between 15 and 70 meters. This sector was monitored in 2021, 2022, and 2023 through topographic surveys of 20 trees arranged in two alignments at the edge of the Danube riverbank. We also calculated the erosion rate. After processing the collected data, we found significant changes in the distance between the first row of trees and the edge of the right Danube bank. Five trees marked in the first alignment fell into the water due to bank collapse. As a result of the erosion affecting the banks, the area of land lost between 2003 and 2020 totaled approximately 3.8 hectares. The most significant sectors with sediment accumulation are located on the right bank of the Chilia branch and on the left bank of the Danube between Mm 43.8 and Mm 43, where the total area of land gained through sedimentation at the bifurcation banks was 10.7 hectares. In this study, we calculated the erosion and deposition rates by considering three cross-sections on each bifurcation branch. The rates of erosion and sedimentation varied, ranging from -1.04 m to +2.01 m for sections on the Danube, from -0.47 m/year to +4.15 m/year for sections on the Chilia branch, and from -1.03 m/year to +1.07 m/year for sections on the Tulcea branch.

4

Prediction of degradation in 90° elbow joints of ba35 brass used in potable water pipes through computational fluid dynamics (CFD) simulation

Bennis H. T., Zniker H., El Kouifat M. K., Bennajah M., Ouaki B.

International Journal of Applied Mechanics and Engineering

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2025

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Vol. 30, no. 2

46--61

EN

Failure of 90° elbows in water pipes due to corrosion is a critical issue in water supply and distribution systems. Therefore, understanding the behavior of pipelines under corrosion is essential to increase their durability. This original study aims to specifically analyze the failure of 90° elbows due to the erosion-corrosion phenomenon. The behavior of water flow, in terms of velocity profile, pressure gradient, and turbulence zones at these elbows, is numerically simulated using the computational fluid dynamics (CFD) method. The simulations, performed with FLUENT software, identify the areas most susceptible to erosion and corrosion, thus contributing to a better understanding of processes such as stress corrosion cracking and cavitation. This work also highlights the importance of designing elbows with suitable characteristics and adopting adequate maintenance practices to prevent failures. These results can serve as a basis for future experimental validations and for the design of more robust pipeline systems.

5

Prioritizing sub-watersheds for soil management and conservation in the Wadi Ouergha watershed, Northern Morocco

Naoui Basma, Akka Latifa Ben, Titafi Asmae, Nassri Kawtar, El Idrissi Soukaina, Baghdad Bouamar, Chakiri Said

Ecological Engineering & Environmental Technology

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2025

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Vol. 26, iss. 1

235--256

EN

The Wadi Ouergha watershed faces significant challenges due to erosion, which directly impacts sedimentation rates and reduces the water storage capacity of the El Wahda dam, a crucial infrastructure for the region. This study aims to prioritize the sub-watersheds most vulnerable to erosion, which pose a direct threat to the dam’s efficiency. Through morphometric and hypsometric analysis, the research evaluates the geomorphological evolution, hydrological characteristics, and erosion risks within the sub-watersheds. The results indicate that sub-watersheds SW 6, SW 7, and SW 11 are the most at risk, with high drainage densities and advanced erosion stages, demanding immediate intervention. Sub-watersheds SW 2, SW 3, SW 4, SW 5 and SW 7 are identified as moderately vulnerable but still require erosion control measures to prevent long-term degradation. The findings underscore the need for targeted soil management and conservation efforts in these priority areas. This study introduces a novel integration of spatial analysis with statistical methods, incorporating weighted compound factors (WCF) and quartile analysis to prioritize sub-watersheds according to their vulnerability. This method enables a data-driven classification, establishing a structured framework for conservation priorities. Through combined numerical rankings and spatial mapping, decision-makers gain a clear visualization of high-risk areas, facilitating more targeted watershed management and optimized resource allocation.

6

Thermal impacts on the erosion of compacted bentonite under flow rate

Bülbül Süleyman, Sedighi Majid, Sevim Ozer

Archives of Civil and Mechanical Engineering

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2025

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Vol. 25, no. 1

art. no. e13, 2025

EN

Compacted bentonite is widely used as a filling and barrier material for underground storage of spent nuclear fuel waste due to its favorable properties. Over its design life, this compacted clay may be exposed to groundwater from the surrounding host rock. Depending on the modeling approaches and assumptions, the temperature to which the compacted bentonite will be exposed can vary. This paper presents the findings of laboratory investigations on the erosion of compacted bentonite at ambient temperature (26 °C) and elevated temperature (80 °C) temperatures. The compacted bentonite samples, with dry densities of 1.72 g/cm3 and 1.73 g/cm3 were subjected to erosion under a flow rate of 0.22 ml/min at 26 °C and 80 °C, respectively. The dynamic light scattering (DLS) method was employed to measure the size and quantity of the eroded particles. The amount of daily erosion and the size of the eroded particles were determined from effluent samples. The results indicate that the amount of eroded bentonite particles increased significantly with increasing temperature. Additionally, as temperature increased, the size of bentonite particles in the effluent decreased within a specific range. At 26 °C, particle sizes ranged from 59 to 6358 nm, whereas at 80 °C, the particle size distribution narrowed.

7

Błędy projektowe i wykonawcze płyty fundamentowej garażu podziemnego

Niedostatkiewicz Maciej, Majewski Tomasz

Przegląd Budowlany

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2024

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R. 95, nr 6

12--18

PL

W artykule przedstawiono opis uszkodzeń płyty fundamentowej garażu podziemnego, która została błędnie zaprojektowana, a następnie wykonana w sposób niezgodny z zasadami wiedzy technicznej. Bezpośrednio po zakończeniu realizacji płyty na jej powierzchni wystąpiły intensywne zarysowania, które miały charakter nieustabilizowany i ulegały dalszemu rozwojowi w czasie. Wykonana na płycie w ramach prac wykończeniowych posadzka również uległa zarysowaniu. W pracy przedstawiono zakres proponowanych prac naprawczych zarówno samej płyty fundamentowej, jak i uszkodzonej posadzki, tj. górnej powierzchni wykończonej zasypką utwardzoną powierzchniowo.

EN

The article presents a description of damage to the foundation slab of an underground garage, which was incorrectly designed and then constructed in a manner inconsistent with the principles of technical knowledge. Immediately after the completion of the foundation slab, intense scratches appeared on its surface, which were unstable and continued to develop over time. The floor made on the foundation slab as part of the finishing works was also scratched. The work presents proposals for the scope of repair work both on the foundation slab itself and on the damaged floor, i.e. the upper surface finished with surface-hardened backfill.

8

Development of thermal leak detection method and monitoring of seepage and internal erosion processes in earth dams, levees and dikes and their implementation in Poland

Radzicki Krzysztof, Stoliński Marek

Materiały Budowlane

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2024

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nr 12

55--77

EN

To reduce the costs of repairs and the risk of damming structures failures, methods for their investigations and monitoring are currently being intensively developed. The thermal method is globally recommended for studying intensive seepage, including the detection of leaks and internal erosion processes in earth damming structures such as earth dams, canal dikes, and levees. The article presents the key aspects of the development of this method and its implementation in Poland. It describes its principles and pilot applications on existing and newly constructed dams and levees in Poland, using thermal sensors for linear measurements, such as the MPointS multipoint sensor and fiber optic cables. The development of a thermo-hydraulic numerical modelling for the highly accurate determination of the geometry of individual zones and the hydraulic conductivity values within the cross-section of an existing earth dam, including the identification of erosion process zones, is presented.

PL

W celu ograniczenia kosztów remontów oraz ryzyka katastrof budowli piętrzących intensywnie rozwijane są obecnie metody ich badań oraz monitoringu. Metoda termiczna jest rekomendowana na świecie do badania nasilonej filtracji, w tym detekcji przecieków oraz erozji wewnętrznej w ziemnych budowlach piętrzących, takich jak zapory ziemne, wały kanałów i wały przeciwpowodziowe. W artykule przedstawiono najistotniejsze zagadnienia rozwoju tej metody i jej wdrożenia w Polsce. Opisano jej podstawy oraz aplikacje pilotażowe na istniejących i nowo budowanych zaporach i wałach w Polsce, z zastosowaniem termicznych czujników do pomiarów liniowych, jak wielopunktowy czujnik MPointS oraz kable światłowodowe. Przedstawiono także rozwinięcie metody termohydraulicznego modelowania numerycznego do bardzo dokładnego określania geometrii poszczególnych stref i wartości współczynnika filtracji w przekroju istniejącej zapory ziemnej, w tym identyfikacji stref procesu erozyjnego.

9

Diachronic and historical evolution of the Al-Hoceima Bay coastline, Moroccan Mediterranean Sea

Lamgharbaj Mustapha, Etebaai Issam, Taher Morad, Ed-Dakiri Soukaina, El Moussaoui Said, El Talibi Hajar, Abdellaoui Benyounes, Cherkaoui Dekkaki Hinde

Journal of Water and Land Development

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2024

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no. 63

55--66

EN

Al-Hoceima Bay, located on the northern coast of Morocco, holds significant environmental importance. It also faces environmental challenges, including the pressures resulting from urban sprawl and growing number of tourists, as well as the impacts of climate change. The objective of this study is to assess the coastal changes in Al-Hoceima Bay since 1964, considering both natural and human factors. This study is based on the diachronic analysis of aerial photographs taken over a period of 56 years, utilising the digital shoreline analysis system statistical technique to calculate the shoreline’s mobility index for each period. The results demonstrate significant erosion at the Tayth beach (-1.50 m∙y-1) and Souani beach (approximately -1.90 m∙y-1), whereas accretion was experienced at the Sfiha beach at a rate of about +1.11 m∙y-1 and at the Lharch beach at a rate of +0.92 m∙y-1. The mouth of the Nekôr River experienced the highest retreat at -3.15 m∙y-1, followed by Ghiss at -2.00 m∙y-1. These findings indicate the impact of human interventions, such as the construction of the Mohamed Ben Abdelkarim El Khattabi dam on Oued Nekôr since 1981, as well as climate changes that have led to decreased flow, particularly at Oued Ghiss. These combined climatic and anthropogenic impacts have exacerbated erosion and disrupted the sediment balance along the shoreline of Al-Hoceima Bay.

10

Assessing the Possibility of Use Waste Rock Dumps as Elements of Ecological Network to Deter Agricultural Land Degradation and Promote Biodiversity in Mining Regions

Zubov Anton, Zubova Liliya, Aleksei Zubov

Journal of Ecological Engineering

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2024

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Vol. 25, nr 11

152--164

EN

The paper considers the methodological approaches to the use of waste rock dumps of mining enterprises as elements of regional ecological networks. Such use of dumps will promote their biological reclamation and application of measures aimed at prevention of erosion and pollution of soil cover of agricultural lands located in the zone of influence of dumps. The aim of the research was to develop a methodology for the selection of waste dumps for their inclusion in the ecological networks of Ukraine. The objects of the research were waste dumps of coal mines of the Donetsk coal basin (Donbas). The main research method is the analysis of space images using Google Earth tools. It is shown that in the conditions of the lack of forest and land resources, waste dumps can be used in the ecological network of coal mining districts and towns not only as “restorable territories”, i.e. reserve territories, but also as “interactive elements” of “key territories” (“natural kernels”) and ecological corridors. A three-stage scheme for assessing the suitability of waste dumps as elements of the ecological network is proposed, which includes 3 indicators of the suitability of dumps for the requirements of restorable territories, 2 indicators of the suitability for the requirements of kernels, and 2 indicators of the suitability for the requirements of interactive elements. The system of evaluation of dumps in points for their ranking by the order of their inclusion in the schemes of the local ecological network is developed. Biological engineering measures have been proposed to better integrate the dumps into the local ecological network. These measures will result in improved protection of agricultural land from pollution, water and wind erosion.

11

Monitoring Coastal Erosion and Deposition in Sam Son City, Vietnam – a Contribution from Remote Sensing Data

Pham Lan Thi, Le Dung KLim, Tong Son Si, Le Ha Thi Thu

Inżynieria Mineralna

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2024

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Vol. 2, no. 1

79--87

EN

Studying the trends in shoreline erosion and accretion is essential for a wide range of investigations conducted by coastal scientists, and coastal managers. Shoreline erosion and accretion occur as a result of both natural and human influences. Some areas along shoreline in Sam Son are eroded and deposed by natural coastal processes and human actions, such as storm, wave, tourism activities. Purpose of this work is to study the erosion and deposition in Sam Son over 33 years (1989–2022). Coastlines were extracted using multi-temporal Landsat images, and the shoreline change rate was determined using Digital Shoreline Analysis Systems (DSAS). The results of this paper inlustrated that the shoreline change in Sam Son undergoes significant and varied fluctuations across different areas. At the Hoi estuary, erosion rates vary from -2.22 m/year to -40.32 m/year. The construction of FLC Sam Son is one of the factors contributing to sedimentation loss in the northern part of Sam Son City, which is situated adjacent to the East Sea and next to the Ma River. Furthermore, the accretion rate has strongly increased, reaching 9.7 m/year in the Do River estuary. The phenomenon of sediment deposition serves as the basic for constructing hotels to cater to tourism in Sam Son.

PL

Badanie trendów erozji i akrecji linii brzegowej jest istotne dla szerokiego zakresu badań prowadzonych przez naukowców nadmorskich i menedżerów wybrzeża. Erozja i akrecja linii brzegowej występują zarówno w wyniku procesów naturalnych, jak i wpływu człowieka. Pewne obszary wzdłuż linii brzegowej w Sam Son ulegają erozji i akrecji w wyniku naturalnych procesów przybrzeżnych i działań ludz-kich, takich jak burze, fale, działalność turystyczna... Celem tej pracy jest zbadanie erozji i akrecji w Sam Son na przestrzeni 33 lat (1989–2022). Linie brzegowe zostały wyodrębnione z wykorzystaniem wieloczasowych obrazów satelitarnych Landsat, a wskaźnik zmian linii brzegowej został określony przy użyciu systemów cyfrowej analizy linii brzegowej (DSAS). Wyniki tej pracy ilustrują, że zmiany linii brze-gowej w Sam Son podlegają znacznym i zróżnicowanym fluktuacjom w różnych obszarach. W ujściu rzeki Hoi wskaźniki erozji wahają się od -2,22 m/rok do -40,32 m/rok. Budowa FLC Sam Son jest jednym z czynników przyczyniających się do utraty osadów w północnej części miasta Sam Son, która sąsiaduje z Morzem Wschodnim i rzeką Ma. Ponadto, wskaźnik akrecji znacząco wzrósł, osiągając 9,7 m/rok w ujściu rzeki Do. Zjawisko osadzania się osadów służy jako podstawa do budowy hoteli obsługujących turystykę w Sam Son

12

Reliability Assessment of Gored Elbow in Erosive Two-Phase Flow with Sand Particles

Khan Nauman, Khan Rehan, Wieczorowski Michał, Alnaser Ibrahim A., Seikh Asiful H, Haji Ya Hamdan

Eksploatacja i Niezawodność

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2024

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Vol. 26, no. 3

art. no. 190362

EN

Erosion, a major threat to the safety and reliability of piping components, can significantly impact their integrity and functionality. This study employs computational fluid dynamics (CFD) to systematically investigate the erosion behavior of four elbow designs (standard 90- degree elbow, 18-degree gored elbow, 22.5-degree gored elbow, and 30- degree gored elbow) subjected to multiphase air-sand and water-sand flows. Our primary objective is to identify the optimal elbow design that effectively mitigates erosion and enhances the safety and reliability of piping systems. Our findings reveal that the 22.5-degree gored elbow exhibits significantly lower erosion rates compared to other designs, particularly in air-sand flows, making it the superior choice for reducing erosion by up to 32% compared to the standard elbow. However, the standard 90-degree elbow demonstrates greater erosion resistance in water-sand flows. This research contributes valuable insights for selecting the optimal elbow design in multiphase flow, ultimately enhancing the design and longevity of piping systems.

13

Estimating Soil Erosion and Sediment Yield Using GIS in the Central Pre-Rif (Northern Morocco) – The Case of the Oued Lebene Watershed

El Amarty Fahed, Lahrach Abderrahim, Benaabidate Lahcen, Chakir Afaf

Ecological Engineering & Environmental Technology

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2024

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Vol. 25, iss. 8

1--16

EN

The alarming degradation of soils, particularly in the Moroccan Rif region, is the result of various forms of water erosion processes, leading to significant environmental and economic damage in the area. The Oued Lebene watershed is a sub-basin of the Sebou River, located in the central part of the Pre-Rif. Using GIS, remote sensing, and the universal soil loss Equation modified for North African conditions and validated by field observations, this study aimed to measure soil losses, sediment delivery capacity, and sediment yield rates. The estimation of soil loss reveals that the watershed is exposed to a high degree of erosion, reflected by an estimated total annual loss of 6 379 314 t/yr, with an average annual rate of 46.17 t/ha/yr. The severe erosion class covers 52.25% of the study area, contributing to 90.67% of sediment production with an average of 80.11 t/ha/yr-1. The erosion class below the tolerance threshold according to Wischmeier represents 48 108 hectares, or 34.82% of the total watershed area. Analysis of the synthetic sediment delivery ratio (SDR) map shows that the sediment delivery capacity is approximately 0.17, and the sediment yield (SY) in the Oued Lebene watershed is estimated at 770 440.32 t/yr. This is the outcome of the interaction between multiple causative factors, including steep slopes, friable substrates, severely degraded vegetation cover, etc., which increasingly accelerate the degradation of water resources in the downstream Oued Sebou, a source of irrigation for agricultural lands.

14

Diachronic Study of the North Atlantic Coast of Morocco between Larache and Moulay Bousselham – A Geometric Approach

El Idrissi Soukaina, Zerdeb Oumaima, Labriki Allal, Mehdioui Sakina, El Omari Mariyam, Chakiri Saïd, Inekach Sultana

Ecological Engineering & Environmental Technology

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2024

|

Vol. 25, iss. 6

90--103

EN

Coastal areas, vital for local communities, are subject to significant changes requiring rigorous management. This study focused on assessing the evolution of the Atlantic coastline between Larache and Moulay Bousselham over a period of 60 years, with an emphasis on erosion and accretion risks. The main objective was to understand coastal change trends and identify the most vulnerable areas. Using advanced techniques such as multi-temporal photo interpretation, geographic information system (GIS), and the digital shoreline analysis system (DSAS), the aerial and satellite images from 1963, 1991, 2014, and 2023 were analyzed. The results reveal that zones A (Msitro Beach) and B (Lhayayda Beach) are primarily affected by erosion, with minimal accretion, while zones C (Mersat lghnem beach) and D (Moulay Bousselham Beach) exhibit more intense erosion. This study provides an original contribution by combining advanced analytical methods to inform on the sustainable management of coastal resources.

15

Assessment of Torrential Correction Thresholds on Ourika Sub-Watershed of the Tensift Watershed (High Atlas of Marrakech, Morocco)

L’Arfouni Ilham, Algouti Ahmed, Algouti Abdella, Es-Sadiq Rachid

Ecological Engineering & Environmental Technology

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2024

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Vol. 25, iss. 7

171--185

EN

The Ourika sub-watershed is composed of about twenty different watersheds with diverse lithology, slope, and structural organization. In order to better characterize the basin, we inventoried and extensively assessed the different types of thresholds implemented in each micro-watershed. The present study focused on the area located between Meltsen and Sidi Ali Oufarés faults, which includes several micro-watersheds that have been modified by the installation of structures. We selected 12 micro-watersheds from the main tributaries draining this zone, based on the level of risk: four micro-watersheds on the right bank from upstream to downstream (Wigrane and Walighane, Tachmacht, and Touggalkhir), and eight micro-watersheds on the left bank from upstream to downstream (Imintaddarte, Oussane, Tikhfert, Tighazrit, Igri Foudene, Asni, Taljarft, and Tarzaza). The results of our study allowed us to detect and inventory 545 erosion protection structures made of masonry, gabions, and dry stone. However, the majority of these structures were damaged in several micro-watersheds due to steep slopes, torrential rainfall, and especially the solid sediment load resulting from the erosion of easily erodible old alluvial cones. This study serves as a warning to various stakeholders and decision-makers to ensure proper management in this mountainous system. The distribution of these thresholds is as follows: 62 masonry thresholds, accounting for 13.37%; 247 gabion thresholds, accounting for 45.32%; and 236 dry stone thresholds, accounting for 43.30%. The assessment of these structures revealed anomalies such as the loss of 17.43% of embankment structures and the destruction of certain thresholds.

16

Application of the interval approach to determine the exploitation time of pipelines

Duszyńska Iwona, Krykowski Tomasz, Stefanek Paweł, Bzówka Joanna

Archives of Civil Engineering

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2024

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Vol. 70, nr 1

325--335

EN

The fundamental problem from the point of view of pipeline exploitation in KGHM Polska Miedz S.A. is the very high overwearing of the pipes used for the transport of tailings, as well as determining the time of trouble-free operation of pipe system components. Failures involve significant financial outlays, severe restrictions on operation and in some cases even stopping operation. For this reason, it is vital to monitor the condition of the transport systems, as well as to determine the permissible service life of the pipe sections, after which segments at risk should be replaced or turned over in order to extend their further operation. This paper focuses on the application of interval numbers to assess the durability of piping systems. The calculations were made using classical interval numbers by using code written in INTLAB libraries. The correctness of the solutions obtained was verified using the Monte Carlo method, assuming a uniform distribution of random variables.

PL

Problemy erozji rur spowodowane transportem materiału zawierającego odpady poflotacyjne stanowiące mieszaninę frakcji pyłowej, piaskowej i iłowej stanowią bardzo ważny problem w zakresie eksploatacji kopalń i zakładów wydobywczych rudy miedzi. W odniesieniu do KGHM Polska Miedź S.A. problem odnosi się do eksploatacji rurociągów o łącznej długości przekraczającej 250 km, a to z kolei przekłada się na znaczne ponoszenie nakładów finansowych, związane z kosztami eksploatacji rurociągów, jak i ich awariami. Fundamentalnym problemem z punktu widzenia eksploatacji rurociągów w KGHM Polska Miedź S.A. jest bardzo duże zużycie rur do transportu odpadów poflotacyjnych, jak również określanie czasu bezawaryjnej pracy elementów konstrukcji systemu rur. Awarie wiążą się ze znacznymi nakładami finansowymi, poważnymi ograniczeniami w eksploatacji oraz w niektórych przypadkach, nawet z zatrzymaniem eksploatacji. W pracy skupiono się na zastosowaniu równań teorii powłok w ujęciu przedziałowym do oceny trwałości systemów orurowania. Obliczenia wykonano stosując klasyczne modele interwałowe z zastosowaniem bibliotek INTLAB. Poprawność otrzymanych rozwiązań weryfikowano stosując metodę Monte-Carlo przy założeniu jednostajnego rozkładu zmiennych losowych.

17

Submerged surface texturing of AISI 304L using the pulsating water jet method

Stolárik Gabriel, Klichová Dagmar, Poloprudský Jakub, Chlupova Alice, Nag Akash, Hloch Sergej

Archives of Civil and Mechanical Engineering

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2024

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Vol. 24, no. 4

art. 207, 1--21

EN

Submerged jets have a variety of practical applications due to their versatility in providing efficient and environmentally friendly options for treatment in various industries. The physical background is based on the continuous water jet (CWJ) application powered via stagnation pressure. However, it is known that impact pressure is much more effective than static pressure. When the impact pressure is repeated with a high frequency per time unit, the erosive effects of water can be used even at pressures below 100 MPa, which is attractive from the point of view of the low demands of the hydraulic system. Surface modification utilising impact pressure can be achieved by employing the pulsed water jet (PWJ) method. The combination of parameters such as the traverse speed and trajectory pattern can control the number of water clusters impacting the material surface. So far, the field of application of PWJ for surface treatment has mostly been investigated water atmospheric conditions. This article focuses on the possibility of the surface modification of AISI 304L stainless steel using the PWJ method under submerged conditions. The results are compared to those obtained under atmospheric conditions. The reference samples were treated by the same technological conditions using a continuous water jet (CWJ). The affected surfaces were characterised using a real surface roughness parameters Sa , Sz , Sp , and Sv, and the surface topography and mechanism of erosion wear were evaluated by scanning electron microscopy. A significant increase in all roughness parameters was confirmed using the PWJ compared to the CWJ method (both in atmospheric and submerged conditions), which confirms the importance of using impact pressure. The surface treatment by PWJ under submerged conditions resulted in a decrease of the surface roughness parameter Sa by approximately 97% compared to atmospheric conditions at a traverse speed of 2 mm/s for perpendicular interleaved trajectory, nevertheless, the homogeneity of treatment over a larger area was improved.

18

The Effect of HVOF Spray Distance on Solid Particle Erosion Resistance of WC-based Cermets Bonded by Co, Co-Cr and Ni Deposited on Mg-alloy Substrate

Jonda Ewa, Łatka Leszek, Lont Aleksandra, Gołombek Klaudiusz, Szala Mirosław

Advances in Science and Technology. Research Journal

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2024

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Vol. 18, no. 2

115--128

EN

Magnesium alloys are very interesting engineering materials because of their high strength-to-density ratio. On the other hand, they are characterized by low hardness as well as low erosion resistance. Because of these reasons, their applications in the industry are very limited. The article presents the results of the high velocity oxy-fuel (HVOF) spraying of the hard cermet coatings onto AZ31 magnesium alloy substrate. Three feedstock powders were used in the process with composition (wt.%): WC-12Co, WC-10Co-4Cr and WC-20Cr3C2Ni. The spray distance (SD) was selected as a variable parameter with values equal to 320 and 400 mm. Observations carried out under a scanning electron microscope (SEM) revealed a typical HVOF-sprayed microstructure with a compact structure and low porosity (below 3 vol.%). The hardness of the manufactured coatings, ranging from 912 HV0.2 to 1328 HV0.2, what was significantly higher than the substrate. The solid particle erosion tests were carried out according to the ASTM G76-04 standard. Erosive experiments were done for 30°, 60° and 90° inclination angles of the nozzle using Al2O3 abrasive. Erosion tests confirm that cermets exhibit substantial erosion resistance better than the substrate. The highest erosion resistance was noted for WC-10Co-4Cr coatings. The erosion rate for cermet coatings was mostly below 0.9 mg/min, whereas for the AZ31 it was more than 1.5 mg/min. In the case of the average erosion value, it was between 12 and 22 times lower than for the substrate. Results analysis reveal that shorter spray distance decreases porosity, increases hardness, and finally supports erosion resistance of the cermets.

19

Revised holostratigraphy of the Tithonian-Berriasian transition at Tré Maroua (Le Saix, Hautes-Alpes, SE France): study of a rejected Berriasian GSSP candidate

Granier Bruno R.C., Benzaggagh Mohamed, Ferry Serge

Volumina Jurassica

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2023

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Vol. 21

1--18

EN

The study of the Tithonian and lower Berriasian succession of Le Saix (Hautes-Alpes, France) has made it possible to better characterize the lithological succession at a former Berriasian GSSP candidate, its set of microfacies, the stratigraphic ranges of the main groups of marine plankton and therefore the calpionellid and saccocomid biozonations. On the lithological level, the Tithonian strata are characterized by thick-bedded breccias representing debris flows and related calciturbidites, whereas the Berriasian strata are typically white limestones. The lower part of the Berriasian is comprised of scattered intercalations of thin-bedded breccias and calciturbitides (including cryptic mud calciturbidites). In thin sections, the white limestones display mud- to wackestone textures and their allochems are mostly tiny bioclasts (e.g., radiolarians, calpionellids, saccocomids). Calciturbidites have wacke- to grainstone textures and their allochems are mostly pseudointraclasts and extraclasts, comprising various bioclasts and some ooids. Mud turbidites are made of micrograin-stones some yielding almost exclusively well-sorted calpionellids, which were previously erroneously interpreted as the signature of “explosions” or “blooms” of Calpionella alpina. Breccias are mostly lithoclastic floatstones with a matrix similar to that of the calciturbid- ites. Their lithoclasts are either extraclasts sensu stricto, i.e., material derived from updip shallow-water areas, or pseudointraclasts representing reworked subautochthonous material, i.e., mud- and wackestone lithoclasts with radiolarians, saccocomids and/or calpionellids. Radiolarians are common over the whole studied interval. Saccocomids are part of the dominating biota reported from the lower and lower upper Tithonian interval whereas calpionellids replace them in the uppermost Tithonian to lower Berriasian interval. Minor plank- tonic groups comprise calcareous dinoflagellates and Globochaete alpina; Iranopsis nov. group is also present. Intervals with saccocomid sections characteristic of zones 4-5 and zone 6 are respectively ascribed here to the lower Tithonian (4-5) and the lower upper Tithonian (6). The biozonation of the calpionellid group sensu lato allows identification of i) the Boneti Subzone of the chitinoidellids, ii) the Cras- sicollaria Zone, more specifically its Tintinnopsella-Intermedia (A1), Intermedia-Alpina (A2) and Brevis-Massutiniana (A3) subzones, and iii) the Alpina Zone, with its Alpina-Parvula (B1) and its Alpina-Remaniella (B2) subzones. On the basis of biostratigraphical and sedimentological data, most zonal boundaries prove to be hiatal, located at the erosional base of breccia or turbidite layers whereas the Tithonian/Berriasian stage boundary appears to be located at a strike-slip fault plane in the Tré Maroua section.

20

Quantification of solid particle transport in suspension in a stream : Case of Wadi Zeddine Ain-Defla, Algeria

Bouleknafet Zohir, Elahcene Omar

Journal of Water and Land Development

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2023

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no. 56

102--108

EN

Arid and semi-arid areas are characterised by differentiation in meteorological conditions. Sometimes the rains are rare and not very intense and at other times they are dense and very intense, resulting in torrents that often lead to strong soil erosion. Most of the time, the losses occur at the solids level because the erosion effect is too high. In this study, we want to evaluate the transfer of solid sediments as a function of liquid transport in the basin of Wadi Zeddine at Ain Defla in Algeria. To understand this phenomenon, we used the data of liquid flows (Ql, m3∙s-1) and concentration of suspended sediments (C, g∙dm-3), transported in the river, the data collected by the NWRA (National Water Resources Agency), over 24 years have been used to find a relationship between these two quantities, to estimate the quantity of solid transport Qs (kg∙s-1) in the watercourse of the catchment area studied. The results obtained show a good correlation between solid and liquid flows, with a correlation coefficient estimated at 90%, and the average annual sediment supply recorded at the outlet of the Wadi Zeddine watershed is estimated at around 88,048 Mg, which corresponds to 202 Mg∙km-2∙y-1 erosion rate. This value is comparable to those found in other regions with similar hydrological regimes.