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EN
An excavation dug out in the glacially transported rock masses at Golaszyn near Łuków (eastern Poland), revealed the presence of deposits unknown so far in this area. These are older than the only known so far here glacially transported clays containing concretions with splendidly preserved ammonites of late Callovian at Łapiguz brickyard of Łuków. The succession exposed consists of sands and sandstones of Middle Callovian age which rest on red-brownish clays. The latter may be compared with the Triassic - Buntsandstein deposits of the northwestern Lithuania, that is the home area of glacially transported rock masses, commonly occurring in eastern Poland in the Łuków area. The new geological discoveries markedly increase a set of attractions for the promotion of the Łuków region for the education and geotourism purposes.
EN
For the purpose of this paper, laboratory tests on clay samples, collected at the Słupsk Bank with the use of a vibrocorer, were carried out in the Geotechnical Laboratory of the Maritime Institute in Gdańsk. This study aims to determine the geotechnical properties of the above-mentioned soils. Oedometer and classification tests were conducted on the selected specimens. Strain properties, secondary compression index and undrained shear strength were determined for the material. The impact of vibrocoring as a sampling technique on the obtained results and recommendations for application of these results were also described.
PL
Na potrzeby niniejszego artykułu, w Samodzielnym Laboratorium Geotechniki Instytutu Morskiego w Gdańsku, przebadano próbki iłów pobranych za pomocą wibrosondy z obszaru Ławicy Słupskiej. Celem badań było określenie parametrów geotechnicznych wspomnianych gruntów. Przeprowadzono badania edometryczne oraz wykonano badania klasyfikacyjne. Dla wybranych próbek określono parametry odkształceniowe i wyznaczono współczynnik ściśliwości wtórnej oraz określono wytrzymałość na ścinanie w warunkach bez odpływu. Opisano również wpływ pobierania próbek wibrosondą na uzyskane wyniki oraz pewne zalecenia dotyczące wykorzystywania wyników.
EN
A comparative analysis of weathered marls and flysch, silty soils, illite and baidelite clays leads to the determination of a common feature of these grounds, namely the exceptional sensitivity to changes of the moisture content. From the tests performed we can state that this common characteristic is due to the presence of illite and smectite in these media. In the paper, a methodology of the swelling ability test has been proposed as a method of identification of such clay minerals. Investigation of the eluvium geotechnical parameters by "in situ" methods has also been proposed.
4
Content available remote Changes in properties of clay surrounding cast in-situ piles
EN
For piles in clay soils, the major contribution to working load capacity is from the shaft resistance, which is influenced by the types of piles used and construction methodology adopted. In the case of preformed piles, the time-related response relates to changes in pore water pressure. However, in the case of cast-in-situ concrete piles it is anticipated that changes in soil chemistry due to migration of ions from the concrete would have an effect on soil/pile interaction. A laboratory- scale test conducted to investigate change in soil chemistry with time and its impact on load carrying capacity of cast in-situ piles in Oxford clay showed that there was a short-term increase in moisture content of soil adjacent to the piles. It also showed that there was an increase in both hydroxyl and calcium ion concentration. These also affected adhesion factor, which increased with time to a limiting value.
EN
The stress-strain behaviour of tills under static and dynamic loadings were analyzed in the paper. Test results conducted on the tills from Ursynów area inWarsaw are presented. Extensive spectrum of advanced laboratory testing (including SEM, Row-Barden consolidometer, ring-shear apparatus, dynamic triaxial testing system) was used to determine physical, mechanical and microstructural properties of tills. Under static loadings studied tills have showed the behavior characteristic to overconsolidated soils. Parameters of residual shears strength are 40% lower comparing to maximum shear strength. Under cyclic loading of acceleration up to 1.5 m/s2 the failure did not appear. Cyclic loading causes a reduction in shear resistance, post-cyclic shear strength is equal to 18-76% of static (monotonic) shear strength of studied tills.
6
EN
Soil mixtures are simple and cheap solutions for bettering of soils in building engineering. They also can be used in constructing of sealing beds of landfills. Soils that may be used for mineral sealing beds of landfills must meet both official regulations and criteria elaborated by experienced researchers. Experiments showed, that minor additions of clay (or selected clay minerals) to sand can seal a loose soil without any drop in its strength abilities. Such a soil mixture is very well compactable and achieves low values of porosity, hence, low values of permeability.
EN
The qualitative and quantitative characteristics of microstructures in a till were analysed with SEM; it was also investigated whether the results depend on the till’s mesostructural characteristics. The till, exposed in a few open-cast browncoal mines near Konin in central Poland, is cut by numerous fractures which correspond to Riedel shear patterns, P-type structures and C-S type foliations. The fractures developed as a result of simple shearing induced by movement of the base of the Odranian ice sheet. On the basis of fracture density, two till types are distinguished: coarsely-brecciated till (wide spacing of fractures) and finely-brecciated till (closely spaced fractures). It is found that the fracture density is reflected in the microstructure of the till. The finely-brecciated till is characterised by a high porosity and has predominantly anisometric and fissure-like pores that also show a more clearly preferred orientation than the pores in the coarsely-brecciated till. In contrast, the coarsely-brecciated till has anisometric pores that show a less preferential orientation. The porosity of the coarsely-brecciated till is lower than in the finely-brecciated till. The finely-brecciated till probably represents a strongly deformed deposit, related in some cases to zones developed along thrusts that cut the till. Positive correlation between the porosity, the spatial arrangement of pores, and the density of fractures suggests a synsedimentary origin of the shear strain. This strain was accommodated by a particulate flow developed within both wide, pervasive zones and narrow, localised zones. The hydraulic conditions within the subglacial shear zone controlled rheological differences within the till during deformation and thus influenced the degree of the microstructure alteration.
EN
In this article, the conception of determination of permeability coefficient k based on linear segment of the settlement curve in a compression test is presented. By observing the evolution of the settlement curve of a soil, it is possible to find in its initial part a linear relation between the settlement and time. For clays, the time interval ranges from about 45 sec to a few minutes, as measured from the moment a load has been imposed. The linear character of the graph means that rheological effects are absent and that settlement velocity is constant and equal to percolation velocity. Thus, it may be supposed that within this time interval the permeability coefficient is approximately constant, too. Hence, the value of k calculated on the basis of this linear part of the settlement curve should be reliable. In this paper, the values of permeability coefficient k for clay, obtained in triaxial apparatus were compared with those obtained in oedometer test (based on the linear segment of the settlement curve). The results obtained appear to be promising. Nevertheless, since the number of tests carried out so far is rather small, it is necessary to perform more experiments to verify our conception.
10
Content available remote Znaczenie występowania glin lodowcowych Polski i Ukrainy
EN
The presence of glacial tills in eight loess type sections documenting, in most cases, a complete rhythm of climatic changes during the last 780 ka (Brunhes epoch) in Poland and Ukraine, allows to precisely establish the age of these tills. The oldest till in Odonów, Kolonia Zadębce, and Bojanice represents the Sanian 2 (Elsterian 2, Okanian) Glaciation. The younger till (in Wąchock, Gradiżsk, and Wjazowok) corresponds to the ice-sheet extent during the Krznanian (Saalian 2, Dnieper 1) Glaciation, and the youn gest till (in Wąchock, Bugaiwka, and Stajki) to the ice-sheet extent during the Odranian (Saalian 3, Dnieper 2) Glaciation. The occurrence of these glacial tills in the discussed loess sections is crucial for the correlation of glacial and extraglacial stratigraphic schemes for the Pleistocene of Europe.
EN
South Polish tills surface in downtown Wrocław were mapped using 136 records of elevation of glacial tills surface. The unevenly distributed data were interpolated by kriging method. The investigated surface a reveals a prominent upward trend in the S–SW direction (from 95 to 114–115 m a.s.l.), average inclination is 15–200o. There are some evident irregularities in that trend, e.g., a 3–4 meters deep trim in the central part of map. Modern morphology of the top surface of glacial tills (Sanian 2) is a result of fluvial erosion after Sanian 2 glaciation. Some irregularities of the surface can be an effect of the brook character of that river. Position of the Recent Odra’s riverbed is directly connected with an old Pleistocene riverbed.
EN
Lithological analysis of glacial tills is a usefull tool for investigations of marginal zones of Pleistocene glaciations. Presented documentation was based on several examples taken from selected regions of Pomerania, Northern Poland. Simultaneously, regional variability of petrographical tills com po si tion was dem on strated. Some interpretational problems caused by tills weathering are discussed.
EN
The ”Adamów–Smulsko” exposure is situated in the eastern part of Wielkopolska about 5 km to the east from Turek. Three till horizons are exposed there. The oldest one is considered to be the deposits of South Polish Glaciation age (Elsterian), the middle one of Odranian age and the upper one — divided in two strata — of Warthanian age (Klatkowa, 1993). Indicator erratics in samples taken in two profiles, lying two kilometres apart, were analysed. The relationship between fundamental indicator erratics has been determined and the comparison with the contribution of particular alimentation areas in the supply of coarse material has been made, also the theoretical home centres of the boulder associations (TGZ) here been marked. The stratigraphical conclusions do not confirm the previous interpretation. The occurrence of Odranian tills has not been supported. The lowest till horizon has been attributed to Nida Glaciation, whereas the middle and upper ones to the Warthanian Glaciation.
PL
W pracy przedstawiono interpretacje glin morenowych zlodowacenia środkowopolskiego (glacistadiału Warty) z Kożuchowa. Interpretacja oparta została na wynikach szczegółowych badań laboratoryjnych dotyczących oznaczenia granulacji (składu ziarnowego), wskaźnika plastyczności i granic konsystencji. Gliny morenowe na podstawie faktów geologicznych uznawane są za typowy produkt sedymentacji glacjalnej. Wyniki badań laboratoryjnych były przedmiotem analizy, która miała wykazać ich genezę. Wykorzystano dwie różne metody stosowane w geologii inżynierskiej i mechanice gruntów: "wykres Wiłuna" i "wykres Casagrande'a".
PL
W pracy zawarta jest analiza dotycząca interpretacji glin zwałowych występujących na północnym stoku Wału Zielonogórskiego. Gliny te powstały podczas zlodowacenia środkowopolskiego w glacistadiale Odry (G IIImax) i Warty (G III +1). Gliny zwałowe pod względem geotechnicznym są reprezentowane przez gliny piaszczyste (63% prób), gliny zwięzłe (10,9% prób) i gliny piaszczyste zwięzłe (10,9% prób) (rys.1). Przeprowadzono próbę korelacji w ustalaniu genezy gruntów w oparciu o wykresy Wiłuna i Casagrande'a. Z wykresu Wiłuna, gdzie interpretowana jest zależność Ip = f(fi) wynika, że prawie wszystkie punkty projekcyjne położone są w polu genetycznym odpowiadającym glinom zwałowym. Wniosek ten znajduje potwierdzenie w badaniach geologicznych. Interpretacja genezy gruntów oparciu o wykres Casagrande'a (rys.3 i rys.4) wskazuje, że punkty projekcyjne znajdują się w polach gliny zwałowej, lessów oraz o nieoznaczonej genezie. Można zatem wnosić, że w interpretacji Casagrande'a analizowane gliny nie znajdują w części potwierdzenia w faktach geologicznych. Autorzy są zdania, że wydzielone charakterystyczne pola genetyczne na wykresie Casagrande'a wymagają korekty. W badaniach geologicznych w tym rejonie nie stwierdza się występowania lessów podczas gdy na rys. 3 i rys.4 występują punkty projekcyjne odpowiadające lessom.
PL
W pracy przedstawiono analizę glin zwałowych oraz glin pokrywowych z okolic Głogowa w aspekcie zależności wskaźnika plastyczności od frakcji iłowej w oparciu o wykres Wiłuna, oraz zależności wskaźnika plastyczności od granicy płynności w oparciu o wykres Casagrande'a. Analizowane gliny zwałowe powstały w glacistadiale Warty zlodowacenia środkowopolskiego, tj. ok. 165-195 tys. lat BP. Gliny te pod względem geotechnicznym są reprezentowane przede wszystkim przez glinę piaszczystą (Gp) i glinę (G). [...] Z badań wynika, że na wykresach Wiłuna punkty projekcyjne tak dla gliny zwałowej jak i dla gliny deluwialnej znajdują się w polu wydzielonym jako utwory lodowcowe. Zdaniem autorów sytuacja taka wymaga korekty granic obszarów genetycznych na tym wykresie. Na wykresach Casagrand'a mamy przypadki takie, że część gruntów analizowanych znajduje się w polach o określonej genezie zaś część w polach o nieoznaczonej genezie. W związku z tym, autorzy zaproponowali pewną modyfikację granic genetycznych na wykresie Casagrande'a (rys.8).
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