High-Resolution 3D FEM Stability Analysis of the Sabereebi Cave Monastery, Georgia

This study assesses the static stability of the artificial Sabereebi Cave Monastery southeast of Georgia's capital, Tbilisi. The cliff into which these Georgian-Orthodox caverns, chapels, and churches were carved consists of a five-layered sequence of weak sedimentary rock—all of which bear a considerable failure potential and, consequently, pose the challenge of preservation to geologists, engineers, and archaeologists. In the first part of this study, we present a strategy to process point cloud data from drone photogrammetry as well as from laser scanners acquired in- and outside the caves into high-resolution CAD objects that can be used for numerical modeling ranging from macro- to micro-scale. In the second part, we explore four distinct series of static elasto-plastic finite element stability models featuring different levels of detail, each of which focuses on specific geomechanical scenarios such as classic landsliding due to overburden, deformation of architectural features as a result of stress concentration, material response to weathering, and pillar failure due to vertical load. With this bipartite approach, the study serves as a comprehensive 3D stability assessment of the Sabereebi Cave Monastery on the one hand; on the other hand, the established procedure should serve as a pilot scheme, which could be adapted to different sites in the future combining non-invasive and relatively cost-efficient assessment methods, data processing and hazard estimation

Tourism as a tool for natural hazard protection and territory development: Civita di Bagnoregio (Viterbo, Italy) as a case study

The village of Civita di Bagnoregio (Viterbo, Italy) represents a surreal landscape generated by accelerated soil erosion. The active landslides and erosive phenomena which are affecting Civita contributed to the progressive reduction of its surface and to its depopulation and currently require advanced engineering solutions to mitigate their impact. Furthermore they contributed to internationally increase the village fame, resulting in an increasing number of visitors over last years. The increasing touristic pressure on the village has been evaluated by taking into account also possible rising due to the recent candidature of Civita di Bagnoregio to the UNESCO’s World Heritage List (WHL). The high touristic pressure is triggering new critical issues highlighting the absence of a proper management plan: the data analysis highlighted the need to develop appropriate tourist numbers management strategies, considering also a partial re-investment of entrance fees for activities aimed to safeguard the village. The present research highlight that effects of tourist flows attracted by Civita di Bagnoregio could substantially contribute to both the safeguard of the village and the economical development of the territory. Properly distributed in the area by planning tourism decentralization policies based on an integrated valorisation of the territory it would be also possible to expand benefits deriving from the tourism sector to the entire Teverina area, transforming a stress factor into a development vector for the whole territory and the local population

Multiscale Analysis of Geo-Hazards Affecting the Alhambra Cultural Heritage

[EN] This paper presents a multiscale methodology to perform successful geo-hazards assessment in the context of Cultural Heritage. The methodology, defined in the European PROTHEGO project, has been applied to the Alhambra case study. Alhambra is an important Word Heritage site located in Andalusia, Spain. The site is prone to suffer flood, earthquake and landslide phenomena. The proposed multiscale methodology leans on new remote monitoring and modelling technics that not entail aesthetic and functional impacts on the site. For large-scale monitoring, satellite remote sensing technology enables to detect and characterize spatiotemporal ground and structure deformation as a whole, with up to millimeter precision. For very local phenomena analysis, small-scale monitoring based on Terrestrial Laser Scanner and airborne drone digital photogrammetry surveys enables to detect erosion processes that affect the slopes of the citadel. Furthermore, numerical modelling enables geo-mechanical instabilities to be quantified at different scales. Large-scale modelling shows that the most dangerous slope is located at the San Pedro cliff site. Small-scale stability analysis in the San Pedro cliff shows that a slope failure, triggered by a possible earthquake scenario, could reach the wall foundations of the Alhambra citadel located 22 m behind it. Finally, very detailed small-scale modelling, using very precise digital elevation models, enables to track local instabilities and erosion phenomena. Such a multiscale, interdisciplinary approach is the most effective way to identify, assess and monitor risks, strengthening disaster preparedness at heritage property.The research leading to these results has been supported by the PROTHEGO Project (Protection of European Cultural Heritage from Geo-hazards), funded through the framework of the Joint Programming Initiative on Cultural Heritage and Global Change (JPICH), and under ERA-NET Plus and the Seventh Framework Program (FP7) of the European CommissionPeer reviewe

Floods and landslides : integrated risk assessment

xx, 373 p. : ill., maps ; 25 cm

Cultural heritage and landslides: research for risk prevention and conservation

In this chapter we briefly introduce and review the interrelated concepts of mapping landslide inventories, susceptibility, hazard and risk. We emphasize the importance of extensive metadata in the characterization of landslides stressing the need for spatial information, type, abundance, age, triggering mechanism, failure parameters (slope angle, material, etc.) and volume data as basic properties of any proper inventory. Concomitantly we comment on the representation of these data in map form via scale and symbology. We examine the differences between landslide susceptibility and hazard mapping, commenting on a few of the better known qualitative (heuristic) and quantitative (statistical-probabilistic) methods of analysis. Added attention is given to a comparison between bivariate and multivariate statistical approaches. Finally we refer to the important but difficult task of addressing landslide risk, implicating the inherent relationship of landslide hazard, exposure and vulnerability. Additionally, quantitative and qualitative approaches to risk assessment and mapping are briefly discussed. Moreover, we highlight the need for more extensive hazard and risk mapping, as well as for the application of harmonized, comparable approaches to susceptibility, hazard and risk assessment where possible. The first part of this chapter provides the prelude to a number of presentations which individually deal with topics already discussed. The extended abstracts that follow represent those presentations which can provide good case study examples of relevant issues in mapping landslide inventories, susceptibility, hazard and risk.JRC.H.7-Land management and natural hazard

Advances in Geotechnical Investigations and Monitoring in Rupestrian Settlements Inscribed in the UNESCO's World Heritage List

AbstractRupestrian settlements were among the first man-made works in the history of humanity. The most relevant masterpieces of such human history have been included in the UNESCO World Heritage List. These sites and remains are not always in equilibrium with the environment. They are continuously impacted and weathered by several internal and external factors, both natural and human-induced, with rapid and/or slow onset. These include major sudden natural hazards, such as earthquakes or extreme meteorological events, but also slow, cumulative processes such the erosion of rocks, compounded by the effect of climate change, without disregarding the role of humans, especially in conflict situations. Many rupestrian sites have been carved into soft rock, generally with UCS<25 MPa (ISRM, 1981), in vertical cliffs, and showmajor conservation issues in the domain of rock slope stability and rock weathering. The present paper reports the experience of rock fall investigation and monitoring in rupestrian sites, mainly from the UNESCO World Heritage List (Bamiyan in Afghanistan; Lalibela in Ethiopia; Petra in Jordan and Vardzia in Georgia). The general approach, implemented in the activities, include an interdisciplinary study with advanced methodologies and technologies, with the objective to understand degradation processes and causative factors, followed by low impact, but highly effective, rock slope monitoring

Rapid assessment of geo-hydrological hazards in Antananarivo (Madagascar) historical centre for damage prevention

The historical centre of Antananarivo represents one of the most important cultural heritage sites in Madagascar. During 2015, the whole city area was severely affected by geo-hydrological hazards due to cyclonic rain, resulting in severe flooding, and in widespread shallow landslides along the hillslopes. This event proved the vulnerability to geo-hydrological risk of the Upper town’s historical buildings. In October 2017, a geo-hydrological hazard mapping was performed in the Upper Town by combining field surveys, remote sensing and geomatic data analysis in a GIS environment. This provided detailed products such as a geological- geomorphological map, a map of the hydrographic network and of the creek basins, and a geodatabase to be used for detecting areas prone to erosion and geo-hydrological hazards. The final aim was to understand the geological, geomorphological and hydrographic features of the Upper Town, in order locate the more critical areas and to recommend priority works to be carried out, as a first step toward a risk management strategy and a conservation/ valorization plan for building the resilience of the site. The results highlighted that a Cultural Heritage site protection strategy can be planned also in case of limited data, which is a frequent condition in developing countries