Landslide Hazard Affecting Historical Buildings: Santa Scolastica Monastery in Subiaco

== Abstract ==

Every year landslides occur as a consequence of ground conditions, geomorphological, physical or man-made processes, often triggered by heavy rainfalls or earthquakes. They affect buildings and infrastructures, causing economic and life losses. On the Italian territory, more than 14,000 heritage sites interact with potentially unstable slopes. 
This work investigates the effects of a landslide, occurred on the 26th of November 2018, on the Monastry of Santa Scolastica in Subiaco (Rome), one of the most ancient and well-preserved examples of medieval architecture in Central Italy. The geometry of the slope was reconstructed based on aerial photographic survey and point-cloud processing, obtaining meshed surfaces and extracting relevant sections. 
The mechanical parameters and the specific hydraulic conditions triggering the failure mechanism were first recognised by traditional limit equilibrium back-analyses and then implemented in a 3D non-linear finite element (FE) model, which included both the slope and the interacting portion of the ancient structure. Elastic-perfectly plastic constitutive assumptions were adopted for the soil, while the structure was modelled by a three-dimensional anisotropic elastic-perfectly plastic constitutive model, specifically conceived for masonry, accounting for block dimensions and staggering joints effects. 
Finite element approach proves to be very effective in the analysis of such a coupled interaction problem, leading to a realistic representation of the interplay between the soil displacements and their deformative effects within the structure. The numerical results have been interpreted to highlight the structural response in terms of crack pattern and stress distribution as induced by the interaction with the deforming slope, leading to a quantitative evaluation of the landslide-induced damage. Several scenarios were simulated: first, the pre landslide existing crack pattern was reproduced, then the event was modelled as it occurred, evaluating its consequences on the structure.

== Full document ==
<pdf>Media:Draft_Content_479598607p963.pdf</pdf>
== References ==

[1] Puzrin,  A.  M.,  Alonso,  E.  E.  and  Pinyol,  N.  M.  Geomechanics  of  failures.  Springer  Science &amp; Business Media, (2010).   

[2] Canuti P., Margottini C., Fanti R. and Bromhead E.N. Cultural Heritage and Landslides:  Research for Risk Prevention and Conservation. In: Sassa K., Canuti P. (eds) Landslides – Disaster Risk Reduction. Springer, Berlin, Heidelberg (2009).  

[3] ISPRA. Landslides in Italy. Special Report 2008; ISPRA: Roma, Italy, 2008; ISBN 978- 88-448-0355-1.  

[4] Negulescu,  C.,  Ulrich,  T.,  Baills,  A.,  and  Seyedi,  D.  M.  Fragility  curves  for  masonry  structures submitted to permanent ground displacements and earthquakes. Natural hazards (2014) 74(3): 1461-1474.   

[5] Palmisano, F., Vitone, C., and Cotecchia, F. Assessment of landslide damage to buildings  at the urban scale. Journal of Performance of Constructed Facilities (2018) 32(4):04018055.  

[6] Parisi, F., Galasso, C., and Sabella, G. Fragility of reinforced concrete framed structures  to  flow-type  landslides.  In: 12th  International  Conference  on  Applications  of  Statistics and Probability in Civil Engineering (ICASP12) (2015).  

[7] Ferlisi,  S.,  Nicodemo,  G.,  Peduto,  D.,  Negulescu,  C.,  and  Grandjean,  G.Deterministic and probabilistic analyses of the 3D response of masonry buildings to imposed settlement troughs. Georisk:  Assessment  and  Management  of  Risk  for  Engineered  Systems  and  Geohazards, (2019), 1-20.  

[8] Fargnoli, V., Boldini, D., and Amorosi, A. Twin tunnel excavation in coarse grained soils:  observations and numerical back-predictions under free field conditions and in presence of a surface structure. Tunnelling and Underground Space Technology (2015)  49: 454-469.  

[9] Zienkiewicz,  O.C.  and  Taylor,  R.L.  The  finite  element  method.  McGraw  Hill,  Vol.  I.,  (1989), Vol. II, (1991).  

[10] Griffiths, D. V. and Lane, P. A.  Slope stability analysis by finite elements. Geotechnique (1999) 49(3), 387-403.  

[11] Lasciarrea,  W.  G.,  Amorosi,  A.,  Boldini,  D.,  de  Felice,  G.,  and  Malena,  M.  Jointed  Masonry Model: A constitutive law for 3D soil-structure interaction analysis. Engineering Structures (2019), 201: 109803.   

[12] Sangirardi, M., Malena, M., and de Felice, G. (2019) Settlement-induced crack pattern  prediction through the jointed masonry model. In: AIMETA 2019 XXIV conference. The Italian Association of Theoretical and Applied Mechanics, Rome, Italy (2019).  

[13] Castellazzi, G., D’Altri, A. M., de Miranda, S., and Ubertini, F. An innovative numerical  modeling strategy for the structural analysis of historical monumental buildings. Engineering Structures (2017) 132: 229-248.  

[14] Morgenstern, N.U. and Price, V.E. The analysis of the stability of general slip surfaces. Géotechnique (1965) 15(1): 79-93.  

[15] NTC, 2018. Ministero Infrastrutture e Trasporti (MIT). D.M. 17.01.2018. Norme Tecniche per le Costruzioni. Rome, Italy.