Péter Görög

Stability Analysis of Wine Cellars Cut into Volcanic Tuffs in Northern Hungary

There are more than 570 underground wine cellars that were constructed from the 13th century in the city centre of a town (Miskolc) in NE Hungary. With the recent rapid urban development and the population growth many of the cellars are endangered and there is a risk of collapse and structural damage. The present paper focuses on the stability analyses of the slope with the cellars by using various data sets including field surveys, core drillings, laboratory analyses and slope stability modelling by Phase2, a finite element modelling software. The cellars are found in three levels within a vertical elevation of more than 80 m. The prevailing lithology is a Miocene andesite tuff with a thickness of 50–60 m. Besides andesite tuff 0.7–1 m-thick layers of sandstone, 0.2–0.5 m of clay and very thin 0.2–0.3 m of bentonite also occur. The sequence also contains a thin bed of rhyolite tuff. The andesite tuff is heterogeneous but it is considered as a typical bimrock with signs of redeposition. For understanding the geology 4 core drillings were made. Cylindrical tests specimens of cores were used for rock mechanical analyses. Laboratory tests included uniaxial compressive strength tests, indirect tensile strength tests and triaxial strength tests. The data set obtained from laboratory analyses and measured joints were used as input parameters for the 2D modelling by Phase2 software.

Landside Problem and Its Investigations in Miskolc (Hungary)

The importance of Cultural Heritage has emerged since the early 1970s, including cultural, natural and mixed properties. Hungary is also one of those countries having great properties of importance such as historical castles, settlements, wine cellars. Northern Hungary has good advantage to develop man-made structures such as wine-cellars. The developments of wine cellars in Northern-Hungary were due to the suitable geological conditions, the social and the economical expectations in the 15th or 16th century. Recent rapid urban development and the population growth is causing damages within the infrastructures both on and under the surface that emerges geotechnical and engineering geological solution. In the city centre of Miskolc (Hungary) can be found the Avas hill, which contains more than 530 underground wine cellars and a church registered as a cultural heritage built in the 13th century. The hill is composed of late Badenian—mid Sarmatian (13.7–12.5 million years) acid dust tuff, variably bentonitic rhyolite tuff, and re-worked sandstone, intercalated placer and extraclastic andesite tuff. This article aims to reveal the cultural importance of the Avashill where reconstruction works should take place. The geological framework of the area significantly aggravates the stability problems, which is due to the heterogeneous geological strata. Identifying each layers in geotechnical aspects a ‘bimrock’ type of rock was found within the strata. Matrix and block contrast of the bimrock can define the behavior of this type of rock either under the surface or in outcrops. Our aims, to determine its rock mass and geotechnical classification and identify each bimrocks according to their matrix content as well as investigate its role within the geological strata. The heterogeneity of the hill reveals the question whether the poor geological characteristic of the rocks mainly determine the stability of the hill.

Significance of Joint Pattern on Modelling of a Drill and Blast Tunnel in Crystalline Rock

The first underground radioactive waste repository for low and intermediate level waste in Hungary is being built in the outskirts of the village of Bataapati. The total length of tunnels driven to date is over 5,200 m including two inclined access tunnels, the base tunnels and the first two emplacement chambers. The tunnels were driven in fractured granitic rocks. Based on the discontinuities the host rock of the repository can be considered as an assembly of blocks, therefore the discrete element modelling approach can be used to provide representative results of its behaviour. A hybrid continuum-discrete model is presented, where the near-field is modelled as a blocky rock mass, and the far-field is modelled as a continuum using the built in deformable blocks of the 3DEC software. Convergence monitoring was carried out in the modelled section that offers the ability to check the validity of analysis results. This paper focuses on the effect of joint pattern on the prediction capability of the discrete model. Different possible representations of the measured joint pattern were examined to assess the effect of joint pattern on the results, particularly on internal forces in rock support.

Dimension stones of the North Hungarian masonry arch bridges

Stone masonry arch bridges in North Hungary represent cultural heritage values. For the maintenance and preservation of these bridges detailed mapping of lithologies and weathering forms are required. The purpose of this paper is to present the identified lithotypes, their conditions (weathering grade) and their petrophysical properties by using in situ lithological mapping, documentation of weathering forms, non-destructive tests and laboratory analyses. Furthermore these analyses demonstrate the difficulties of characterization and diagnostics of the historical construction materials. Additionally the results of condition assessments and the properties of the four different dimension stones from four different sites provide examples for the large dissimilarities regarding the strength parameters. The above-listed parameters are required as input data for stability calculations and modeling of these structures.

Effect of different conservation methods on some mechanical properties of swine bone

In the development of new strategies for different spine fixation methods, new methods must be tested biomechanically under in vitro conditions before clinical trials can be performed. The effect of different conservation mode on the mechanical properties of vertebrae is an important question. The aim of our research was to determine the effects of three different conservation methods (fresh, no conservation – F; fresh-frozen – FF, alcohol-glycerin-fixation – AG; cooling-storage – CS). 100 swine vertebrae (Th4-Th8) were dimidiated into two specimens. These 200 specimens were assigned to four different groups. After conservation, the Young modulus and compressive strength were determined and compared to the same properties of fresh specimens. After 48-hour cooling the Young modulus and the compressive strength decreased by 39%. After 27-day freezing the Young modulus and the compressive strength decreased by 5%. After 27-day storage in ethyl-alcohol the Young modulus decreased by 12% and the compressive strength increased by 57%. The different conservation methods significantly influenced the mechanical properties of swine vertebrae. Mechanical properties were influenced less by frozen storage, so this type of storage is recommended for the conservation of vertebrae.