We studied the geophysical, physical, and geomechanical parameters of the Podlesí granites in the western part of the Krušné hory Mts., near the village of Potůčky. The granites represent a fractionated intrusion within the Nejdecký Massif. In total, the studied borehole is about 300 m deep. The samples were collected at depths of between 35 and 105 metres. Seismic P-wave and S-wave velocities were measured using ultrasonic scanning. The samples were water-saturated, unsaturated, and dried. The ultrasonic scanning system consisted of four piezoelectric sensors and a digital oscilloscope recorder. The wave frequency was 1 MHz. P-wave velocities range from 4400 m.s-1 to 6500 m.s-1 while S-wave velocities range from 2800 m.s-1 to 3800 m.s-1. These data were used to calculate dynamic Young’s modulus, dynamic shear modulus, and Poisson’s ratio. The deformational characteristics of the rock were specified from experimental loading of the sample with uniaxial strain. The shear and longitudinal deformation of each sample was measured using a resistive strain gauge fixed directly on the sample. Intermittent loading of the samples proceeded using a uniform gradient of axial stress of 1 MPa.s-1. The samples were subjected to five separate loads. During the tests, following parameters were recorded: stress, longitudinal deformation, and shear deformation. These data were used to calculate static Young’s and shear modulus, and Poisson’s ratio., Lucie Nováková, Karel Sosna, Milan Brož, Jan Najser and Petr Novák., and Obsahuje bibliografii
The Accelerated Failure Time model presents a way to easily describe survival regression data. It is assumed that each observed unit ages internally faster or slower, depending on the covariate values. To use the model properly, we want to check if observed data fit the model assumptions. In present work we introduce a goodness-of-fit testing procedure based on modern martingale theory. On simulated data we study empirical properties of the test for various situations.
This paper investigates the matrix porosity and related properties of a leucocratic granite from the Krudum Massif, West Bohemia. The required samples were obtained from the 30-year old core of borehole KZ-25 (Material Documentation Depositories). In total, nine sample sets were taken from different depth levels within the borehole ranging from 18 m to 108 m. The hydraulic conductivity of the granite matrix was measured using a pressure cell whilst standard methods were employed to determine the dry density, connected porosity and total porosity. The pore size distribution was analysed using mercury porosimetry. The ultrasonic velo cities were measured using a pulse source and oscilloscope. Dynamic Young’s modulus, dynamic shear modulus, Poisson’s ratio, static Young’ s modulus, uniaxial compressive strength and moisture were determined according to measurements of ultrasonic velocities and deformability in uniaxial compression. The morphology and structure of the pore network was studied using high reso lution scanning electron microscopy. The overall porosity values defined by the different porosimetry methods follow the same trends although the absolute values differ according to the specific method. A logarithmic relationship was found to exist between hydraulic conductivity and porosity within the granite matrix. In addition, a slight depth dependence was noted in the porosity, hydraulic conductivity, bulk density, and ultrasonic velocities of the granite matrix. The SEM images have allowed precise mapping and detailed de scription of the pore network., Lucie Nováková, Karel Sosna, Milan Brož, Jan Najser and Petr Novák., and Obsahuje bibliografické odkazy