Using GNSS method, fixed points of an observation network were repeatedly surveyed on the surface of the undermined area. Below the surface, at the depth of c. 1 km, there were four mining panels exploited subsequently. The main reaction of the surface points to the changes in the rock massif and the movement of the points were different, according to their surface position, local geo-mechanical conditions etc. This paper analyses the time-dependence of the surface points mining subsidence and horizontal movements on the progress of the exploitation., Hana Doležalová, Vlastimil Kajzar, Kamil Souček and Lubomír Staš., and Obsahuje bibliografické odkazy
High temperature alters the internal microstructure of rocks and consequently changes the physical and mechanical properties of rocks. Many studies have been carried out to examine the transformations in the microstructures of rocks under high temperature through near infrared spectroscopy (NIR), Raman spectroscopy, or thermo gravimetric analysis (TGA). The current review synthesizes the data from a number of literatures and summarizes the major transformations of silica rocks under high temperature. The analysis shows that silica rocks starts to lose the water adsorbed in open pores upon heating at about 150 °C. At 200-300 °C, the reaction between SiOH (silanole) in the rocks generates new Si-O-Si bonds as well as H2O, and decreases the open pores. The rocks undergo volume expansion at >550 °C, and the volume contracts and forms new micro pores or cracks which play an important role in the evacuation of the water., Jishi Geng, Qiang Sun, Yuchun Zhang and Yuliang Zhang., and Obsahuje bibliografické odkazy
Persistent Scatterer Interferometry (PSI), a remote sensing technique, is used for detecting surface deformation in the cities of Prague and Ostrava. PSI is able to detect vertical movements with an accuracy of less than 1 mm for a long time series of the SAR data, but the maximum detectable rate of movement is only a few centimetres per year. This technique is quite suitable for detecting recent movements in most Prague localities. On the other hand, in Ostrava and its surroundings, affected by undermining, where subsidences (1992-2006) amount to decimetres per year, movements cannot be fully detected by the PSInSAR technique. The paper presents results of analysing PSI data for two localities in Prague and one locality in the Ostrava areas. The localities are strictly situated in built-up areas with many suitable reflectors. Data from the ERS-1/2 and ENVISAT satellites covering a 13-year period for the Prague (1992-2005) and a 14-year period for the Ostrava (1992-2006) area were used. Annual movement velocities and time-series of reflectors were determined. At these three localities, where different types of movements were identified, the application and possible limitations of PSI in urban areas are shown., Pavel Kadlečík, Vladimír Schenk, Zuzana Seidlová and Zdeňka Schenková., and Obsahuje bibliografii
The main objective of this paper is to explain how the application of various interpolation methods influence the determination of vertical crustal movements at any given point. The paper compares several methods of interpolation and verifies their suitability, including kriging, minimum curvature, nearest neighbor, natural neighbor, polynomial regression, inverse distance to a power, and triangulation with linear interpolation. The calculations show that the chosen interpolation method has significant influence on the final result of the study. Nearest neighbor method was chosen to be the best., Kamil Kowalczyk, Jacek Rapinski and Marek Mroz., and Obsahuje bibliografii
The orientation of the Earth is defined by Earth orientation parameters that are measured by space geodetic techniques. The results provided by these techniques differ from each other. The method presented here combines these results in order to get a representative solution of the Earth orientation parameters. Other products of the method are improved coordinates and velocities of collocations stations distributed on six major and two minor tectonic plates. The fact that the stations lie on their plates gives us possibility to describe movements of these plates during our data interval. All new results are compared with the ones published by ITRF 2005 and presented hereafter., Vojtěch Štefka., and Obsahuje bibliografii
Fractures commonly existing in rocks flow on their elastic properties and hence on velocity of seismic waves propagating in the rock mass. This relation allows to use seismic methods to determine the fracture density and the orientation of fracture sets. This paper presents results of the research which concern directional changes of dynamic elastic moduli in sedimentary and igneous rocks from south part of Poland. These moduli depend on density of the rock matrix as well as density and orientation of cracks and flow on seismic wave velocity. The seismic equipment Terraloc MK6 (ABEM) was used for the measurements of seismic wave velocity in the surface layers of rock mass. The research was made along precise oriented radial seismic profiles. P-waves and S-waves ve locities were established from recorded seism ograms. The values of P and S waves velocity allowed to calculate values of dynamic elastic moduli for all profiles. The results were presented on diagrams of azimuth distribution of elastic moduli, and diagrams of dynamic elastic moduli versus P - wave velocity. The diagrams showed an anisotropy of elastic properties of the investigated rocks. The maximal values of moduli agree with maximal values of velocity and also with orientation of main crack sets or potential directions of weakening of rock mass. Obtained results point that the seismic methods allow to assign the directions of weakening of rocks what can be for example use during preliminary designing, constructing and exploitation of tunnels., Iwona Stan - Kleczek and Adam F. Idziak., and Obsahuje bibliografické odkazy
A new way of identification of minerals was suggested. The identification was based on chemometric analysis of measured IR spectra of selected minerals. IR spectra were collected using diffuse reflectance technique. The discriminant analysis and principal component analysis were used as chemometric methods. Five statistical models were created for separation and identification of clay minerals. Up to 60 samples of various mineral standards (clay minerals, feldspars, carbonates, sulphates and quartz) from different localities were selected for the creation of statistical models. The results of this study confirm that the discriminant analysis of IR spectra of minerals could provide a powerful tool for mineral identification. Even differentiation of muscovite from illite and identification of mixed structures of illite-smectite were achieved., Michal Ritz, Lenka Vaculíková and Eva Plevová., and Obsahuje bibliografii
Classical Russian pendulum seismometer S-5-S was modified for recording of the rotational components of ground motion around the vertical or horizontal axes; the modified sensor is denoted here as S-5-SR. Experimental field testing of the S-5-SR sensor started in December 2010 in the Karvina coal region that is known as an area of intensive mining induced seismicity. First seismic station was installed in Doubrava village characterized by thick sedimentary layers. Next seismic station was installed in Orlova village, in different local geological conditions, i.e. in region without sedimentary layers. More than 200 mining induced seismic events were recorded on each seismic station during the period of six months of seismic monitoring. The recorded wave patterns confirm the existence of rotational ground motion components in this region; the strongest recorded value of this component exceeded 1 mrad.s-1. Analysis of the obtained records is presented in this paper., Zdeněk Kaláb, Jaromír Knejzlík and Markéta Lednická., and Obsahuje bibliografii