Recognition and strength characterization of platy limestone layers in the Classical Karst quarries (NE Italy)

This paper shows the results of research investigations carried out along the karst plateau located in the Trieste and Gorizia counties (NE Italy), with special emphasis on limestone quarries. Field surveys allowed the recognition, identification and mapping of quarries characterized by the presence of Platy Limestone (PL). The latter is characterized by a single discontinuity set with spacing not exceeding 10 cm. For this reason, the geometry of PL rock masses provided, for a long time, slabs easy to be excavated. PL was widely used by locals for roofs of buildings situated mainly in the rural surroundings of Trieste. The research envisaged a multidisciplinary approach, which also included the definition of the main geometrical features of PL quarries, the state of activity and the geotechnical properties of PL rock mass. Particular attention was devoted to the definition of PL intact rock strength, which is major rock property. Intact rock strength determines the strength of the rock slab and therefore its geomechanical quality. The outputs of this paper can motivate local authority to protect PL and promote its use for the restoration of historical buildings.