Rock Slopes as Engineering Constructions

The civil engineer and the geologist are very much concerned with rock slopes because they may be called upon to build and maintain safe, economical and useful structures even on hasardous ground. Such a task requires not only proficiency and a thorough understanding of the factors involved, but also intuition and experience. It should not be thought, however, that there is always a feasible solution or if there is one it should be pushed through at all cost

Foundation and Solidity Survey of the Monument Trianon Cross on the Ság Hill

In connection with the landscape architecture of the abandoned basalt quarry on the Ság hill, it was necessary to check the solidity and foundation conditions of the monument standing there. The report expounds the results of the survey and makes proposals concerning the necessary tasks

Testing of Hungarian aggregates for railway ballast according to MSZ EN 13450: 2003

Abstract In June 2003 Hungary accepted the European Standard for Aggregates for Railway Ballast (MSZ EN 13450: 2003). The European norm, compared with the Hungarian Standard, also includes a new examination method called the micro-Deval method for railway ballast aggregates, which was previously not used in Hungary. This paper presents the test results of aggregates for railway ballast-producing quarries, according to newly accepted Standard. The test materials consist of andesite, basalt, dolomite and limestone. The results cover a significant range. The study was aimed at finding a relation between the testing methods, in order to reduce the testing procedure; however, no clear relationship was found

River - Groundwater Interaction over the Region of INFOPARK-Budapest

The region around the former Kopaszi-sandbank, a shallow, degraded part of the river Danube is now a dynamically developing district of the capital with a campus and the so-called INFOPARK. As the area itself was filled with various type of material during the last century, due to the prescription of the environmental authority regular control of the water quality parameters is introduced. Several groups of observation well were set to for the monthly observation of water quality parameters and the groundwater levels, as well. These levels are influenced by natural processes like the regime of the river or the precipitation, and by the buildings with foundations reaching the aquifer. The aim of this study is to show the interaction between the river and groundwater levels with special respect to the effects of buildings with deep foundations

HOW DOES THE WATER SATURATION INFLUENCE THE MECHANICAL PROPERTIES OF THE VOLCANIC TUFFS?

Different Hungarian volcanic tuffs (andesite tuffs, basalt tuffs and rhyolite tuffs) were investigated with the goal to determine the influence of the water content on their strength. The following petrophysical constants were measured for all the samples both in dry and saturated conditions: bulk density, ultrasonic wave velocity, uniaxial compressive strength (UCS) and Young´s modulus. The destruction work (strain energy) was calculated from the measured stress-strain curves, as well. The influence of the water for the UCS, impedance (scalar of the density and the ultrasonic wave velocity) and the destruction work is shown. In these cases linear relationship can be written between the dry and the saturated constants. Both linear and power equations can be used for the effect of the water on Young´s modulus. Finally the UCS is written as the function of the density and the impedance

Quality measuring numbers of milled edges of granite surfaces

Automated machining of various stone made products such as tiles, statues, machine tool and measuring machine beds are expanding and evolving. In case of stone milling processes arises a problem which is that right now there is no objective and generally usable measuring system which would define the characteristics of milled edge chipping. In this paper a qualifying model is introduced that could define the maximal chipping depth and average chipping measure of milled edges of granite products. While the second part of this publication will depict the process of investigation. Volume reduction of the product that happened because of chipped substances on the edges during milling can be defined with the help of this process. During the investigation we used NC controlled stone machining centers, laser scanners and rapid prototyping softwares. During the research we have defined the shape that could replace the chipped parts with great precisions

A Note on the Role of Internal Structure of Rocks in the Deviations of Compression Strength Results

Our paper focuses on the uniaxial compression failure strength of granular rocks. The results of laboratory tests usually show a rather high scatter that has mostly been explained by the small random errors when doing the experiments. Our aim was to supervise this problem from microstructural point of view and to point out that the geometrical randomness of microstructure has a significant role in the differences between the results of individual tests

Relationship between the critical dissipated energy per unit volume and the mechanical properties of different rocks

The aim of this paper is to present a laboratory method determining the critical dissipated energy (CDE) per unit volume of homogenous-isotropic rock. In case of uniaxial compression it can be calculated easily with the difference of the work done by external force and the energy connected to the change of internal structure. These energies are measured applying different stress or strain rates, i.e. it tends to infinite and zero. The CDE is material dependent: it is influenced by the rock texture, internal bonds, the cohesion, the strength of the minerals, the porosity, etc. Using seven different type of rocks the CDE was measured and the relationship with the compressive and tensile strength, ultrasonic wave velocity and porosity was calculated

Age- and sex-related regional compressive strength characteristics of human lumbar vertebrae in osteoporosis

Márta Kurutz1, Judit Donáth3, Miklós Gálos2, Péter Varga1, Béla Fornet41Department of Structural Mechanics; 2Department of Construction Materials, Budapest University of Technology and Economics, Budapest, Hungary; 3Department of Reumatology, National Institute for Reumatology, Budapest, Hungary; 4Department of Radiology, County Hospital András Jósa, Nyiregyháza, HungaryObjective: To obtain the compressive load bearing and energy absorption capacity of lumbar vertebrae of osteoporotic elderly for the everyday medical praxis in terms of the simple diagnostic data, like computed tomography (CT), densitometry, age, and sex.Methods: Compressive test of 54 osteoporotic cadaver vertebrae L1 and L2, 16 males and 38 females (age range 43–93, mean age 71.6 ± 13.3 years, mean bone mineral density (BMD) 0.377 ± 0.089 g/cm2, mean T-score −5.57 ± 0.79, Z-score −4.05 ± 0.77) was investigated. Based on the load-displacement diagrams and the measured geometrical parameters of vertebral bodies, proportional, ultimate and yield stresses and strains, Young’s modulus, ductility and energy absorption capacity were determined. Three vertebral regions were distinguished: superior, central and inferior regions, but certain parameters were calculated for the upper/lower intermediate layers, as well. Cross-sectional areas, and certain bone tissue parameters were determined by image analysis of CT pictures of vertebrae. Sex- and age-related decline functions and trends of strength characteristics were determined.Results: Size-corrected failure load was 15%–25% smaller in women, proportional and ultimate stresses were about 30%–35% smaller for women in any region, and 20%–25% higher in central regions for both sexes. Young’s moduli were about 30% smaller in women in any region, and 20%–25% smaller in the central region for both sexes. Small strains were higher in males, large strains were higher in females, namely, proportional strains were about 25% larger in men, yield and ultimate strains were quasi equal for sexes, break strains were 10% higher in women. Ultimate energy absorption capacity was 10%–20% higher in men; the final ductile energy absorption capacity was quasi equal for sexes in all levels. Age-dependence was stronger for men, mainly in central regions (ultimate load, male: r = −0.66, p < 0.01, female: r = −0.52, p < 0.005; ultimate stress, male: r = −0.69, p < 0.01, female: r = −0.50, p < 0.005; Young’s modulus, male: r = −0.55, p < 0.05, female: r = −0.52, p < 0.005, ultimate stiffness, male: r = −0.58, p < 0.05, female: r = −0.35, p < 0.03, central ultimate absorbed energy density, male: r = −0.59, p < 0.015, female: r = −0.29, p < 0.08).Conclusions: For the strongly osteoporotic population (BMD < 0.4 g/cm2, T-score < −4) the statical variables (loads, stresses) showed significant correlation; mixed variables (stiffness, Young’s modulus, energy) showed moderate correlation; kinematical variables (displacements, strains) showed no correlation with age. The strong correlation of men between BMD and aging (r = −0.82, p < 0.001) and betwen BMD and strength parameters (r = 0.8–0.9, p < 0.001) indicated linear trends in age-related strength loss for men; however, the moderate correlation of women between BMD and aging (r = −0.47, p < 0.005) and between BMD and strength parameters (r = 0.4–0.5, p < 0.005) suggested the need of nonlinear (quadratic) approximation that provided the better fit in age-related strength functions of females modelling postmenopausal disproportionalities.Keywords: osteoporosis, human lumbar vertebral body, regional compressive strength, load, stress, strain, young’s modulus, energy absorption capacity, age- and sex-dependenc