Landslide hazard, monitoring and conservation strategy for the safeguard of Vardzia Byzantine monastery complex, Georgia

Abstract

This paper reports preliminary results of a feasibility project developed in cooperation with National Agency for Cultural Heritage Preservation of Georgia, and aimed at envisaging the stability conditions of the Vardzia monastery slope (rupestrian city cave in the south-western Georgia). The aim is the implementation of a low-impact monitoring system together with long-term mitigation/conservation policies. 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. Instability processes are the combination of causative factors such as the following: lithology, frequency and orientation of discontinuities, slope orientation, physical and mechanical characteristics of slope-forming materials, and morphological and hydrological boundary conditions. The combined adoption of different survey techniques (e.g., 3D laser scanner, ground-based radar interferometry) could be the best solution in the interdisciplinary field of cultural heritage preservation policies. The collected data will be the basis for future activities to be completed in collaboration with local authorities for a complete hazard and risk characterization for the monastery site and the development of an early warning system to allow safe exploitation for touristic activities and for historical site preservation.

Slope stability and rock fall hazard assessment of volcanic tuffs using RPAS and TLS with 2D FEM slope modelling

“…The frequency of joints was observed based on these images. Similar approach was used in previous studies by Assali et al 2014, Martino & Mazzanti 2014and Margottini et al 2015. It is necessary to emphasize that with the sole use of these remote sensing techniques, it is not possible to detect precise joint orientation.…”

“…10 rebound values were measured on each surface and mean values and standard deviations were also calculated. This method has been also used previously to gather 10 rapid data on rock strength of cliff faces (Margottini et al 2015). The data-set was compared to rock mechanical laboratory tests.…”

“…In contrast, very few previous studies 20 deal with cliff face stability and rock fall hazard of low strength rock such as volcanic tuffs (Fanti et al 2012, Margottini et al 2015. Volcanic tuffs are very porous rocks and prone to weathering (Arikan et al 2007).…”

“…Slope profiles can be obtained by TLS or RPAS, while material properties have to be measured on site (e.g. UCS by Schmidt 15 hammer) or under laboratory conditions (Margottini et al 2015). Detection and mapping of joints require fieldwork (on site measuring by compass), or at hardly accessible locations it is possible by applying remote sensing techniques (Fanti et al 2012), or both.…”

Advanced Technologies for Landslides (WCoE 2014–2017, IPL-196, IPL-198)

“…1 reports the example of the Calatabiano landslide, which occurred in November 2016), all of them were monitored using advanced sensors and portable instruments such as ground-based synthetic aperture radar interferometer (GB-InSAR), terrestrial laser scanning (LIDAR), satellite interferometry (PS-InSAR), GPS antennas and infrared thermography and traditional instrumentation (e.g., strain gauges, inclinometers, piezometers) ( Fig. 1) Margottini et al 2015;Di Traglia 2014a, b;Gigli et al 2014a, b). Each time the best-integrated uses and synergetic approaches were evaluated.…”