Kinematische Analyseder BergzerreiBung Hornbergl — Reutte(Tirol)

摘要

Owing to geotechnical studies over a period of twenty years the process of spreading of mountain ridges could be analysed. The kinematical stu-dies were carried out on the mountain splitting area Hornbergl – Reutte/Tyrol. The Hornbergl – "Fauler Schrofen" area with the "Murenbach and Her-renbach" torrent is situated in the Northern Calcareous Alps approx. 10 km southwest of Reutte in a chain of mountains, which frames the Reutte basinat a length of 6 km. The investigated study area is located in the forehead of the "Lechtaldecke" nappe, which has been overthrust onto the "Allgau-decke" nappe. Layered limestone ("oberer alpiner Muschelkalk") of the "Lechtaldecke" nappe builds up the mountain splitting area. The limestonepackages of the "oberer alpiner Muschelkalk" are characterized by clearly marked and persistent dipping downhill bedding surfaces. Between the thickbedded limestones there are embedded semiindurated marl layers (thickness some cm) which alternate with small rock connections which bridge theductile marl layers. Additionally we have two joint systems perpendicular to the bedding surfaces. Opening of cracks, formation of spreading zones,and rock falls accompanied by debris flows (e. g. events taking place in 1975, 1982 and 1983) as well as rockslides/cliff falls (1976) clearly indicatemountain splitting mechanisms. With the aid of comprehensive monitoring of the kinematics, which included periodic geodetic and extensometer measurements, the specific move-ment behaviour, displacement rates and the varying influence of external factors could be detected.