Geological analysis and stability assessment of a sea arch in Palinuro, southern Italy

The study aims to describe the geological and geostructural layouts of an unstable sea arch located in a very attractive tourist area of Southern Italy. On the basis of ad hoc field surveys and laboratory tests, the problems of an in-depth geo-mechanical characterization of the rock mass are discussed in details and its main strength parameters are derived. An indirect assessment of the possible geostati stress field due to the neotectonic events, which affected this sector of Apennine Range during the last 100,000 years, is proposed and validated by means of numerical non-linear FE analyses. The results suggest that the presence of a lateral thrust acting into the promontory located at the back of the arch, is very likely and its effects would agree well with the failures occurred in the past on the arch surfaces. It is concluded that any possible intervention should be carefully designed on the basis of the highlighted factors and further investigations.