Landslide hazard assessment, monitoring and conservation of Vardzia monastery complex

Abstract

The rock-cut city of Vardzia is a cave monastery site in south-western Georgia, excavated from the slopes of the Erusheti mountain on the left bank of the Mtkvari River. The main period of construction was the second half of the twelfth century. The caves stretch along the cliff for some eight hundred meters and up to fifty meters within the rocky wall. The monastery consists of more than six hundred hidden rooms spread over thirteen floors, which made possible to protect the monastery from the Mongol domination. The site was largely abandoned after the Ottoman takeover in the sixteenth century. The site is by the time affected by frequent slope instability processes along the entire volcanic tuff façade of the slope. Due to this phenomena the National Agency for Cultural Heritage Preservation of Georgia (NACHPG) has promoted, with the support of ISPRA, a landslide hazard assessment for the entire area through rock mechanics characterization, geotechnical engineering survey, geostructural and kinematic analysis, slope stability model, 3D laser scanner acquisitions and elaborations, and a real time monitoring system (GB_Radar interferometry) for the identification of deformation path of the most hazardous areas. A field analysis was conducted to reconstruct geometry of the rocky cliff, characteristics of discontinuities, main failure modes and volume of potential unstable blocks and geomechanical parameters.