This paper shows how the local effects can change the value of maximum accelerations from mining-induced tremors. The analysis was carried out basing on data collected from acceleration stations installed in Bytom Syncline region (Upper Silesia). The estimation of the local effects was obtained on the basis of deviations from the attenuation relation. The accelerograms were recorded from the mining tremors in low seismic energy range and in epicentral distances in the range from 500m to 5000m. The obtained re sults were correlated with results from Horiz ontal to Vertical Spectral Ratio (HVSR) technique. This method is based on simple theoretical founda tion and is commonly used in natural seismicity studies. Our results show that the H/V ratio technique gives a reasonable estimate of the surface amplification for frequency range between about 2 and 8 Hz. In case of simple geology and when the signal to noise is adequately high the results are the best. All the results show that there occur local effects., Adam Fref and Wacław Marian Zuberek., and Obsahuje bibliografické odkazy
This paper presents examples of application of the method of local quasigeoid modelling based on the geophysical technique of gravity data inversion, using non-reduced surface gravity data and GNSS/levelling height anomalies. Its capacity is demonstrated with three examples consisting in computing detailed local quasigeoid models for three areas situated in Poland. The test areas are different in size (3,900, 23,000, 117,000 sq. kilometres), in geographic location as well as in density of the gravity data coverage. For each of the test regions, calculations were done in three variants, viz. without using any global geopotential model and with application of EGM96 and EGM08 models. The obtained results indicate that the applied method is suitable for creating high accuracy local quasigeoid models (the accuracies obtained were at the level of accuracy of GNSS/levelling test data)., Marek Trojanowicz., and Obsahuje bibliografii
The paper presents analysis relating to the method of local quasigeoid modelling based on the geophysical technique of gravity data inversion, using non-reduced surface gravity data and GNSS/levelling height anomalies. One of the main problems occurring in the application of the method is to determine the model weighting matrix, the purpose of which is to control the inversion process. This paper presents the analyses concerning the determination of certain constant coefficients signed as, and, appearing in the definition of the model weighting matrix. The calculations performed indicate that because of the accuracy of the density model, the coefficient should be in the range of 01. 0 001. 0, and the range 005.00025.0 should be adopted as the optimal. As the optimal values of the coefficients and, values 1.0 and 01.0, for the zones of constant density with area less than about 130 km2 were determined., Marek Trojanowicz., and Obsahuje bibliografické odkazy
In October 2005 local seismic monitoring started in the area of the Hronov-Poříčí Fault Zone. In the present paper we summarize seismic measurements using a small-aperture seismic array Ostaš. Parameters of the array and methodology of the data registration and processing are described. The list of local microearthquakes during two years of registration is presented., Jiří Málek, Milan Brož, Vladimír Stejskal and Jaroslav Štrunc., and Obsahuje bibliografické odkazy
This paper is devoted to a complex review of various monitoring networks operating in the eastern part of the Ostrava- Karviná Coal Basin. In the first place, there were systems for monitoring seismo acoustic emissions during coal extraction. Later a local seismic network was installed which encompasses pa rtial arrays of seismic stati ons located in the individual mines underground. In addition, a special regional seismic network was established in order to ensure reasonable recordings of strong seismic events observed in this area. In 2001 an array was constructed with up to five surface seismic stations which monitor manifestations of rockbursts due to imposed dynamic loading on existing buildings at selected sites. Recently, a quite new monitoring system of accelerometers began operating, the purpose of which is to check the effects of rockbursts on surface structures. Using the output data of all monitoring systems, different graphs were constructed, which can faciliate geophysical interpretation of geodynamic processes in mines., Karel Holub, Josef Holečko, Jana Rušajová and Anna Dombková., and Obsahuje bibliografické odkazy
An approach to risk evaluation against the failure of waste deposit sealing layer is given. It is derived from experience gathered with municipal waste deposit closures. Such deposits were monitored in Ce ntral Bohemia in the territory of the Czech Republic. Geodetic observations on such deposits carried out for five to eleven years provided a chance to obtain and interpret continuous deformation data series. Results can increase functional reliability of their superficial sealing and can be used to optimise the time when closure and recultivation should start. The results concern superficial settlement, its development in time and irregularities that are practically very important. Definition of failure criteria that would allow evaluation of limits in irregular deposit se ttlement is relatively difficult and should become a topic for further investigations and discussions., Zdeněk Kudrna., and Obsahuje bibliografické odkazy
In the article the results of repeated satellite positional measurements of station VYHL of the Sněžník Network over period 1994-2006 are presented. Altogether 17 Brno University of Technology measuring campaigns were carried out and evaluated. The observation data (acquired mostly with Leica GPS receivers) were processed with the scientific Bernese GPS Software and the commercial Leica SKI-Pro software packets. Unified procedure for campaign data processing including the alignement of the resulting positions to respective EUREF Permanent Network weekly solutions had been adopted. Only the stability in horizontal direction was analysed. Positional stability of the VYHL station was considered in respect to the surrounding IGS, EPN, and local stations which were used for a local reference frame definitions, at three different levels. First level information was obtained from relations to surrounding stations of the Sněžník Network in distances up to 10 km, second level represent the relations to nearest EPN stations in distances about 100 km, and finally third level represent the relations to surrounding IGS Network stations in distances about 300 - 400 km. Another approach to VYHL stability assessment was the an alysis of slope distances time series from VYHL to neighbouring GPS stations. Outlined are also possibilities of exploitation of the recently completed CZEPOS Network., Otakar Švábenský and Josef Weigel., and Obsahuje bibliografické odkazy
In this paper, results from the long-term monitoring of two deep-seated slope deformations are presented. These deformations are considered typical of the types of landslide that occur in the high mountains of the Western Carpathians. The localities are situated in similar geological settings and this has enabled direct comparison of their development over the past 30 years. The monitoring has been undertaken using the extensometric gauges, TM71. At the Parohy Site, results from the scarp area show a significant vertical displacement trend of 0.07 mm per year. At the Štrochy Site, results from the crown area show a horizontal crack opening trend of 0.015 mm per year. Monitoring is ongoing at both sites., Miloš Briestenský, Blahoslav Košťák, Josef Stemberk and Jozef Vozár., and Obsahuje bibliografii
The static analyses and assessment of the technical condition of historical buildings in the Prague Castle Area are based on observational methods to gather the basic information about the behaviour of structures. The monitoring involves a combination of different methods of surveying, crack, inclination and temperature measurements together with the monitoring of dynamic effects of traffic and nearby tunnelling activities. These methods were enhanced by line-wise measurements using a high-precision sliding micrometer and inclinometer to assess the role of subsoil and to discover potential very slow slope movements in inclined parts of the area. The problems connected with long-term stability of historical buildings are further studied with the use of static analyses and numerical models of selected buildings in the area., Jaromír Procházka, Jan Záleský, Tomáš Jiřikovský and Jan Salák., and Obsahuje bibliografii