Safety reassessment of multiple arch dams in Italy: General considerations and presentation of a case-study

摘要

The tradition of Italy in the dam field, in the modern age, starts at the beginning of 1900. Among the first structures built in the country, the typology of multiple arch dams occupies a significant position in particular for the link with the parallel evolution of the reinforced concrete production at the beginning of the last century. In general, these dams have been built using reinforced concrete for the multiple arches and reinforced concrete and masonry for the buttresses. The problems that the dam engineer has to cope with in the safety reassessment are in general the following: (a) insufficiency of the capacity of outlets due to the limited availability of hydrological data at the design stage; (b) ageing and deterioration of the materials due to environmental conditions and possible chemical-physical phenomena; (c) limited strength of the structures with reference to seismic loads not considered at the design stage; (d) problems related to the fulfillment of the present Italian Standards which have been updated several times. In the paper, after the presentation of some general aspects related to multiple arch dams and to safety reassessment problems, the case-study of Molato dam is presented.