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STRUCTURAL STABILITY MODELS FOR CULTURAL HERITAGE

Europe implement policies in an effort to preserve their cultural heritage, a very important part of their national history and an integral part of European tradition. A major objective of the STABLE project is to address earthquake risk maps of cultural heritage sites through the development of vulnerability assessment.

Keyword: Cultural Heritage, European project, Structural stability

In STABLE (STructural stABiLity risk assEssment – Grant Agreement No: 823966) one of the goals is to summarize the various methods used for the vulnerability assessment and conclude with the required parameters that need to be collected from each structure of the chosen case studies.

The consortium members working on the vulnerability assessment that will be performed with the implementation of a simplified method such as the macroseismic method while at the same time, for a selection of buildings, it will be performed following a more elaborate method such as the analytical, which requires the simulation of 3D models in a finite element software.

The damage potential of buildings subjected to earthquakes can be represented by a series of curves, namely the fragility curves, which provide the probability of reaching or exceeding a given damage level as a function of the intensity of the earthquake. The information coming from the fragility curves and the implementation of statistics can produce the vulnerability curves.

Exploiting the experience from recent earthquakes have provided more data that have been useful in developing models to better assess the performance of structures in order to estimate the economic losses to structures and lifelines and the social consequences such as casualties and needs for provisional accommodation.

In STABLE the case studies are analyzed with various methods (depending on the objective of the assessment but also on the availability of data and technology), investigating the vulnerability of the built environment with the hazard scenarios as the first fundamental step in the seismic risk mitigation process.

The expected risk is determined according to the following expression: Risk = Hazard × Vulnerability, where:

  • Hazard: as defined for the seismicity of the region and the accepted probability of exceedance,
  • Vulnerability: as expressed by the defined capacity of the structure as described in the following.

The estimation of damage probability will be performed by means of a simplified mechanical methodology, based on this input parameters:

  • Geometrical data (total height, number of storeys, perimeter, footprint area, average bearing wall thickness for masonry structures, Plan view at least of the ground-floor, etc)
  • Use (residential, commercial, etc.),
  • Year of construction and the relevant specification.

Article by: Matteo Serpetti

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STABLE PROJECT: LAND MOVEMENTS MONITORING METHODS, ANALYSIS AND TECHNIQUES. STATE OF ART

A project to introduce a strategy and select most efficient methods and tools for harmonization of data, criteria and indicators to be addressed for tracking of impact of environmental changes on tangible cultural heritage assets, buildings and monuments, including structural deterioration processes at a city/village scale.

Keyword: Cultural Heritage, European project, Historical Centres

 

Inside the project STABLE (co-funded by the European Commission, carried out in the context of the HORIZON 2020 program supervised by EU Authority – Grant Agreement No: 823966), the consortium members are working on the structural stability risk assessment of the cultural heritage.

In particular a part of the activities are focused on the monitoring methods and the techniques that will be used for STABLE project purposes, that is to build the deformation model and the geological, geotechnical and seismostratigraphic model of the test sites, using information coming from in-situ and satellite SAR remote sensing, optical data and geophysical methods.

The objectives are two: identify the critical areas and/or structures affected by deformation phenomena, and build the geological, geotechnical and seismostratigraphic model of the subsoil, and provide three-time histories for each seismic ambient noise measurement, representing the three components of the motion.

Until now the consortium are working on three cases study: Rieti (Italy), Nauplion (Greece) and Strovolos (Cyprus)

The Strovolos (CY) case study.

From June 2019 the Strovolos area was under study with acquisition campaigns to define the seismic ambient noise (seismostratigraphic model of the subsoil), in the perspective of providing the expected seismic shaking parameters by the subsequent local seismic response analysis, integrated all with data coming from engineering geological setting and other geological information. 

The definition of the structure and the composition of the Strovolos area, allowed to classify the case study as a non-resonant site characterized by an outcropping seismic bedrock.

Article by: Matteo Serpetti

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Stable main case study site in Greece: Historical City of Nafplion

GSH team dealt with photogrammetric image analysis of Nafplion, with the aim of estimate the geometrical characteristics of the buildings selected for assessing the structural vulnerability, according to the information shared with the NTUA group.


In the following picture the RGBNIR stereomodel from airborne acquisition at 0.20 cm

In next picture some results of 3DCity Building modeling realized using LOD2 accuracy and standard for the Building Information Modeling (BIM).