Predictable Models in Earthquake Engineering and in Materials Durability

The decay process of a "system" subjected to the action of an aggressive enviranment is studied with reference to two particases: porous materials subjected to salt decay in marine and industriai areas and buildings in seismic areas. A service life time is defined in relation to every significant damage level of the system. On the basis of experimental analysis and knowledge of physical failure mechanisms, Semi-Marbv Processes are introduced to represent decay phenomena. In this hypothesis the suitable choice of holding time densities is discussed. As far as seismic building damage is concenied, the influence of a seismic inteasity attenuation- law on the process of earthquake occurrence is studied, with particular reference to the case of Friuli. The role played, in the stochastic model, by geometrical distributian of seismic sources and by building vulnerability is put forward. The problem of mitigation risk intervention is considered and some results of experimental analysis on porous materials are shown.