Characterization and mechanical properties of the Eocene Buda Marl

Abstract The mechanical behavior of the Buda Marl lies between those of rock and soil; it is therefore appropriate to define it as both weak rock and strong soil: some marl types behave like a weak rock and others like soil. In such cases the strength parameters of the material can be determined by rock mechanical or soil mechanical laboratory investigations. Often a problem occurs when the material cannot be assigned to either of these classes, in which case neither the commonly-used rock mechanical nor the soil mechanical tools are applicable to define the strength properties of the material. In this case the mechanical parameters of the material can only be estimated in an empirical fashion. The goal of this paper is to demonstrate the rock mechanical properties of the marl, using an empirical method, which can be use to determine the physical properties of a material that is neither rock nor soil

Engineering geologic properties of the Oligocene Kiscell Clay

Abstract The Kiscell Clay is the most frequently-occurring rock type of Budapest, especially on the Buda side of the Danube. It occurs near the surface as well as at great depth; for the purposes of this study the upper, approximately 35 meters of the unit was investigated. The results of previous laboratory analyses were collected and more than 2000 test results evaluated. Physical properties such as plasticity index, density, void ratio, and coefficient of compressibility were tested and the results statistically analyzed. Correlation between different properties is shown in graphic form, and equations are proposed to describe the various coefficients

The Effect of GSI and mi on the Stability of 3D Twin Tunnel in Limestone

The Generalised Hoek-Brown (GHB) failure criterion is one of the most used criteria to study the behaviour of the rocks; affected parameters of the Hoek-Brown equation are Geological Strength Index (GSI), intact rock constant (mi), and Disturbance factor (D). GSI is one of the rock classification systems used to evaluate jointed rocks. In light of this equation, this paper studies the stability of unsupported twin tunnels in a weak rock by changing the mentioned parameters (GSI, mi) to find the relation between the stability and these parameters under different distances between the centres of the tunnels (L). The tunnels have a circular cross-section with a diameter (B), and they have been modelled in three dimensions using Rocscience software package (RS3). The results showed that the stability of the tunnels, which was represented by the strength reduction factor (SRF), increased as a result of increasing L/B or GSI in the studied range; for mi , the modelling results showed that the SRF value increased while mi value was increased

Numerical Testing of a Small-Scale Stone Masonry Arch

This paper presents the required preparatory investigations for the construction of a masonry vault model experiment under laboratory conditions. The analyzed factors included structural design, material, loading and geometry of the model. A numerical modelling was made by Phase2 finite element program to check the performance of the masonry vault and the failure criteria.The results show that the connections of the masonry elements have considerable influence on the behaviour of small scale vaults. Thus the eect of the tensile strength of the connections was analysed in particular. The paper presents the different failure mechanisms and behaviours of continuum shells and masonry shells. Additionally, the behaviour of the partly cracked connections has been analysed.

Engineering geologic evaluation of overcompacted claystone, new metro line, Budapest

Abstract The Oligocene clay units in the Budapest area along the new metro (subway) line show different properties than most others. They are denser and of greater strength than most of the unconsolidated ones. This paper provides an overview of their engineering geologic properties using nearly 4700 physical parameter data. These data were obtained from cores representing sampling intervals of the Kiscell Clay, on the Buda side of the Danube River. Seventeen engineering geologic parameters were used in the description of the clay. The parameter analyses show that the clay behaves as a soft rock rather than a soil

Egyetemek hallgatói megtartóképessége = Universities’ student attraction

Tanulmányunkban egy, a szegedi közgazdászképzésben részt vevő 30 hallgatóval végzett mélyinterjús vizsgálat eredményeit mutatjuk be, ahol azt vizsgáljuk, hogy mesterszakon való továbbtanulásuk helyszínének választását – Budapest versus vidék – mi befolyásolja. Legfőbb megállapításunk az, hogy a hallgatók elsősorban nem az intézményt, hanem Budapestet választják a vidékkel szemben. Választásukban fontos szerepe az elérhető életminőségnek (fizetés, kikapcsolódási lehetőségek stb.), a párválasztásnak, a családból való kiszakadásnak, illetve annak van, hogy valaki dolgozott-e alapszakos tanulmányai mellett vagy sem. = In our study, the preliminary results of our qualitative research involving 30 Hungarian university students are demonstrated. The research examines the factors which influence bachelor students when they choose the place of their master studies: whether it is the capital city or the countryside in Hungary. The main conclusion is that when students choose a higher educational institute in Budapest instead of the countryside, they primarily choose Budapest for its being the capital city and not because of the particular higher education institution in the city. The attainable life quality (salary, recreation possibilities, etc.), mate selection, the wish to become independent from the family, and work experience gained during the undergraduate studies play a key role in their decision

Laboratory determination of direct shear strength of granitoid rocks; examples from the host rock of the nuclear waste storage facility of Bátaapáti (Hungary)

Abstract This paper provides test results and interpretation of the shear strength of granitic rocks. The samples were obtained from Bátaapáti (South Hungary), where the low and medium-activity nuclear waste storage facility of Hungary is under construction. The experiments were carried out under laboratory conditions by using direct shear strength tests of samples drilled and cut from larger granitic blocks. The friction angles of both the maximal and residual shear stress, as well as the cohesion, were detected for various joint systems and also for the cut surface of the granitic rock. The interpretation of test results includes the evaluation of normal stress versus shear strength for cut, moderately rough, rough and calcite-filled joints. The tests have demonstrated that the average internal angle of friction for granitic rocks exceeds 20°, with a maximum of 39° for rough surfaces. Calcite-filled joints have lower friction angles, in the range of 16–23°. The peak shear strength of granitic test specimens was between 0.8 and 4.1 MPa, depending on the surface and joint fill