Numerical 2D Simulation of Morphological Phenomena of a Block Ramp in Poniczanka stream: Polish Carpathians

Description of flow in streams is a very complex problem. Physical analyses of this phenomenon provide a quantitative description of water flow, allowing creating mathematical models having practical meaning. Fast development of programs has improved their practical implementations, so the results of analyses and solutions of flow problems in both open channels and pipes, obtained through numerical modelling, can be applied in practical solutions. Numerical models are often very useful in studies covering a wide range of analyzed parameters. However one must understand that the similarity between a real river and its model could only be partially verified. The main purpose of this paper is to investigate the effect of the selected boulder block ramp hydraulic structure on Poniczanka stream on sediment transport, using the numerical model CCHE2D, assuming several situations, depending on the type of the river bed (erodible, non-erodible, rocky) and kind of rock blocks used for hydraulic structure construction. The obtained results were compared with the Hjulström graph, which is a classic approach for the identification of fluvial processes in the river channel (erosion, sedimentation, transport). In addition to these two methods, field observations were carried out which included the determination of changes in the horizontal and vertical changes of the riverbed morphology of the examined section river reach. The obtained results allowed determining the compatibility of these three methods for evaluation of sediment transport rate of river bed material in the analyzed sections of Poniczanka stream which are engineered with boulder block ramp hydraulic structures (BBR)

Vibration induced by railway traffic-zones of influence on buildings and humans

The article presents selected results of evaluation of the harmfulness of buildings vibrations and influence on humans in buildings caused by railway traffic. The results presented in the paper were part of larger group of in field test which gather, were the basis of creation the zones of influence of railway vibrations. The paper presents the methodology of field test as well as some selected results. The discussion of the results leads to conclusions which are presented, as mentioned above, zones of influence of railway vibrations on building construction as well as on human in the buildings. The proposed zones are different for cargo and passenger trains. The ranges of zones are also different in case of building structure and human perception. All analyzes are compatible with polish codes PN-B-02170:2016 [1] and PN-B-02171:2017 [2] and executed by accredited laboratory with significant participation of the authors. The proposed zones were assumed by manager of the national railway network PKP PLK S.A

Rozkład prędkości oraz naprężeń stycznych w komorach przepławki typu wielko-komorowego

W pracy przeanalizowano rozkład prędkości i sił w postaci naprężeń stycznych działających w komorach przepławki dla ryb. Do analizy wybrano dobrze działającą przepławkę wielko-komorowa skonstruowaną na potoku Wierchomlanka w miejscowości Wierchomla. Przepławka ta, o wymiarach komór 2,40 x 4,80 m , podczas stanów średnich i niskich umożliwia bezproblemową migrację różnym gatunkom ryb w górę strumienia, a we wnętrzu jej komór ryby znajdują miejsce na odpoczynek przed podjęciem kolejnego przejścia z komory do komory. Praca jest adresowana do inżynierów środowiska, projektantów budownictwa wodnego oraz ekologów pracujących z potokami górskimi

Dominant discharge – an outline of theory and a case study from the Raba river

Designing hydraulic structures engineers has only theoretical flows, calculated using formulas based on statistics. Knowledge of the dominant discharge could help determine designers who are interested in changes of the morphology of river channels, especially in terms of sediment transport. It was observed that the designing of a stable channel in the river is possible when defining characteristic of flow in the river which is the most frequently present in the river and in the same time it carries the sediment. That is the dominant discharge. It is this movement can represent both the hydraulic system and the geometry of the river cross-sections. The dominant discharge (also called river shaping channel discharge) is considered by many authors as a discharge that transports the largest amount of sediment, it takes a long time and has an impact on the formation of the shape of the river bed. Observations of Wolman and Miller showed that low but frequent flows of water might be responsible for new shape of the river channel, erosion of the riverbed, sediment deposition and consequently changes in river morphology. The paper presents Wolman method for dominant discharge use for the Raba River for chosen gauge cross section. Along in the paper we discuss the obtained results and the consequences of using dominant discharge for the practice. In six cross sections on the Raba River, Qdd was calculated values, which range from 31 m3 • s–1 (for the section in Rabka) to 395 m3 • s–1 (in Proszówki). These flows occur every two years (for the upper sections of the river), and every four years (for cross-sections located in the lower section of the river)

Bed-Load Transport in Two Different-Sized Mountain Catchments: Mlynne and Lososina Streams, Polish Carpathians

The prediction and calculation of the volume of gravel and/or sand transported down streams and rivers—called bed-load transport is one of the most difficult things for river engineers and designers because, in addition to field measurements, personnel involved in such activities need to be highly experienced. Bed-load transport treated by many engineers marginally or omitted and often receives only minor consideration from engineers or may be entirely disregarded simply because they do not know how to address the issue—in many cases, this is a fundamental problem in river management tasks such as: flood protection works; river bank protection works against erosion; building bridges and culverts; building water reservoirs and dams; checking dams and any other hydraulic structures. Thus, to share our experience in our paper, bed-load transport was calculated in two river/stream mountain catchments, which are different in terms of the characteristics of the catchment area and the level of river engineering works performed along the stream channel—both are tributaries of the Dunajec River and have similar Carpathian flysh geology. The studies were performed in the Mlyne stream and in the Lososina River in Polish Carpathians. Mlynne is one of the streams in the Gorce Mountains—it is prone to flash flooding events and has caused many problems with floods in the past. It flows partially in the natural river channel and partially in a trained river channel lined with concrete revetments. The stream bed load is accumulated in the reservoir upstream of the check dam. The Lososina River is one of the Polish Carpathian mountainous streams which crosses the south of the Beskid Wyspowy Mountains. It mostly has a gravel bed and it is flashy and experiences frequent flooding spring. At the mouth of the Lososina River, there is one of the largest Polish Carpathian artificial lakes—the Czchow lake. The Lososina mostly transports gravel as the bed load to the Czchow water reservoir where the sediment is deposited. In the early seventies, the Lososina was partly canalised, especially in places where passes inhabited areas. The paper compares the situation of bed-load transport in the Lososina River before and after engineering training works showing how much sediment is transported downstream along the river channel to the Czchow artificial lake. Also compared is the Mlynne bed load transport upstream and downstream from the check dam showing how much sediment might be transported and deposited in the reservoir upstream from the check dam and when one could expect this reservoir to be clogged

Wybrane problemy eksploatacyjne bystrzy o zwiększonej szorstkości (stopni-ramp) w aspekcie ich projektowania i funkcjonalności biologicznej

W pracy przedstawiono wybrane problemy budowy i eksploatacji bystrzy o zwiększonej szorstkości zwanych inaczej stopniami-rampami, skupiając się głównie na trzech obszarach tematycznych: stanowisku górnym bystrza, stanowisku dolnym bystrza, płycie spadowej z głazami oraz gurtach obiektu. Podano wnioski co do prawidłowego projektowania bystrzy, jak i przykłady z praktyki inżyniersko-wykonawczej oraz badań. Zwrócono uwagę na możliwości zasiedlenia bystrza przez bezkręgowce wodne, a także na konieczność zapewnia w projekcie ciągłości ekologicznej w niskich stanach wody

Podsypka filtracyjna a narzut kamienny ubezpieczający brzegi cieków górskich

W pracy przeanalizowano grubości kamieni użytych do budowy ubezpieczenia w postaci narzutu kamiennego oraz jego podsypki na dwóch obiektach w okolicy Starego Sącza oraz we wsi Głębokie (w trakcie budowy). Zestawienie poszczególnych pomiarów i przedstawienie tych wyników w postaci krzywych przesiewu, a następnie sprawdzenie warunków stateczności i przepuszczalności pozwalają określić, czy parametry charakteryzujące rozmiar podsypki i kamienia łamanego budującego umocnienie zostały poprawnie dobrane. Pomiary narzutów i podsypki wykonano za pomocą metody Wolmana – pomierzono 600 próbek. Po wykonaniu obliczeń ustalono, że oba warunki stateczności zostały spełnione tylko przez narzut w miejscowości Głębokie, natomiast warunek przepuszczalności nie został spełniony w żadnym narzucie. Z przeprowadzonych obliczeń wynika, że konieczna byłaby zmiana kruszywa o minimalnej średnicy w podsypce filtracyjnej tak, aby został spełniony warunek przepuszczalności. Występuje tu największa różnica pomiędzy minimalnym rozmiarem spełniającym warunek a obecnie zastosowanym kamieniem łamanym. Zwiększenie tej średnicy pozwoli na spełnienie także innych warunków

Gravel and boulders mining from mountain stream beds

Mountain stream gravel is very often legally and illegally mined and gravel is removed from river beds sometimes on the very large scale which is disastrous for fluvial situation of rivers, for river ecology and river engineering works done for flood protection such as river revetments, bridges and all hydraulic structures. This situation makes a big problem for all river managers. Thus gravel mining of the mountain streams in the Polish Carpathians is the subject of many scientific studies when we observe river problems, but also it has a place in Slovakia. This paper deals with such problems additionally showing examples of such bad practices