Kinematic Analysis of a Rock Slope at Strecno Castle (Slovakia) Based on the Processing of the Point Cloud Generated by UAV Photogrammetry

Abstract

The Strecno Castle (northern Slovakia) stands upon rock cliff formed by Triassic dolomite-limestone rocks which are in overthrusted position. At the toe of the castle rock in relatively narrow area the Váh River, international railway and the primary international road with large volume of traffic is running. Due to extreme morphology formed by almost vertical slopes with several overhangs, lithological composition, tectonic setting and the high degree of weathering, the rock mass is in critical state of stability. Following this situation and having in mind one causality from 2008 when one person in car was killed by the falling rock block, the Ministry of the Environment initiated the programme covering detailed engineering geological investigation including elaboration of kinematic analysis of the rock slope based on the high density point cloud data generated by UAV photogrammetry to delineate potentially unstable parts in the rock slope. The authors describe the procedure of identifying critical structural data sets delineating potentially unstable rock blocks, type of down fall movement and rock fall trajectories. This, along with detailed stability calculation of the critical rock blocks serves as powerful tool to recommend mitigation measures needed to secure the international road and the castle, as well.