Aerial photogrammetry was chosen as an additional observation method of the subsidence depression that was created above exploited coal mining panels near Karviná. While individual points of a permanent observation network were repeatedly surveyed by GNSS, the whole subsidence depression was surveyed by the aerial photogrammetry. As this method was applied three times (during three years) we can compare its results in individual years and observe the major surface changes on the undermined area. Also, a comparison was realized between the points’ coordinates gained from both aerial photogrammetry and GNSS. The results show that the method of aerial photogrammetry enriches and complements the GNSS observation in monitoring the spatial development and shape of the subsidence depression, especially in the areas of active recultivation., Vlastimil Kajzar, Hana Doležalová, Kamil Souček and Lubomír Staš., and Obsahuje bibliografii
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
The observation network was built for the repeated determination of spatial position of points by means of the GPS method. It was built on the surface above extracted mining panels near Karviná, to monitor the development of subsidence depression in non-trivial geo-mechanical conditions. Two years of repeated surveying gave us the information about the process of creating of the subsidence depression in such area. The results gained so far show the important influence of the complicated tectonic situation on the behaviour of surface subsidence. A smooth development of subsidence depression without important irregularities was found out on sites without tectonic faults, while on sites where rock mass is disturbed with tectonic faults, the shape of subsidence depression is very irregular., Hana Doležalová, Vlastimil Kajzar, Kamil Souček and Lubomír Staš., and Obsahuje bibliografii
An observation network was built to observe the process of creating of a subsidence depression above exploited coal mining panels near Karviná. Points of the observation network were periodically surveyed by geodetic GPS method from 2006 to 2009. This method enables the evaluation of both vertical subsidence and horizontal shifts. Such complex evaluation of processes on the surface of the undermined area makes it possible to understand the progress of the subsidence depression caused by undermining. The results have shown on areas of irregular development of the subsidence depression. The irregularities are caused by a complicated tectonic situation and former exploitation in given locality and also active exploitation in the surroundings of given locality., Hana Doležalová, Vlastimil Kajzar, Kamil Souček and Lubomír Staš., and Obsahuje bibliografii
Using of shaped conical borehole bottom to determination of the stress tensor changes induced by changing of geomechanical situation is described in this paper. The measured strain changes on gauge probe are caused not only by the stress changes evocateg by progress of long wall. The some deformation started imediatelly after instalation when the long wal didn't move. In paper are discussed the eventu alities of this phenomenon too., Lubomír Staš, Kamil Souček and Jaromír Knejzlík., and Obsahuje bibliografické odkazy
A new observation network has been built to observe the surface manifestations of undermining at Gabriela locality. This locality lies in the Czech part of the Upper Silesian Coal Basin and the history of the hard coal underground exploitation is more than 150 years long here. Recently, the last coal mining panel was started to be exploited here. Its location and mining parameters are very suitable for the analysis of the actual and future surface changes caused by undermining. The fixed points of the observation network are surveyed by geodetic GNSS me thod. This method enables the evaluation of both vertical subsidence and horizontal displacements. Such complex evalua tion of processes on the surface of the undermined territory makes it possible to understand the progress of the subsidence depression and to capture the final phase of the surface undermining changes, i.e. the phase of the subsidence decline., Vlastimil Kajzar, Hana Doležalová, Kamil Souček and Lubomír Staš., and Obsahuje bibliografické odkazy
Compact conical strain gauge probe for borehole over-coring rock massif stress measurement (CCBO), based on experiences of K. Sugavara and Y. Obara, has been developed in Institute of Geonics ASCR, v.v.i. from 2004. First generation of CCBO is equipped by simple electronic circuit which requires continuous communication with control computer in the course of measurement. Prototypes of this type probes are used for long term stress changes monitoring induced by longwall advancement in mine. Solving of continuous data communication through rotating drilling tool filled by wash water in course of over-coring is very difficult technical task, which is not possible to solve in terms of grant project. To avoid this problem a development of second generation of CCBO equipped by microprocessor and internal data logger was initialised. Simplified modification of CCBO is developed as a probe for long-term monitoring of rock massif stress changes (Compact Conical Ended Borehole Monitoring - CCBM). Design of both models probes, discussion of measurement errors and technique of sensitivity self-calibration is described., Jaromír Knejzlík, Zdeněk Rambouský, Kamil Souček and Lubomír Staš., and Obsahuje bibliografii
Uranium deposits, between which gas storage are being designed, the Rožná deposit and Olší deposit, are situated on the east edge of the Strážek Moldanubicum in Bohemian Masiff. Based on structural analysis it was possible to carry out the first rough prediction of potential weak zones in the rock mass. The structural analysis was also one of the supporting materials for determining the geometry and design method for the mine workings for the gas storage and for the advancing exploration of the gas storage region. Until now, the measurement of foliation planes and discontinuity planes in the survey crosscut V1-XXI and in a survey connecting gate GR1-XXI has been carried out. The results of interpretation of the measurement and monitoring of ductile elements (foliations) and joints (ruptures) as well as dislocations interpretation from the mine maps can be summarized and quoted in the contribution., Jiří Ptáček, Rostislav Melichar, Antonín Hájek, Petr Koníček, Kamil Souček, Lubomír Staš, Petr Kříž and Josef Lazárek., and Obsahuje bibliografii
Generally, rock material failure is controlled by cracks under specific conditions. The study of rock fracture toughness belongs to the current frequent directions of research in the area of rock failure. The present paper describes the effects of parameters influencing the resultant properties of rock materials (bending rate, rock moisture) during fracture toughness measurement of different kinds of rocks (sandstone, marble, granite). The highest fracture toughness values were found in the marble samples. This is probably due to the inner structure of analysed marble, which is composed of only one mineral (calcite) and also has a lower porosity than the used granite. The lowest fracture toughness values were found in the sandstone sample, and reached c. 17-30 % of the measured fracture toughness values of the analysed granite and marble samples. As in the case of the other mechanical properties of rocks (e.g. uniaxial compressive strength) also in the case of higher sandstone (carboniferous) moisture the fracture toughness values decrease and its deformation ability increases. Preparation of samples for fracture toughness tests and performance of these tests are more complicated than in the case of tensile tests (e.g. the Brazilian test) and therefore this contribution presents a comparison between fracture toughness of analysed rocks and tensile strength values. The measured data in this study considering the fracture toughness tests and Brazilian tests were compared with results published by Zhang (2002)., Leona Vavro and Kamil Souček., and Obsahuje bibliografii