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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.

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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.

3

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.

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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.

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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

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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.

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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.

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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

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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.

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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.

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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.

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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.

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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.

13

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.

14

Badania numeryczne wpływu erozji oraz zabrudzeń łopaty na pracę turbiny wiatrowej

Malecha Ziemowit, Sierpowski Korneliusz

Instal

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2023

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nr 7/8

7--13

PL

W pracy przeprowadzono badania numeryczne wpływu zabrudzeń, oblodzenia oraz uszkodzeń łopat turbiny wiatrowej na produkcję mocy. Przeanalizowano dwa scenariusze kontroli pracy turbiny wiatrowej, standardową oraz zaawansowaną. Kształt oblodzonych oraz uszkodzonych profili opracowano bazując na wynikach eksperymentalnych oraz obserwacjach rzeczywistych łopat turbin. Pokazano, że w przypadku turbiny oblodzonej, zabrudzonej oraz zerodowanej produkcja mocy może spaść odpowiednio o około 50%, 16% oraz 12.5%. Przeanalizowano wpływ spadku produkcji przez turbinę na współczynnik wykorzystania mocy. Na przykładzie lokalizacji na Morzu Bałtyckim, pokazano, że współczynnik wykorzystania mocy może spaść o 0.023% oraz dodatkowo o około 0.005% wraz ze zwiększeniem udziału dni z zabrudzonymi łopatami w roku o kolejne 10%.

EN

Numerical studies of the impact of dirt, icing and eroded of wind turbine blades on power production were carried out. Two scenarios of wind turbine operation control, standard and advanced, were analyzed. The shape of ice-covered and eroded profiles was developed based on experimental results and observations of real turbine blades. It has been shown that in the case of an ice-covered, dirty and eroded turbine blade, power production can decrease by approximately 50%, 16% and 12.5%, respectively. The influence of the decrease in power production on the capacity factor was analyzed. Using the example of a location in the Baltic Sea, it has been shown that the capacity factor can decrease by 0.023% and additionally by about 0.005% with an increase in the share of days with dirty blades in the year by another 10%.

15

Rainfall Erosivity Factor within the Volyn Region

Matviichuk Bogdan, Romantschuk Ludmila, Matviichuk Nataliia

Ecological Engineering & Environmental Technology

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2023

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Vol. 24, iss. 6

135--146

EN

The article presents results of the research and mathematical modelling of the rainfall erosivity factors. Erosion, whether water, wind or resulting from soil cultivation, includes three processes – soil descaling, movement and sedimentation. Spatial characteristics of precipitation during two researched periods are similar, having certain quantitative peculiar features. A common feature is maximum precipitation in the southwest and to a lesser extent in the eastern part of the region. Minimum precipitation is typical for the western part of the region. Peculiar feature of the second period of research is increase of contrasting effect of precipitation regime, when minimum values of precipitation decrease and maximum ones increase. Enhancement of contrasting effect of precipitation in space or time may cause increased intensity of erosion processes to the extent where the intensity of precipitation increases due to such contrasting effect. Thus, doubtless interest lies in the research of greater spatial or time contrasting effect of precipitation regime to activate water erosion. Thus, spatial peculiarities of distribution of precipitation within territory under study and time patterns correlate, but have their own special features. Clearly, total amount of precipitation as well as time distribution as a marker of correlation of intensification factor of erosion processes and defence mechanisms of vegetative cover are dominant for total losses of soil due to erosion. Coincidence of time of intense precipitation in summer and availability of vegetative cover reduces erosion. Nevertheless, continuance of intense precipitation when harvesting is started may cause intensification of water erosion of soil. Use of spatial variables and regression equations for spatial data calibration helped to estimate the spatial variation of precipitation on the territory under study. Comparison of two periods of research showed that in 2010–2016 significant reduction of rainfall erosivity factor has taken place in comparison with the previous period 9.6–65.4 MJ mm ha–1 h–1 per year. In Turiyskyi and Kovelskyi district changes in rainfall erosivity factor were minimal (9.6 and 16.7 MJ mm ha–1 h–1 per year respectively). Conversely, in Ivanytskyi and Gorokhivskyi districts changes were the most significant – 58.1 and 65.4 MJ mm ha–1 h–1 per year respectively.

16

Modeling Soil Erosion Using RUSLE and GIS – A Case Study of Korifla Sub-Watershed (Central Morocco)

Eddefli Fatimazahra, Ouakil Abdelhadi, Khaddari Achraf, Tayebi Mohamed

Ecological Engineering & Environmental Technology

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2023

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Vol. 24, iss. 4

128--137

EN

Soil loss is a problem that contributes to land degradation in many countries and Morocco is no exception. Our study focuses on water erosion in Korifla, a sub-basin of the Bouregreg watershed in northern Morocco. The objective is to quantify erosion using the RUSLE method which is based on five factors: Runoff erosivity, soil erodibility, cover factor, topography and conservation practices. These are processed by remote sensing and a geographic information system. The soil loss map shows that on an area of 1838 km2, erosion is estimated to be between 0.00 t/ha/year and 27.61 t/ha/year. The cumulative effect of the factors R, K, LS, C, and P are both the origin of this erosion and its spatial distribution.

17

Integration of Sentinel2 Data into a GIS System for the Mapping of Areas at Risk of Degradation by Applying the MEDALUS Model – Case of Sidi Mohamed Ben Abdellah Watershed (Morocco)

Ouakil Abdelhadi, Eddefli Fatimazahra, Ben Hichou Badr, Chao Jamal, Elbelrhiti Hicham

Ecological Engineering & Environmental Technology

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2023

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Vol. 24, iss. 7

216--228

EN

Located in the central northwest of Morocco, the Sidi Mohamed Ben Abdellah dam watershed is particularly exposed to soil degradation risk due to a combination of factors such as wide exposure, lithological heterogeneity, and varying climatic conditions. Therefore, the purpose of the conducted study was to create a spatial map of the areas most susceptible to degradation using the MEDALUS (Method for the Evaluation of the Degree of Soil Loss Susceptibility) model to pinpoint the areas that are most vulnerable to the risk of erosion. The MEDALUS model is a commonly used tool for assessing soil degradation and erosion risks. It takes into account physical, climatic, and land use factors to determine the susceptibility of an area to soil loss. To apply the model to the Sidi Mohamed Ben Abdellah dam watershed, the data on factors such as slope, soil type, vegetation cover, and precipitation would be collected, and this information would be used to generate a map of the areas at greatest risk of erosion. This map could then be used to prioritize conservation and management efforts in the watershed and identify the areas that require additional protection or restoration. The map of erosion sensitivity is produced by combining factors that contribute to the phenomenon, such as vegetation cover, climate, relief, pedology, and human intervention. Cross-referencing these factors in a GIS (geographic information system) allows generating an erosion sensitivity map that highlights the most vulnerable areas to this hazard in the region.

18

Analiza wpływu parametrów napawania laserowego LMD na wybrane właściwości napoin wytworzonych z proszku HS6-5-2c na stali 1.4923

Chrzanowski Wojciech, Napadłek Wojciech, Bogdanowicz Zdzisław

Biuletyn Wojskowej Akademii Technicznej

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2023

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Vol. 72, nr 1

116--130

PL

W pracy zaprezentowano wyniki badań napoin wytworzonych technologią napawania laserowego LMd (Laser Metal Deposition) z zastosowaniem różnych parametrów wiązki laserowej. na powierzchni podłoży ze stali 1.4923 w kształcie prostopadłościanów wytworzono napoiny wielościegowe z proszków hs6-5-2c o różnym stopniu przykrycia. W ramach prób napawania laserowego wytworzono próbki, na których następnie przeprowadzono badania topografii powierzchni, obserwacje mikrostruktury oraz pomiary twardości w poszczególnych strefach warstwy wierzchniej podłoża, to jest w strefie napoiny, strefie wpływu ciepła (sWc) oraz w strefie materiału rodzimego. obserwacjęi analizę powierzchni napoin oraz mikrostruktury w przekroju poprzecznym próbek po napawaniu LMd zrealizowano z zastosowaniem mikroskopii optycznej ze światłowodową transmisją obrazu. pomiary twardości wykonano, używając twardościomierza Vickersa FLc-50a. na podstawie obserwacji mikroskopowych stwierdzono, że uzyskane napoiny mają regularny i powtarzalny kształt. Ponadto na powierzchniach wytworzonych napoin oraz w strefie wtopienia materiału napoiny z materiałem podłoża nie zauważono występowania wad procesowych. Twardość uzyskanych napoin wynosiła 500-700 hV0,1. Wytworzone na bazie proszku hs6-5-2c napoiny poddano badaniom odporności na erozję, które wykazały znacznie wyższą odporność na zużycie erozyjne (nawet ok. pięciokrotnie) w porównaniu z materiałem podłoża (stal 1.4923) bez napawania.

EN

This paper presents the results of testing surfacings produced by LMd (Laser Metal deposition) laser deposition technology for different laser beam parameters. on the surface layer of rectangular-shaped samples, made of 1.4923 steel, multiwall surfacing was produced from hs6-5-2c powder with different degrees of coverage. as a part of the laser deposition verification and testing, surface topography, microstructure and hardness tests were carried out in the deposition zone, heat affected zone, and the zone of the parent material. The surface of the surfacing and the microstructure in cross-section were observed on an optical microscope with fibre-optic image transmission. Hardness measurements were made in the cross-section of the sample using a Vickers FLc-50a hardness tester. Based on the observations, it was found that the obtained surfacings have a regular and repeatable shape. There were no welding defects on the surfaces of the produced surfacings and in the zone of fusion of the surfacing material with the substrate material. The hardness of the surfacings was obtained in the range of 500-700 hV0.1. The surfacings produced by LMd technology were subjected to erosion resistance tests, which showed significantly higher (about 5 times higher) resistance to erosion wear of the produced surface layers (surfacings based on hs6-5-2c powder) in comparison with the substrate material, i.e., steel 1.4923.

19

Analiza procesów uszkodzeń łopat turbin parowych

Chrzanowski Wojciech, Napadłek Wojciech, Bogdanowicz Zdzisław

Biuletyn Wojskowej Akademii Technicznej

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2023

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Vol. 72, nr 2

39--63

PL

Artykuł dotyczy przeglądu literatury oraz określenia i analizy przyczyn zużycia łopat turbin parowych. W wyniku analizy stwierdzono, że głównymi przyczynami uszkodzenia łopat są procesy erozyjno-korozyjne oraz wpływ podwyższonej temperatury wewnątrz turbiny, powodujące m.in. efekt wydłużenia i odkształcenia łopat oraz występowanie pęknięć w wyniku gwałtownych zmian temperatury. Przegląd literatury i analiza zjawisk zniszczenia wykazały, że łopaty narażone są na erozję wynikającą z warunków ich pracy, w tym oddziaływania środowiska pary wodnej i/lub wtrysku kondensatu chłodzącego w strefie ostatniego stopnia części niskoprężnej turbiny. Zjawisko erozji występuje głównie na krawędziach wlotowych i wylotowych łopat, powodując oprócz zmniejszenia sprawności turbiny także efekt nierównomiernego wyważenia elementów współpracujących (różne zużycie łopat w jednym stopniu wirnika). erozja może także powodować wzrost naprężeń mogący doprowadzić do poważnych uszkodzeń nie tylko łopatek, lecz także podzespołów turbiny. Łopaty turbin parowych są narażone również na oddziaływanie agresywnych związków chemicznych (chlorki, siarczany oraz krzemiany metali alkalicznych pochodzące z pary wodnej), w wyniku których na łopatach może zachodzić korozja równomierna, a także wżerowa. Dlatego w artykule przeanalizowano wpływ warunków pracy na występujące uszkodzenia oraz możliwości związane z prognozowaniem trwałości eksploatacyjnej łopat.

EN

The article is a review of the literature data related to the wear of steam turbine blades. The literature review have found that the main causes of blade damage are erosion, corrosion, and the occurrence of elevated temperatures inside the turbine, which cause, among other things, blade elongation, deformation, and cracks due to rapid temperature changes (thermal shock). A review of the literature has shown that blades are a subject to erosion resulting from operating conditions in which the blades strike water droplets formed from steam or from the injection of cooling condensate in the zone of the last stage of the low-pressure part of the turbine. erosion occurs mainly at the inlet and outlet edges of the blades, causing imbalance (different blade wear in one rotor stage) in addition to reducing turbine efficiency. erosion can also cause an increase in stresses that can lead to serious damage not only to the blades, but also to other turbine components. Steam turbine blades are also exposed to aggressive working environment (chlorides, sulfates, and alkali metal silicates from steam) as a result of which uniform and also pitting corrosion can occur on the blades. The article also analyses the effect of operating conditions on the damage that occurs, as well as the literature on predicting turbine blade life.

20

Analysis of the pulsating properties of a high‑pressure water jet generated in a self‑excited head for erosion processing

Szada-Borzyszkowska Monika, Kacalak Wojciech, Banaszek Kamil, Borkowski Przemysław J., Szada-Borzyszkowski Wiesław

Archives of Civil and Mechanical Engineering

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2023

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Vol. 23, no. 4

art. e236, 1--16

EN

Water jet is an extensively used method for materials processing due to the possibility of operating in different environments (air, water), its safety during working with hazardous materials, and efficiency while cutting hard and brittle rock blocks. In this article, we have presented results of the research on processing aerated concrete by means of pulsating water jest. The discontinuity in water flow through the nozzle was achieved using an own-construction self-excited head. The intermittent flow had the greatest effect during operating in water environment. Machining efficiency for continuous and pulsating water jest was indicated by measuring erosive effects on processed materials. The occurrences of pulsations were confirmed while measurement of water jet thrust forces acting on piezoelectric sensor. It was concluded that pulsating water jet had greater processing effectiveness in a certain circumstances compared to the continuous flow, during the surface processing of concrete blocks.