Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 6

Liczba wyników na stronie
first rewind previous Strona / 1 next fast forward last
Wyniki wyszukiwania
help Sortuj według:

help Ogranicz wyniki do:
first rewind previous Strona / 1 next fast forward last
EN
This paper highlights the application of shallow non-invasive geophysics (electrical resistivity tomography) supported by sedimentological analysis applied to the investigation, description and interpretation of Upper Jurassic limestones exposed in the abandoned quarry near the village of Tomaszowice (Kraków Upland, southern Poland). Within this site, on the northern margin of the Krzeszowice Graben, a facies diversity of Upper Jurassic limestones can be observed. Field exposures were analysed to broadly characterize these Upper Jurassic limestones in terms of facies and microfacies development. Three facies types, including pelitic limestones, bedded limestones and carbonate gravity-flow deposits, composed of numerous microfacies, have been distinguished. ERT study using a dipole-dipole array has been carried out, along 5 parallel 110 m long profiles and along a perpendicular 110 m long profile, north of the Tomaszowice Quarry wall. The use of ERT in combination with the geological data allowed characterization and description of the geology at the research site as well as the determination of the lithological composition and internal architecture of the subsurface. Furthermore, the ERT interpretation results indicated the presence of a series of a secondary faults closely linked with the Krzeszowice Graben. The distribution of the gravity-flow deposits reflects the fault zone pattern of the graben and Late Jurassic fault activity.
PL
W publikacji przedstawiono przypadek znaczącej deformacji terenu wywołanej podziemną eksploatacją górniczą, który nie znajduje wytłumaczenia w standardowym modelu zachowania się górotworu. Przyczynę powstania tak silnie destrukcyjnych deformacji należy upatrywać w występującej lokalnie specyficznej budowie geologicznej. Deformacje stwierdzone zostały pomiarami geodezyjnymi prowadzonymi na fragmencie sieci obserwacyjnej zlokalizowanej nad polem górniczym. Powiązanie powstałych na powierzchni terenu deformacji z budową geologiczną możliwe było dopiero po przeprowadzeniu szczegółowych badań geofizycznych. Wyniki zarówno pomiarów geodezyjnych, jak i geofizycznych zostały zaprezentowane i opisane w artykule.
EN
This publication presents the case of land deformations with a strong, destructive impact which cannot be explained based on standard, model behaviour of the rock mass, and the land surface under the conditions of the impact of the underground mining exploitation. The reason for this type of deformation in the case described should be sought in a special geological structure which occurs locally. The deformations were found with the use of geodetic surveys, conducted in the section of the observation network located over the mining field. It was possible to connect the deformations on the land surface with the geological structure only after the detailed geophysical research had been conducted. The results of both the geodetic and geophysical measurements are presented and described in this publication.
EN
DC resistivity methods, soundings and Electrical Resistivity Tomography, were applied to study shallow geology in the place of planned construction of an experimental flood bank. The geoelectrical surveys provided quantitative information about the spatial presence of the various geoelectrical/geological layers: alluvial soils, sands, gravels and clays. ERT allowed maps to be constructed showing subsurface structure. A combination of geoelectrical and geological information resulted in a much better identification of the geological structure.
PL
Zapadanie skrzydła południowo-zachodniego kapelanii przy kościele św. Józefa S.S. Bernardynek postępuje od 2010 roku, powodując pękanie murów okalających ogród, a zwłaszcza pomieszczeń piwnicznych pod zabudowaniami przykościelnymi. Celem badań jest określenie właściwości i stratygrafii gruntów w podłożu zagrożonego obiektu, jak i w najbliższym jego sąsiedztwie. Archeologiczne źródła i ich międzydziedzinowa interpretacja w kontekście wykonanych profili geologicznych, w oparciu o odwierty i wąskoprzestrzenne odkrywki, wykazały złożony układ nawarstwień historycznych i ich potencjalne oddziaływanie na budowle. Oprócz odwiertów i badań gruntoznawczych przeprowadzono georadarowe i elektrooporowe rozpoznanie ośrodka pod poziomem piwnic oraz badania geochemiczne próbek gruntu. Wyznaczony poziom calca jednoznacznie wskazuje na położenie zagrożonych obiektów w strefie 30 stopniowego skłonu pierwotnej morfologii terenu, w którego dnie znajdują się podatne na upłynnienie namuły. W stratygrafii wyróżniono także obecność znacznej miąższości, nierównomiernie zalegającej warstwy organicznej o dużej ściśliwości i małej nośności, stanowiącej materię wybitnie niebudowlaną. Na mechanikę budowli mają wpływ zróżnicowane pod względem stateczności utwory, ale także obecność sztywnych, historycznych obiektów fundamentowych. Istnienie tego typu czynników uzewnętrzniło się w postaci pęknięć murów w rejonie budowli klasztoru, a także zaburzenia poziomu podłóg szczególnie widoczne w piwnicach kapelanii. Obserwowane rozluźnienie struktury podłoża, o zasięgu większym niż teren klasztoru SS. Bernardynek, związane jest prawdopodobnie z szeregiem odwodnień głębokich wykopów wykonywanych w związku z wieloma realizowanymi inwestycjami w gęsto zabudowanej, zabytkowej części Starego Krakowa. Rozwój nowoczesnego miasta w sieci nawarstwień historycznych wymaga stałego monitorowania warunków wodnogruntowych podłoża. Zarówno nadmierny drenaż, jaki i zbytnia retencja wód zaburza stateczność zabytkowych budowli i grozi katastrofą budowlaną.
EN
The collapsing of the south-east wing of Kapelania at the Św. Józef Church of the Bernardine Convent started in 2010, causing fracturing of the walls around the garden, and especially the cellar rooms under the buildings near the Church. The aim of research is to determine the properties and stratigraphy of the earth in the subsoil of the endangered object, as well as of its immediate neighbourhood. Archaeological sources and their interdisciplinary interpretation in the context of the geological profiles conducted, based on the auger holes and narrow open pits, attest to a complex set of historical layers and their potential effect on the buildings. Apart from auger holes and ground-researching investigations, there were GPR and electrical resistance tests of the matter below the cellars level as well as geochemical tests of the earth samples. The established level of undisturbed subsoil clearly shows that the endangered buildings are situated within the 30% slope of the original terrain, in which bottom level there are muds which easily change texture into fluid. In the stratigraphy, there was also established an organic layer of substantial thickness, which is completely unsuitable for construction. The mechanics of the building is affected by deposits of varied stability and also by the presence of rigid objects connected with historical foundations. The existence of these factors manifested itself in the form of wall fractures in the area of convent, especially visible in kapelania, causing also disturbance of the floor level in the kapelania cellars. The observed loosening of the subsoil structure, possibly with a range greater than the area of the Bernardine Convent, is connected with a series of drainage works of deep excavations, in connection with a number of realized investments in the densely populated, historic part of Old Krakow. The development of the modern town within the net of historical layers demands constant monitoring of water and earth conditions of the subsoil. Both excessive drainage and water retention damage the stability of historical buildings and bring the threat of construction disaster.
EN
The Electrical Resistivity Tomography (ERT) method was applied at the SW foot of the Wawel Hill was applied. The survey was carried out along five survey lines (P1-P5), 50 m long each. The Wenner alpha array with spacing a = 0.5 m, 1.0 m, 1.5 m, 2.0 m, 2.5 m, 4.0 m, 5.5 m, 7.5 m, and 10.0 m was used. The basic electrode spacing was 0.5 m. In apparent resistivity contours and sections we can distinguish two zones, which have noticeably different resistivity values. The low resistivity zone dominates in the deeper part of the section on all survey lines, especially on the profiles located in the close neighbourhood of the Vistula River. The relative high resistivity zone is probably the effect of complex local geology, as well as the influence of the limestone of the Wawel Hill. Based on ERT inversion results, three resistivity zones were distinguished. Then the probable lithological or/and anthropogenic character was assigned to them. The shallowest zone has the thickness of about 0.5 m and results probably from accumulation of weathered limestone fragments derived from the Wawel Hill. It may be that high resistivity zones have anthropogenic character. Below, a zone of water-bearing sands was recorded, which may result from redevelopment and reclamation of this area. Thickness of this zone increases towards the Vistula River. Another zone, which can be identified with limestone, was identified on survey lines P4 and P5. This could also be result of accumulation of the calcareous debris for the purpose of planation of the area. In order to generalize and simplify the characterization of the quaternary sediments, ID interpretation was made. The method allows us to estimate the depth of groundwater, which in that place is about 5 m.
EN
Single Electrical Resistivity Tomography (ERT) survey was carried out in the Manor and Park Complex in Nowa Huta (Krakow Branice, Poland). It was applied at a small distance and parallel to the longer wall of a monumental building containing an empty 3 m deep basement. Analogue modelling was performed in order to recreate the field study at the proper scale. The laboratory set-up consisted of a water tank where electrodes were mounted to the particular plate, which rested on water surface. The basement model was made out of a non-conducting material. The default and robust inversions were tested and these variants were also considered with the use of numerical modelling. Laboratory experiments have confirmed that zones visible in the interpreted field section are caused by the influence of the building cellar located next to the survey line. Zones of this kind are additionally disturbed by the local geological structure. The experiment has pointed out, among others, that as the distance between the survey line and the underground body increases, the inversion results are still burdened by an object influence. Thus, similar situations can be verified with the use of analogue modelling presented in this paper or 3D numerical one.
first rewind previous Strona / 1 next fast forward last
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.