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Analiza sedymentologiczna drobnoziarnistych osadów górnoordowicko-dolnosylurskich basenu podlasko-lubelskiego

Lis J.

Przegląd Geologiczny

2010

Vol. 58, nr 3

259-262

In western and central parts of the Podlasie-Lublin Basin, Upper Ordovician-Lower Silurian mixed siliciclastic-carbonate section is dominated by fine-grained sediments (claystones, mudstones), which are passing into more carbonaceous ones towards the east. In this region, subsidence was controlled by flexural bending of the East European Craton margin. Sedimentological analysis of drill cores revealed that deposition of those fine-grained sediments originated from suspension and traction currents. Amount of oxygen plays important role in the rock record (Fig. 1) whereas occurrence of pyrite is significant for determinations of sedimentary conditionsion, also in terms of sea level changes (Fig. 2). The rocks display abundant sedimentological structures such as current ripples, wave ripples, hummocky cross-stratification (HCS), graded beds, water escape structures, soft sediment deformation and scours (Fig. 3). The rocks are also characterized by predominance of wave ripples, common scours, graded beds and soft sediment deformations whereas current ripples, water escape structures and HCS are rather rare. The most frequent of the ichnofacies elements include unlined, rarely branched Planolites, which represent Scolithos, Cruziana and Zoophycus ichnofacies. The size of elements of Planolites ichnofacies appears dependent on environmental conditions and ranges from 0.5 mm to 15 mm. Chondrites, Anconichnus, Helminthopsis and Teichichnus, very important environment indicators, are present but not that common (Fig. 4). Textural analyses along with the records of diagenetic features made it possible to distinguish a succession of stratigraphic parasequences (Fig. 5). Early carbonate cementation appeared important, especially in the case of suble or invisible changes in grain size. On the basis of the obtained results, depositional environment of fined-grained sediments in the Podlasie-Lublin Basin was interpreted as a wave-dominated shelf with turbidite episodes. Detailed sedimentological observations are crucial for definiting facies types and prediction of their distribution, but also for tracing the most organic-rich units in the sedimentological profile, as the basic in terms of gas shale prospects. Apparently monotonous fine-grained sediments (claystones and mudstones) are shown to be in fact miscellaneous.

Komputerowe ujęcie wyznaczania nośności mostów kolejowych

Machelski C.

Prace Instytutu Badawczego Dróg i Mostów

1998

nr 3-4

5-43

W celu ujednolicenia oceny nośności wszystkich, eksploatowanych mostów (starych i nowych) utworzono pakiet programów NOSSMOK, przygotowany do wprowadzenia w systemie zarządzania mostami kolejowymi SMOK. W NOSSMOK przygotowano cztery poziomy oceny nośności elementów mostów, w zależności od zakresu szczegółowych informacji o obiekcie. Na najniższym poziomie - analizy parametrycznej - podawane są jedynie dane ogólne o obiekcie, wziete np. z karty ewidencji mostu. Na poziomie analizy podstawowej uwzględnia się informacje o stanie technicznym elementów, dotyczące zmian wyposażenia oraz stopień uszkodzeń materiału. W przypadku wyboru analizy szczegółowej, wykonuje się pełne obliczenia elementów z uwzględnieniem ich aktualnego stanu. Ostatni, czwarty poziom obliczeń dotyczy analizy dynamicznej i stateczności oraz symulacji awaryjnej pracy elementów mostów (obliczenia sprawdzające). Jako podstawę oceny nośności mostów przyjmuje się aktualne normy projektowania. W przypadku obiektów starych, zaprojektowanych według innych ni? obecne wytyczne konstruowania mostów, dostępne informacje o konstrukcji przetwarzane są w NOSSOMOK na dane stosowane w projektowaniu nowych mostów. Metodyka pracy nośności mostów kolejowych może być także wykorzystana do oceny nośności mostów drogowych.

At the aim of unification of the assessment of all bridges inder operation (old and new ones) a package of programs NOSSOMOK was established. It has been prepared for introdicing it at the management system for railway bridges SMOK. At NOSSMOK, in dependence of scope of detailed information about bridge structure, four levels of bridge elements bearing capacity assessment has been formulated. At the lowest level - dealing with parametrical analysis - only bridge structure general data are given, taken e. g. from the bridge evidence chart. At the level of basic analysis information dealing with the element technical condition, concerning equipment changes as well as rate of material deterioration are taken into consideration. In case of choose of detailed analysis, full calculations of elements with consideration of their actual condition are done. The last, fouth level of calculation deals with dynamic and stability analysis as well as the critical situation of bridge elements behaviour (veriffication calculations). As a basis for bridge bearing capacity assessment the actual design standards are taken into account. For old bridge structures, designed under others as present directives for structural design of bridges, accessible information on the structure are transformed at NOSSMOK on the data applied at the designing of new bridges. Methodology of railway bridges bearing capacity assessment can be also applied for the assessment of road bridges bearing capacity.