Risultati inclinometrici ed indagini geologico-stratigrafiche nel centro storico di Maratea (Basilicata)

Inclinometric result and geological investigation at Maratea heritage (Basilicata, Italy)

Abstract

The results of inclinometric research carried out on 4 probes located near the main-church of Maratea over a relatively long period of time (1992-1995/96) are presented and discussed in this paper. These results have been linked to observations made of the damage sustained by the buildings in the same area during this period and to the local strati-graphic, geomorphological and hydrogeological data. The historical town centre of Maratea is built on debris and large landslide blocks, resting at a maximum depth of 40-60 m on a grey clayey flysch with a contact water table. The data on deep movement, collected regularly since 1994 using inclinometric soundings, are particularly significant in the cases of probes 3 and 4, where they intercept a sliding surface at the base of the unstable material at depths of 25 an 33 metres respectively. The gravitational movements show reasonably uniform velocity (0.9 mm per month) and, appear to be uninfluenced by rainfall, whereas the water-levels oscillate within 2-3 metres at most. The detected movement directions show the same orientation towards the steepest slope, denoting a sliding of more ample proportions than that originally hypothised. From an observation of data existing on building deformation in the area it would appear that there has been an acceleration of movement here since 1986, although this acceleration is not clearly evident from the results of the inclinometric soundings alone, due perhaps to the scarcity of relative data before 1994.