Rock Mechanic Characterization and 3D Kinematic Analysis of Katskhi Pillar (Georgia)

Katskhi pillar is a natural limestone monolith located close to Katskhi village in western Georgian region of Imereti, near the town of Chiatura. It is approximately 40 m high, and overlooks the small river valley of Katskhura, a right affluent of the Q'virila river. On top of the pillar a small church is located, together with the house of the unique monk guardian taking care of the site. The pillar is affected by slope instability in its rocky components and his long time of standing is not clear. A 3D laser scanner (TLS), integrated with drone survey, has been conducted in order to identify the geometry and slope conditions of the pillar. Point clouds have been also used for automatic identification of rock mass structural setting, integrated with traditional manual survey. Geological, geomorphological and geotechnical data have been collected to define the main strength and deformation parameters, integrated with passive seismic surveys, to achieve information about resonant frequency of the site. Finally, the integration of 3D point clouds with rock mechanic parameters, allowed the realization of an advanced kinematic analysis for the whole pillar and identifying most potential unstable areas. Some preliminary proposals for monitoring and mitigation have been provided.