Long-term geotechnical monitoring of crack and fissure movements in slope deformations, historical buildings, as well as underground objects in Slovakia, provided results that bear evidence of movement trends, as well as of present tectonic unrest. The results were subject to an analysis regarding anomalies in movements that would verify activity of a specific geodynamic process. Such a process was detected recently in the Bohemian Massif and evidenced even in other European countries, north as well as south of the Alps. The process began by a tectonic pressure pulse and followed by a phase of increased geotectonic activity. The search for signs identifying this process on the Slovak territory which belongs to a different geological unit than the Bohemian Massif was successful. This is further evidence that the process in question is of a very deep foundation. The investigations proved successful long-term outdoor operation of TM71 crack gauges working on the principal of mechanical interference between optical grids. A thirty year long record was even reached. A useful function of the gauge which allows for supplementary data about angular deviations in faults has been found useful in the analysis. The data indicate affinity of the process to a large global disturbance in the Earth crust., Ľubomír Petro, Blahoslav Košťák, Josef Stemberk and Ján Vlčko., and Obsahuje bibliografii
At the end of 2010 seven TM 71 extensometers, installed at or near the active faults in Slovenia, were in operation. Three of them are on the surface and four inside karst caves. The highest rates with stable sense of movements were observed on the Idrija fault. Average horizontal displacement rate was 0.24 mm/year. Short term rates were even greater and reached 0.54 mm/year. The Raša fault first experienced an uplift of the SW block of 0.16 mm/year, which was followed by a short-term down-slip of the same block at the rate of 0.37 mm/year. Later the sense of movement returned to uplift with a rate of 0.05 mm/year. The average horizontal displacement was 0.07 mm/year. The Kneža fault experienced very small average displacements (y=0.035 mm/year, z=0.03 mm/year and x=0.02 mm/year). Similar rates were observed in nearby Polog cave (y=0.015 mm/year, z=0.027 mm/year and x=0.016 mm/year), which is located close to the seismically active Ravne fault. For Kostanjevica cave, located near the Brežice fault, small average rates are characteristic (y=0.006 mm/year, z=0.017 mm/year and x=0.012 mm/year). In Postojna cave, located close to the Predjama fault, two monitoring sites are very stable with small tectonic movements, including general dextral horizontal movement of 0.05 mm from 2004 to 2010 (Postojna 1) and two significant short-term peaks of 0.08 mm (Postojna 1-y and Postojna 2-z)., Andrej Gosar, Stanka Šebela, Blahoslav Košťák and Josef Stemberk., and Obsahuje bibliografii
Three year monitoring of micro-displacements on four tectonic fracture planes in a tunnel driven by a milling cutter into granitoids of Bohemian Massif revealed micro-movements that develop in certain trends and impulses. Two investigated fractures are of the Krušné Hory Mts. orientation (NE - SW), other two of Sudeten orientation (NW - SE). These have been found the two prevailing fracture orientations in the massif. Results from all the four fractures indicate trends in overfaulting of southern blocks over the northern ones and a stress state model characteristic of approximate N-S compression with overthrust vergence to N. Besides, some impulses were indicated with abrupt occurrence that dominates the development of movements. The first most significant impulse occurred by the end of the year 2004, the second one at the break of 2005/6. The coincidence of the impulses with earthquake events is discussed., Josef Stemberk and Blahoslav Košťák., and Obsahuje bibliografii
The results obtained by four years long TM 71 extensometer monitoring of 3D micro-tectonic displacements of Dinaric Fault Zone on two sites, being 260 m apart in Postojna Cave, were statistically evaluated with different methods (Kolmogorov- Smirnov test, comparison between relative displacement and earthquakes, linear regression, Kruskal-Wallis one-way analysis of variance, histograms and correlation coefficients). Responses to stress changes regarding x, y and z-axes are not the same on two monitoring sites even if we are monitoring the same fault zone. Kolmogorov-Smirnov test for comparing the two curves is applicable only for three axes combination (Postojna 1 z - Postojna 2 z, Postojna 2 y - Postojna 1 z, and Postojna 2 z - Postojna 2 y). Kruskal-Wallis analysis is most representative for z-axes. Some sharp peaks coincide with earthquake occurrences (Krn M=5.2, Cerkno M=4.0, Ilirska Bistrica M=3.9, Brežice M=2.9 and Krško M=3.1). Generally we detect very small tectonic deformations, dextral horizontal movement of 0.05 mm in 4 years for Postojna 1 and extension of 0.03 mm in 4 years for Postojna 2. Discrepancies between two sites can be attributed to complex geological structure and by the fact that studied fault zone is cut by cross-Dinaric fault zone., Stanka Šebela, Janez Turk, Janez Mulec, Blahoslav Košťák and Josef Stemberk., and Obsahuje bibliografii