LAUSR

Abstract. The stability of man-made underground cavities in soft rocks interacting with overlying structures and infrastructures represents a challenging problem to be faced. Based upon the results of a large number of parametric two-dimensional (2D) finite-element analyses of ideal cases of underground cavities, accounting for the variability of cave geometrical features and rock mechanical properties, specific charts have been recently proposed in the literature to assess at a preliminary stage the stability of the cavities. The purpose of the present paper is to validate the efficacy of the stability charts by means of the application to several case studies of underground cavities, either subjected to collapse in the past or still stable. The stability charts proposed result to be performing to catch the stability conditions and, eventually, the conditions that lead to failure occurrence. For sinkholes already occurred, they show the importance of structural elements as pillars and internal walls in the stability of the whole quarry system, whereas, for cavities that have not reached failure, they can provide useful indications about the eventual proneness of the underground cavity to local or general instability phenomena.