Contribution of engineering geology for the construction of a new museum gallery over an archaeological site at Lorvão Monastery, Portugal

The rehabilitation of the Lorvão Monastery in Penacova, Portugal, included the construction of a new steel structure to house a museum gallery. The implementation of an archaeological excavation prior to construction revealed a mesh of ancient masonry walls, dating from the 16th to the 18th centuries, which needed to be preserved and made available for exhibition. To help understand the characteristics of this foundation ground, an engineering geology study was required, strongly conditioned by the presence of heritage, reduced space and difficult accessibility caused by the extensive temporary support used to ensure stability of the walls. The engineering geology study consisted of a detailed surface mapping, complemented by non-destructive in situ tests, the soil stiffness gauge (SSG) and the surface moisture-density gauge (SMDG) and by the use of the Bieniawski rock mass rating (RMR) geomechanical classification. Three geotechnical zones were defined. The non-invasive engineering geology study performed proved suitable to provide the geotechnical information necessary to redesign and construct the steel structure over a challenging archaeological site, preserving the heritage.