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1
Content available Problematyka badań współczynnika filtracji w aparacie trójosiowego ściskania
Kaczmarek Łukasz, Dąbska Agnieszka, Popielski Paweł
Przegląd Geologiczny
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2022
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Vol. 70, nr 5
417--423
EN
Laboratory tests, which enable determination of the permeability properties of soil, are distinguished by the accuracy and relatively shorttesttime. Moreover, laboratory methods using a triaxial compression apparatus expand capability for tests with a different filtration regime and a spatial stress state applied on the analysed material. Such flexibility of research procedures allows for a number of scientific and engineering applications. The article outlines the construction of the triaxial apparatus system dedicated to filtration tests, their procedure, and important interpretation aspects.
2
Content available Krótki przegląd badań współczynnika filtracji gruntów
Popielski Paweł, Dąbska Agnieszka, Kaczmarek Łukasz
Przegląd Geologiczny
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2022
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Vol. 70, nr 5
410--416
EN
Many research methods enable the determination of the permeability properties of the soil. These methods differ, inter alia, in accuracy, complexity, application ranges, and technical conditions. The choice of a particular method is often dictated by the purpose of determining the hydraulic conductivity. The review of the most popular methods facilitates the optimization of the selection, as well as the application of mutually verifying methods or using them at different stages of the research. The article summarizes selected methods of determining the soil hydraulic conductivity from common research groups, including correlation, laboratory, and field methods, as well as less frequently used geophysical methods.
3
Content available Calculation model of pipeline resistance for cemented paste backfill considering thixotropy
Chang Yingjie, Zhang Youzhi, Gan Deqing, Wang Xinyi, Du Shuangcheng
Archives of Mining Sciences
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2022
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Vol. 67, no. 2
303--316
EN
The rheological behaviour of cemented paste backfill (CPB) has an important influence on the stability of its transportation in pipelines. In the present study, the time-dependent rheological behaviour of CPB was investigated to elucidate the effects of time and solid content. Experimental results showed that when CPB is subjected to a constant shear rate, the shear stress gradually decreases with time before finally stabilis ing. When the solid content was 60%~62%, a liquid network structure was the main factor that influenced the thixotropy of CPB, and the solid content had less influence. When the solid content was 64%~66%, a floc network structure was the main factor that influenced the thixotropy of CPB, and the solid content had a more significant influence on the thixotropy than the shear rate. The initial structural stability of CPB increased with the solid content, and this relationship can be described by a power function. Based on the experimental results, a calculation model of pipeline resistance considering thixotropy was proposed. The model was validated by using industrial experimental data. The current study can serve as a design reference for CPB pipeline transportation.
4
Content available remote Analiza zmian gradientu hydraulicznego w charakterystykach przepływu słabonośnego podłoża
Malinowska E., Szymański A.
Przegląd Naukowy Inżynieria i Kształtowanie Środowiska
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2009
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Vol. 18, No. 4
35--47
PL
W artykule przeanalizowano zmiany wartości gradientu hydraulicznego w zależności od wartości przyłożonego obciążenia zewnętrznego na słabonośne podłoże organiczne. Analizę zmian przedstawiono w funkcji prędkości przepływu wody oraz wskaźnika porowatości, którego wysoka początkowa wartość, jak wykazały badania w podłożu torfowym, znacząco maleje wraz we wzrostem naprężeń konsolidacyjnym. Analizę przeprowadzono na wynikach badań przepływu wody w słabonośnym ośrodku porowatym wykorzystując metodę flow-pump, tj. stałego, wymuszonego przepływu.
EN
In this review paper the changes of hydraulic gradient in the flow characteristics is presented. The analysis has been obtained in the value of loaded effective stress in soft soil. The relationship between fl ow velocity and hydraulic gradient is nonlinear. The results of soft soils used to the analysis were obtained in laboratory using the flow-pump technique. To describe the permeability characteristics the prelineary and postlineary phases should be considered. The prelineary phase characterises the flow at very low hydraulic gradient which usually appears in situ. The permeability characteristics show the strong changes of hydraulic gradient under different values of effective stress.
5
Content available remote Zmiana współczynnika filtracji układu piasek średni-geowłóknina K 500
Wojtasik D., Krzywosz Z.
Przegląd Naukowy Inżynieria i Kształtowanie Środowiska
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2005
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Vol. 14, No. 1
169--178
EN
The paper presents the results of laboratory tests carried out in the modified soil-geotextile permeametr (Fig. 1) recommended in ASTM standard D 5101-90. Laboratory tests were performed on nonwoven geotextile K-500 (Tab. 1) and medium sand (Tab. 2). In ftgures 2 and 3 the change in permeability coefficient in soil-geotextile system and soil under different hydraulic gradients are shown. The relationship for the evaluation of the change in coefficient in soil-geotextile system based on the initial values of the permeability coefficient of geotextile and soil as well as hydraulic gradient is proposed.
6
Content available remote Zmiana współczynnika filtracji w układzie grunt-geowłóknina
Lechowicz Z., Krzywosz Z., Wojtasik D.
Przegląd Naukowy Inżynieria i Kształtowanie Środowiska
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2003
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Vol. 12, No. 2
38--47
EN
The paper presents the results of laboratory tests carried out in the modified soil-geotextile permeameter (Fig. 1) recommended in AST Mstandard D 5101-90. Laboratory tests were performed on nonwoven geotextile K-500 (Tab. 1) and clayey sand (Tab. 2). In Figures 2 and 3 the change in permeability coefficient in soil-geotextile system and soil under different hydraulic gradients are shown. The relationship for the evaluation of the change in permeability coefficient in soil-geotextile system based on the initial values of the permeability coefficient of geotextile and soil as well as hydraulic gradient is proposed.
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