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PL
Artykuł zawiera wyniki badań stabilizacji mieszaniny popiołowo-żużlowej pochodzącej ze składowiska Elektrociepłowni „Kraków”: cementem, wapnem, spoiwami Terramix F22,5 i Solitex. Badania obejmowały określenie podstawowych parametrów geotechnicznych oraz wytrzymałości na ściskanie bez dodatku spoiwa i z dodatkiem 3, 6 i 8% po 7 i 28 dobach pielęgnacji oraz po 28 dobach pielęgnacji próbek poddanych cyklom zamrażania i odmrażania. Wyniki przeprowadzonych badań i analiz odniesiono do przedmiotowych norm i dokonano oceny przydatności stabilizowanej mieszaniny popiołowo-żużlowej do celów budownictwa drogowego.
EN
The paper presents results of investigation on stabilization of the ash–slag mixture from the landfill of “Kraków” CHP Plant using: cement, lime, Terramix F22.5 and Solitex. The research included determining basic geotechnical characteristics as well as the compressive strength without and with addition of 3, 6 and 8% of a binder after 7 and 28 days of curing samples and after 28-day cycles of freezing and thawing. The results of the conducted tests and analyses were referenced to the relevant standards and the usability of the stabilized ash–slag mixture for road engineering purposes was assessed.
PL
Charakterystyka geotechniczna mieszanin popiołowo-żużlowych z Elektrowni „Skawina” i Elektrociepłowni „Kraków”. Wpływ nasączania wodą i obciążenia na wskaźnik nośności wybranych mieszanin. Zastosowanie badanych materiałów do budowy nasypów drogowych w odniesieniu do wymogów normowych.
EN
Geotechnical characteristics of ash-slag mixtures from “Skawina” Power Station and “Kraków” Heat and Power Plant. Influence of water soaking and loading on the California Bearing Ratio of selected mixtures. Application of tested materials for the construction of road embankments in relation to standard requirements.
3
PL
Celem badań prezentowanych w niniejszej pracy było określenie wpływu metody badania na wartości granicy płynności wybranych gruntów spoistych o różnej zawartości frakcji iłowej: mało spoistego – piasku średniego ilastego, średnio spoistego na pograniczu mało spoistego – pyłu grubego oraz zwięzło spoistego – iłu pylastego. Granicę płynności oznaczano metodami: Casagrande’a, Wasiliewa i penetrometru stożkowego. Stwierdzono, że wartości granicy płynności badanych gruntów oznaczone różnymi metodami wykazały zróżnicowanie, co w istotny sposób wpływało na ocenę ich plastyczności i konsystencji. Zgodnie z normą PKN-CEN ISO/TS 17892-2:2009 granicę płynności należy oznaczać penetrometrem stożkowym, natomiast metodą alternatywną jest metodą Casagrande'a. Przeprowadzone badania wykazały, że w przypadku gruntów spoistych o zawartości frakcji iłowej do 10 – 11% różnice pomiędzy wartościami granicy płynności oznaczonej penetrometrem stożkowym lub metodą Casagrande’a były stosunkowo nieduże i wyniosły 1 – 2%, dlatego obydwie metody są prawidłowe. W przypadku gruntów spoistych o zawartości frakcji iłowej większej od 20% różnice pomiędzy wartościami granicy płynności oznaczonej penetrometrem stożkowym lub metodą Casagrande’a były nieco większe niż w poprzednim przypadku i wyniosły około 4%. W tych przypadkach oznaczenie granicy płynności można wykonać zarówno jedną jak i drugą metodą, przy czym wyżej cytowana norma preferuje metodę penetrometru stożkowego.
EN
The research presented in this paper aimed at the determination of the impact of a test method on the liquid limit of the selected cohesive soils with different content of clay fraction: loosely cohesive – clayey medium sand, moderately cohesive on the border of loosely cohesive – coarse silt and firmly cohesive – silty clay. Liquid limit was determined by the following methods: Casagrande, Vasiliev and the cone penetrometer. It was stated, that the values of the liquid limit of the tested soils determined by various method were different, which significantly affected the assessment of their plasticity and consistency. According to the standard PKN-CEN ISO/TS 17892-2:2009, the liquid limit should be determined with the cone penetrometer, whereas the alternative is Casagrande’s method. The conducted tests showed, that in the case of cohesive soils containing up to 10-11% of clay fraction, the differences between the values of the liquid limit determined with the cone penetrometer and the Casagrande’s method were relatively small and equaled 1-2%, therefore both methods are correct. In the case of cohesive soils containing more than 20% of clay fraction, differences between the values of the liquid limit determined with the cone penetrometer and the Casagrande’s method were slightly higher than in the previous case, and equaled approximately 4%. In those cases, determination of the liquid limit can be performed can be performed both using the first of the second method, though the above-cited standard recommends the cone penetrometer method.
EN
Coal combustion ash-slag mixtures have been deposited in landfills in Poland for decades. At the same time, there is a shortfall in the amount of available materials related to the construction and modernisation of transportation infrastructure. Thus, a typical landfill of a power station was chosen and the aim of the study was to assess the suitability of an ash-slag landfill mixture for construction engineering purposes. The following physicochemical analyses were conducted: pH, specific electrical conductivity and determination of the leachability of basic (Ca, Na, K and Mg) and trace elements (Cd, Pb, Cr, Zn and Cu). The content of selected basic and trace elements were determined in the eluates by FAAS and standard methods were applied for geotechnical analyses. The most likely conditions were assumed to the model. The mixture will not jeopardize surface water quality in terms of the concentrations of basic, hazardous or priority elements. The content of these elements also does not exceed permissible concentrations for groundwater. The conductance and pH of the eluates are in compliance with current laws. The solid mixture has favourable geotechnical parameters which are significantly dependent on moisture content. The slope stability calculations for embankments created from the mixture at optimum moisture content and high compaction (Is ≥ 0.95) indicate that they will be stable even in the case of high gradients (1:1.5). The slopes will be unstable in conditions of submersion, which should not occur if we assume the embankment will be used for passive flood protection
EN
High-altitude lakes, which are very sensitive ecosystems and respond rapidly to climatic changes, are one of the best targets for palaeolimnological studies. Here, we present the record of environmental changes over the last millennium that are recorded in the sediments of El Sol, a tropical, high-altitude, volcanic crater lake on the Nevado de Toluca, Central Mexico. Palaeolimnological reconstructions are based on subfossil Cladocera, diatoms, magnetic susceptibility and chemical analysis of the sediments. In general, Cladocera occurring in tropical regions, and especially at high altitude, have been studied very little. Our data indicate that in the sequence studied, the species diversity of subfossil Cladocera is very low. Only four species were recorded, and the assemblage is dominated by littoral species. Two Cladocera taxa, Alona manueli and Ilyocryptus, found at Lake El Sol are endemic. Cladocera, diatoms and the sediment chemistry show changes in Lake El Sol which are mostly related to climate. The most pronounced climatic signal was obtained for the early Little Ice Age (1350–1625 AD). This cold episode was expressed by a reduction in the frequency of zooplankton (individuals/cm2/yr) and diatoms (valves/g of dry sediment) and by changes in the organic carbon content in the sediment. Our results show that human activity was very limited throughout the study period. According to historical data the presence of humans at the lake shore was mostly occasional, usually for ceremonial and ritual purposes, and humans did not have an important influence on the lake ecosystem. Only one period was identified when human activity was important. This period corresponds to the introduction of fish into the lake at the beginning of the 20th century.
PL
Przedmiotem pracy jest mieszanina popiołowo-żużlowa pochodząca ze składowiska Elektrociepłowni Kraków (EDF Polska S.A.). Celem badań było określenie wytrzymałości na ścinanie przedmiotowej mieszaniny w aparacie bezpośredniego ścinania, w skrzynce o wymiarach w przekroju 0,1 x 0,1 i 0,12 x 0,12 m, z ramkami pośrednimi tworzącymi strefę ścinania o grubości 10 mm. Próbki formowano przy wilgotności optymalnej i wskaźniku zagęszczenia IS = 0,97, a następnie ścinano: bezpośrednio po uformowaniu, po 7-dniowej pielęgnacji próbek stabilizowanych dodatkiem 2% (wagowo) spoiw hydraulicznych (dwa rodzaje) oraz po 7-dobowej pielęgnacji próbek stabilizowanych jak wyżej i następnie nasączanych wodą przez 3 doby. Uzyskane wartości parametrów charakteryzujących wytrzymałości na ścinanie, to jest kąta tarcia wewnętrznego i spójności, były stosunkowo duże, co świadczy o dużej wytrzymałości na ścinanie badanego materiału. Nawodnienie nie wpłynęło na wartość kąta tarcia wewnętrznego, natomiast wpłynęło na zmniejszenie spójności. Wartości tych parametrów w przypadku mieszanki stabilizowanej były wyraźnie zależne od rodzaju spoiwa.
EN
The ash-slag mixture coming from the landfill of the Combined Heat and Power Plant Kraków EDF is the subject of the work. The tests aimed at the determination of the shear strength of this mixture in a direct shear apparatus, in a box with dimensions of 0.1 x 0.1 or 0.12 x 0.12 m, with intermediate frames forming 10 mm thick shear zone. The samples were moulded at the optimum moisture content and the degree of compaction IS = 0,97, and then sheared: immediately after moulding, after 7-day curing of the samples stabilised with addition of 2% (by weight) of hydraulic binders (two types) and after 7-day curing of the samples stabilised as above and then soaked in water for three days. The obtained values of the parameters characterising the shear strength, i.e. the angle of internal friction and cohesion, were relatively high, indicating a high shear strength of the tested material. Moisturising did not affect the value of the angle of internal friction, but reduced cohesion. The values of these parameters for the stabilised mixture were clearly dependent on the type of binder.
PL
Celem badań było określenie wytrzymałości na ścinanie mieszaniny popiołowożużlowej ze składowiska odpadów Elektrociepłowni Kraków (EDF Polska S.A.) oraz oporu tarcia międzyfazowego na kontakcie pomiędzy przedmiotową mieszaniną a geowłókniną PPST 100. Badania przeprowadzono w aparacie bezpośredniego ścinania. Próbki do badań formowano w skrzynce aparatu przy wilgotności optymalnej przez ich zagęszczanie do IS = 0,90 i 1,00. Ścinanie próbek przeprowadzono bez i z ich nawodnieniem. Parametry wytrzymałości na ścinanie mieszaniny popiołowo-żużlowej były duże. Stwierdzono istotny wpływ zagęszczenia, którego wzrost spowodował zwiększenie kąta tarcia wewnętrznego i spójności. Natomiast nawodnienie próbek spowodowało zmniejszenie parametrów wytrzymałości na ścinanie. Wartości parametrów oporu tarcia międzyfazowego na kontakcie mieszanina popiołowo-żużlowa a geowłóknina były również duże. Należy również wskazać, że nawodnienie próbek spowodowało zwiększenie kąta tarcia międzyfazowego i zmniejszenie adhezji. Można więc stwierdzić, że stosowanie mieszanin popiołowo-żużlowych jako kruszywa antropogenicznego jest ważnym i istotnym zagadnieniem w aspekcie ochrony naturalnych materiałów gruntowych.
EN
The tests aimed at the determination of the shear strength of the ash-slag mixture from the landfill of the Combined Heat and Power Plant „Kraków” S.A. (EDF Polska S.A.) as well as the interphase friction resistance at the contact between the mixture in question and the PPST 100 114 A. Gruchot, E. Zawisza, E. Czyż geotextile. The tests were conducted in a direct shear apparatus. Samples for the tests were formed in the apparatus box at the optimum moisture content by compacting them to IS = 0.90 and 1.00. Shearing of the samples was carried out without and with their saturation. The shear strength parameters of the ash-slag mixture were large. It was stated the significant influence of the compaction, the growth of which has resulted in an increase in the angle of internal friction and cohesion. Whereas the saturation of the samples reduced the shear strength parameters. The values of the interphase friction resistance at the contact: the ash-slag mixture and the geotextile were large as well. It should also be noted that the saturation of the samples increased the angle of interphase friction and decreased the adhesion. It can be concluded that the use of the ash-slag mixtures as anthropogenic aggregates is an important issue in terms of protection of natural soil materials.
PL
Celem pracy była ocena wpływu stabilizacji osadów dennych nagromadzonych w zbiornikach zaporowych w wyniku procesu zamulania za pomocą środków wiążących na poprawę ich właściwości geotechnicznych. Próbki osadów zostały pobrane w obszarze cofki Zbiornika Czorsztyńskiego. Osady są piaskami pylastymi o małej przepuszczalności i stosunkowo dobrym wskaźniku nośności i wytrzymałości na ścinanie. Stwierdzono doświadczalnie, że mogą one zostać wykorzystane do formowania nasypów drogowych i hydrotechnicznych. Podjęto próbę poprawy właściwości osadów przez stabilizację cementem i wapnem. Stwierdzono doświadczalnie, że stabilizacja osadów dennych za pomocą cementu i wapna znacznie polepsza ich właściwości geotechniczne, przy czym znacznie lepsze wyniki osiągnięto przy zastosowaniu cementu. Próbki z dodatkiem 12% cementu spełniły wszystkie wymagania normowe dla dolnych i górnych warstw ulepszonego podłoża. Próbki z 9% dodatkiem wapna spełniały wszystkie wymagania normowe, jednak tylko w przypadku dolnych warstw ulepszonego podłoża.
EN
Paper concerns the problem of siltation process in reservoirs (sedimentation of the river load caused by the decrease in flow velocity) and usage of the sediments. The aim of the paper was the determination of the effect on geotechnical parameters of stabilization with cement and lime the sediment in river reservoir. Samples of the sediment were taken from the backwater of Czorsztyn Reservoir (southern Poland). It is silty sand with low permeability and relatively high bearing capacity and shear strength. Based on usability evaluation of these sediments for earthworks it was stated that they can be used for embankments, both road and hydrotechnical, if some of their properties will be improved. Therefore for improving geotechnical parameters of these sediments cement and lime were used. Samples with 12% addition of cement fulfilled all the requirements concerning both bottom and top parts of the improved subgrade. Samples stabilized with 9% addition of lime fulfilled all the standard requirements concerning only the bottom layers of the improved subgrade.
EN
The objective of this study was the recognition and reconstruction of the origin of two high altitude lakes and the ecological conditions of their early existence based on subfossil Cladocera and chemical analyses. The study focused on the oldest lacustrine sediments from Lake Sol and Lake Luna, located in the crater of Volcano Nevado de Toluca (Central Mexico). The Nevado de Toluca crater developed approximately 12 ka yr BP. According to the literature, the volcano was last active approximately 3.3 ka yr BP, and the lakes developed after that eruption. The remains of nine Cladocera species were found in the bottom sediments of both lakes. The most dominant taxa were two endemic littoral species: Alona manueli and Iliocryptus nevadensis. The total frequency of Cladocera specimens in both of the sediment cores was very low. No Cladocera remains were recorded in the sediment layer at depths between 123–103 m from Lake Luna. The results of the lithological and geochemical analyses showed that this sediment layer was composed of allochthonous material, probably originating from slid down from the volcanic cone. This was suggested by the content of silica (up to 13%), iron (up to 12%), and titanium (up to 4%). The Cladocera remains recorded in the bottom sediments suggested that both reservoirs developed as freshwater lakes at the beginning of the sedimentation. The calibrated radiocarbon dates obtained for the bottom samples were 4040 to 3990 yr BP for Lake Luna (129 cm) and 4485 to 4485 yr BP for Lake Sol (89 cm). The obtained ages were older than the dates of the last eruption, which occurred approximately 3300 yr BP. This result was likely related to the type of radiocarbon dated materials (charcoals).
10
Content available Cenotes – lakes of the Yucatan Peninsula (Mexico)
EN
Cenote lakes are natural sinkholes or depressions resulting from the collapse of limestone bedrock exposing the groundwater underneath. Thousands of such lakes are particularly encountered on the Yucatan Peninsula (Mexico). These lakes were of great significance for the Maya culture as important religious places and primary source of drinking water. They permitted the survival of Mayan communities through dry periods known as “Maya drought”. Most of the cenote lakes are large open water pools measuring tens of meters in diameter. The majority of cenotes are smaller sheltered sites. Their waters are usually very clear and oligotrophic, originating from rain water filtering slowly through the ground. The authors visited and collected zooplankton samples from eight cenotes in November 2013, namely: Ik-Kil, Samula, Zaci, X-Kekn, Actum Ha, Cristal, Sian Ka’an, and Chan Chemuxil (transect Merida–Tulum– Cancun). The analysed lakes differ considerably in morphological terms, varying from very deep to shallow. Some of them are under human impact (tourists). The water samples were analysed for zooplankton content, but the phytoplankton frequently occurring was also taken into account. The obtained results are largely varied, indicated big eco- logical verity among cenotes which depended on lake age, localization and morphometry. As showed our study Cladocera zooplankton was very rare and only present at several sites. Between the fauna community Copepoda and Ostracoda species were the most abundant. Phytoplankton were present in all studied lakes and it sees that played the central role in those ecosystems.
11
Content available remote Charakterystyka geotechniczna osadów dennych Zbiornika Rzeszowskiego
PL
W pracy przedstawiono wyniki badań właściwości geotechnicznych osadów dennych Zbiornika Rzeszowskiego. Przebadano próbki osadów dennych pobranych w cofce zbiornika, powyżej i poniżej wlotu potoku Strug oraz przy stopniu. Osady sklasyfikowano jako materiał pylasty, organiczny, w stanie płynnym. Materiał uśredniony, który powstał przez zmieszanie wszystkich próbek osadów, sklasyfikowano jako pył kilkufrakcyjny, słabo przepuszczalny, o podwyższonej zawartości części organicznych oraz stosunkowo wysokich wartościach parametrów charakteryzujących wytrzymałość na ścinanie i dużej ściśliwości.
EN
The paper presents geotechnical parameters of bottom sediments from Rzeszowski Reservoir. Tested sediments samples were taken from the backwater area, below and above the Strug stream mouth and near the dam. Sediments were classified as silty organic material in a liquid state. The averaged material, which was created by mixing all the sediments samples, was classified as silt; it had a low permeability, high organic matter content, relatively high shear strength parameters and high compressibility.
EN
Stability analysis of a levee made of the bottom sediments from Czorsztyn-Niedzica Reservoir is presented in the paper. These sediments were classified as silty sands and, based on the authors’ own research, their geotechnical parameters were beneficial, so the possibility of using this material for the hydraulic embankments was considered. Stability and filtration calculations were carried out for a levee that had the same top width – 3 m, slope inclinations 1:2 and different heights: 4, 6 and 8 m. Two methods were used: analytical and numerical. Calculations were carried out without and with a steady and unsteady seepage filtration. Based on the analysis carried out it was stated that the levee made of the bottom sediments is stable even at the height of 8.0 m, although because of the seepage on the downstream side it is recommended to use a drainage at the toe of the slope.
EN
Previous researches conclude that coal mining waste and fly ashes are useful in many kind of engineering – especially in building of embankments. In fact that the embankments transfer self weight and external loads, determination of strength parameters is very crucial. The problem of well-determined shear strength parameters conducts to searching alternative investigation methods. In the aim of credible determination of strength parameters of anthropogenic soils, the half-back analysis have been proposing. The paper presents the results of two investigation method: direct shear and limit bearing capacity analysis of slope models. Results of the tests were combined together, for verification of a relationship between shear strength obtained during laboratory tests and possibility slope failure to be initiate in embankment models made of the waste materials. In consequence of the methods combination and apply of some indexing factors into analysis, a real values of the shear strength were obtained in a specific working conditions. Proposed indexing factors can be use to examine what strength parameter, determined using direct shear test, have to be modify. In the analysed waste materials incorporated into embankments treated by braking load, the shear strength parameters determined in direct shear apparatus used for stability analysis, did not confirm stability failure phenomena what has occurred. Investigation of shear strength parameters of coarse minestone waste material in direct shear box apparatus overstate in significant way the value of cohesion. In case of fine size fly ash, the direct shear box test overstate the value of friction angle. It has to be postulated in attention of earth structure safety exploitation, the strength parameters of anthropogenic soils should be determine in real work conditions. If it is not possible, the laboratory tested strength parameters should by modify using tests simulating real work condition of the structure. A testing method used for obtaining the shear strength parameters of coarse and fine size granular waste material, strong interacting on the boundary conditions in test. Shear strength parameters of the tested waste materials are strong associated with the loading path. In consequence, is very crucial what are the work and test conditions of the material.
PL
Praca zwiera wyniki badań mrozoodporności oraz wpływu temperatur ujemnych na zmiany parametrów geotechnicznych żużla wielkopiecowego o uziarnieniu 0÷63 mm, pochodzącego ze składowiska „Pleszów” w Krakowie. Zakres badań obejmował oznaczenie uziarnienia oraz parametrów charakteryzujących zagęszczalność (wilgotność optymalna i maksymalna gęstość objętościowa szkieletu), wytrzymałość na ścinanie (kąt tarcia wewnętrznego i spójność) oraz wodoprzepuszczalności (współczynnik filtracji). Badania przeprowadzono na materiale wyjściowym oraz poddanym 15 cyklom mrożenia i rozmrażania. Analizę wyników badań przeprowadzono w aspekcie oceny przydatności przedmiotowego żużla do celów budownictwa ziemnego, w szczególności drogowego.
EN
This paper presents the test results of freeze resistance as well as the impact of sub-zero temperatures on the geotechnical parameters of blast furnace slag with graining-size distribution 0-63 mm from ”Pleszow” storage yard in Krakow. The scope of research include marking of the graining and parameters for compactibility (optimal humidity, inner humidity and coherence), shear strength (internal friction angle and coherence) as well as water-permeability (filtration coefficient). The tests were performed on stock and then 15 cycles of freezing and defrosting. The results analysis was performed in respect of suitability assessment of the slag for the purposes of ground construction, particularly road construction.
PL
Artykuł zawiera wyniki badań wytrzymałości na ścinanie odpadów powęglowych z KWK Rydułtowy-Anna, popiołów lotnych z Elektrowni Skawina oraz mieszanek odpadów powęglowych z 10, 20 i 30%(wag.) dodatkiem popiołu. Do badań zastosowano aparat standardowy bezpośredniego ścinania (popiół lotny) oraz aparat średniowymiarowy (odpady powęglowe oraz mieszanki odpadów z popiołem). Badania wykonano na próbkach o wilgotności optymalnej i wskaźniku zagęszczenia Is = 0,95, nawodnionych przed ścinaniem. W analizie wyników uwzględniono wcześniejsze badania na tych samych materiałach lecz nienawodnionych. Stwierdzono, że parametry wytrzymałościowe badanych materiałów były stosunkowo duże, zależne od warunków wodnych, a w przypadku mieszanek również od dodatku popiołu.
EN
The paper presents the results of tests of the shear strength of coal mining wastes from Rydułtowy-Anna mine, fly ash from the Power Station Skawina and mixtures of the coal mining wastes with 10, 20 and 30% additive of fly ashes. The standard direct shear apparatus with box (for fly ash) and medium size apparatus with box (coal mining wastes and mixtures of coal mining wastes with fly ash) were used for the tests. The investigations were conducted on the samples of the optimum moisture content and compaction index Is = 0,95, saturated before shearing. The results analysis took into account the earlier tests on the same materials but non-saturated. It was stated, that the strength parameters of the tested materials were relatively high, depending on the water conditions, and in the case of the mixtures also on the ash content.
EN
A new unusual morphotype of Acroperus harpae (Baird, 1834) was found in Lake Mỳvatn and its neighbouring Lake Budlungaflói in Iceland. This form, A. harpae f. multidentata is characterized by a very large head keel and by 5-9 denticles on the posterovental angle of the valves instead of 1-3 common for A. harpae. The new form did not differ from typical A. harpae in the morphology of the postabdomen, head pores or any appendages. A study of Lake Mỳvatn sediments reveled that this form existed in the lake for at least two thousand years.
EN
This paper focuses on the usefulness of a palaeolimnological method called the joint algological and zoological analysis. The joint algo-zoological analysis involves counting all identifiable remains of the main algae groups (Bacillario- phyta, Cyanophyta, Desmidiales, other Chlorophyta, Trachelomonas sp.) and invertebrate groups (Cladocera, Ostra- coda, Chironomidae, Chaoborus sp., and other insects, Turbellaria, Bryozoa, Spongia and Testacida) in volumetric samples. We present results from recent sediments of Lake Glubokoe (Moscow region, Russia) as an example of the application of this method. We reconstruct the structure of phytoplankton, zooplankton and zoobenthos communities and their dynamics over the last 25 years. Our results support the validity of this method in the reconstruction of the structure of phyto- and zooplankton communities and their dynamics, information that may be lost when carrying out separate analyses for individual groups. Simplicity is another advantage of this methodology.
EN
We present the last 500 years of history of a high-altitude tropical lake Lago de la Luna located at Nevado de Toluca crater, Central Mexico, based on subfossil Cladocera analysis. Through the studied sedimentary sequence only five Cladocera species were present. Cladocera community was dominated by littoral species (4) and among them one (Ilyocryptus nevadensis) is endemic. The detailed analysis of the sediments (every 1 cm) allowed us to track contemporary climatic and anthropogenic changes. Our results showed that Lago de la Luna is a very sensitive ecosystem and has strong response to climatic changes. The most remarkable change in the Cladocera community was observed between 1683-1780 yr, which was well correlated with the Little Ice Age. PCA results implied that modern state of the lake Lago de la Luna is very similar to one 400-500 yr ago. Only one period was identified when human impact was of importance. This period seemed to correlate with changes in the lake ecosystem due to fish introduction in the 1950s.
19
Content available remote Wytrzymałość na ścinanie mieszanek odpadów powęglowych z popiołami lotnymi
PL
Celem pracy było określenie wartości parametrów charakteryzujących wytrzymałość na ścinanie nieprzepalonych odpadów powęglowych (d < 63 mm) pochodzących z kopalni "Rydułtowy-Anna", popiołu lotnego z Elektrowni Skawina oraz mieszanek odpadów powęglowych z 10, 20 i 30 % dodatkiem popiołu. Na podstawie przeprowadzonych badań określono wpływ zagęszczenia oraz dodatku popiołu na zmiany kąta tarcia wewnętrznego i spójności. Stwierdzono, że parametry wytrzymałościowe badanych materiałów były stosunkowo duże, a w przypadku mieszanek wykazywały zależność od dodatku popiołu. Dokonano również oceny przydatności badanych materiałów w budownictwie ziemnym, jako alternatywy dla naturalnych gruntów mineralnych.
EN
The work aimed at the determination of values of parameters characterising the shear strength of unburnt coal mining wastes (d < 63 mm) from the "Rydułtowy-Anna" mine, fly ash from the Power Station Skawina and mixtures of coal mining wastes with 10, 20, and 30 % (by weight) additive of fly ash. On the basis of investigations carried out the influence of condensation and ash additive on the changes of the angle of internal friction and cohesion were determined. It has been stated that the strength parameters of the tested materials were relatively high, and in the case of mixtures they have pointed out the dependence on ash additive. Moreover, the assessment of usability of the tested materials for earth structures as an alternative for natural mineral soils was performed.
PL
Celem pracy było określenie parametrów ściśliwości, to jest wartości osiadań, modułów ściśliwości pierwotnej i wtórnej odpadów powęglowych z kopalni „Rydułtowy-Anna” oraz ich mieszanek z 10, 20 i 30 % dodatkiem (wagowo) popiołów lotnych z Elektrowni Skawina. W wyniku badań stwierdzono, że najmniej ściśliwa była mieszanka odpadów powęglowych z 10 % dodatkiem popiołu, bardziej ściśliwa była mieszanka odpadów powęglowych z 20 % dodatkiem popiołu i same odpady powęglowe, a największą ściśliwość wykazała mieszanka odpadów powęglowych z 30 % dodatkiem popiołu. Odpady powęglowe oraz mieszanki odpadów powęglowych z popiołem wykazują ogólnie niezbyt dużą ściśliwość oraz dużą wytrzymałość na ścinanie. Można więc stwierdzić, że materiały te mogą być wykorzystane w budownictwie ziemnym oraz w innych dziedzinach inżynierii lądowej i wodnej.
EN
Determination of parameters of compressibility, that is the values of settlement as well as primary and secondary compressibility moduli of coal mining wastes from the Rydułtowy-Anna mine and their mixtures with 10, 20 and 30 % (by weight) additives of fly ashes from the Power Plant Skawina was the purpose of this work. The results of the study have shown that the mixture of coal mining wastes with 10 % additive of ash was the least compressible. More compressible were: mixtures of coal mining wastes with 20 % additive of ash and coal mining wastes alone. The most compressible was the mixture of coal mining wastes with 30 % additive of ash. In general, coal mining wastes and their mixtures with ash are characterized by low compressibility and significant shear strength. Thus, the results of the tests show, that these materials can be used on a broad scale in earth structures and other fields of civil engineering.
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