Massimo Guarascio

Assessment of a vulnerability model against post-earthquake damage data: the case study of the historic city centre of L'Aquila in Italy

The quantitative measure of seismic vulnerability is a necessary requirement for prevention and for an optimal emergency management. Before L’Aquila’s earthquake in 2009, the National Civil Protection, in collaboration with the University of L’Aquila, developed a model (Beolchini, “Definition of an indicator of urban vulnerability” (2003)) to evaluate the criticality seismic of urban centers by using a multidisciplinary approach. The study has led to the definition of an urban vulnerability index, that allows to identify the most critical urban centers and the problematic elements, in order to establish a hierarchy for preventative measures and for an efficient emergency management (Calvi et al. “Development of seismic vulnerability assessment

Geostatistics/reliability based risk analysis of the Vajont landslide

This paper is devoted to the probabilistic analysis of the Vajont landslide event according to the basic statements of risk analysis. In particular, the goal is to find out a regressive estimate of the landslide rate of movement in terms of the rainfall, Rf, and the reservoir level, Rl, time evolution during the test period. This will be obtained by developing a kind of geostatistical analysis on the space of standardized variables (Rf ,R l), based on classical ordinary kriging. Risk analysis will be formulated introducing a suitable safety margin function, depending on the mass of the slide, M, on its initial velocity, vin, and the amplitude, H ,o f the water wave flowing out of the Vajont basin.

Risk Analysis and Reliability Based Design in Tunnel Fire Safety

This paper describes a quantitative risk analysis procedure that deals with 2 specific aspects of fire safety design in road and rail tunnels: the smoke control system effectiveness; and the spalling effect and structural reliability of the liners.

Risk analysis and reliability of the GERDA Experiment extraction and ventilation plant at Gran Sasso mountain underground laboratory of Italian National Institute for Nuclear Physics

The aim of this study is the risk analysis evaluation about argon release from the GERDA experiment in the Gran Sasso underground National Laboratories (LNGS) of the Italian National Institute for Nuclear Physics (INFN). The GERDA apparatus, located in Hall A of the LNGS, is a facility with germanium detectors located in a wide tank filled with about 70 m3 of cold liquefied argon. This cryo-tank sits in another water-filled tank (700 m3) at atmospheric pressure. In such cryogenic processes, the main cause of an accidental scenario is lacking insulation of the cryo-tank. A preliminary HazOp analysis has been carried out on the whole system. The risk assessment identified two possible top-events: explosion due to a Rapid Phase Transition RPT and argon runaway evaporation. Risk analysis highlighted a higher probability of occurrence of the latter top event. To avoid emission in Hall A, the HazOp, Fault Tree and Event tree analyses of the cryogenic gas extraction and ventilation plant have been made. The failures related to the ventilation system are the main cause responsible for the occurrence. To improve the system reliability some corrective actions were proposed: the use of UPS and the upgrade of damper opening devices. Furthermore, the Human Reliability Analysis identified some operating and management improvements: action procedure optimization, alert warnings and staff training. The proposed model integrates the existing analysis techniques by applying the results to an atypical work environment and there are useful suggestions for improving the system reliability.