Mara Lombardi

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.

Hazard function deployment: a QFD-based tool for the assessment of working tasks – a practical study in the construction industry

Despite the efforts made, the number of accidents has not significantly decreased in the construction industry. The main reasons can be found in the peculiarities of working activities in this sector, where hazard analysis and safety management are more difficult than in other industries. To deal with these problems, a comprehensive approach for hazard analysis is needed, focusing on the activities in which a working task is articulated since they are characterized by different types of hazards and thus risk levels. The study proposes a methodology that integrates quality function deployment (QFD) and analytic network process methods to correlate working activities, hazardous events and possible consequences. This provides more effective decision-making, while reducing the ambiguity of the qualitative assessment criteria. The results achieved can augment knowledge on the usability of QFD in safety research, providing a basis for its application for further studies.

Reliability Analysis for Preliminary Forecasts of Hydrogeological Unit Productivity

The aim of this work is to find a probabilistic characterization of the productive capacity of a well in a geological formation hosting an aquifer. Such characterization in terms of productive capacity may allow a preliminary assessment to be made of the probability of success for a required productivity (i.e. target point). This evaluation is usually carried out by statistical analysis of a geological dataset, which is likely to be influenced by many parameters. Such datasets are often incomplete or unreliable. Therefore, a method for evaluating potential productivity, using probabilistic hydraulic conductivity data, is proposed. The hydraulic characterization of hydrogeologic units is based on the collection of information obtained mainly through pumping tests and their interpretation. The results, expressed in terms of hydraulic conductivity, are summarized in a range of variability that is strictly dependent on the number of performed tests and their spatial distribution in the unit itself. If this range is known, an estimate of well’s yield can be made on a deterministic basis, through Thiem’s relationship for steady state conditions, by setting a value of hydraulic conductivity that corresponds to the average value of the range. The proposed reliability analysis enables to overcome the limitations of the deterministic approach by correlating each calculated flow rate, which is taken to be a design flow rate exceeding the critical flow rate of the hydrogeologic unit, to its probability of failure. Therefore, this approach aims to evaluate the probability of failure of the water system. The preliminary result is to associate the values of aquifer exploitation with a probability failure function. This outcome can then be used to define the potential solutions in the optimal allocation of the withdrawal by means of reliability analysis that takes into account the uncertainty of the system.

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.

THE ROLE OF BIM FOR SAFETY AND SECURITY MANAGEMENT

A vital component of any type of organization for the prevention of incidental events and/or voluntary attacks against people and tangible and intangible assets as well as for their protection when incidental events and/or voluntary attacks happen is represented by safety and security management. Because of the incessant development of new dangers and threats, safety and security management requests unceasing updating, by means of powerful and flexible tools, such as BIM, which must be integrated via a multidisciplinary approach, considering also economic features that must optimized from the cost/benefit point of view. Integrated technological systems represent efficient tools to create solutions than can support safety and security management in a competent manner, considering also budgets optimization. For this reason, it is necessary to utilize a wide-range approach which, thanks to its flexibility, allows for the realization of an integrated multidisciplinary model for safety and security management (IMMSSM) which can be supported by a suitable Integrated Technological System Framework (ITSF), even based on Internet of Everything (IoE). To achieve an operative IMMSSM, it is necessary to optimize the available tools from the cost/benefit point of view. This goal represents a difficult challenge because, in general, restricted funds are available. From this point of view, efficient and flexible tools, such as BIM, represent vital elements to obtain solutions characterized by an optimal cost/benefit ratio. The purpose of this paper is to illustrate the role of BIM for safety and security management, showing its peculiar features from this point of view and its versatility both for the realization of resourceful IMMSSM and related ITSF, even based on IoE.

Consistency and stability of risk indicators: the case of road infrastructures

Over the last decade, the World Road Association – PIARC and several European research projects, among which Ecoroads, have encouraged a promising reflection on risk analysis methods, acceptance criteria and safety practices applied to the road system. The goal of this research activity is the definition of best practice for safety analysis and management to be applied to network TERN (Trans European Road Network). Quantitative Risk Analysis (QRA) provides much information on safety management. Nevertheless, the potential fragility of the method, stochastic uncertainties (both parameters and models), and ethical aspect of criteria must be adequately analyzed. This paper focuses on all these aspects, assessing the reliability of QRA due to modeling errors and statistical errors, and assessing the statistical consistency of Risk Indicators of QRA.

Fire Protection Of Emergency Electrical Devices: Effect On The Level Of Risk – A Case Study Of A Rail Tunnel

In rail and road tunnels the occurrence of fire is the most dangerous scenario in terms of resulting emergencies [1]. Therefore, the best practice and current regulations require measures and devices for prevention and protection, designed to reduce the probability of occurrence of fire (critical scenario) in tunnel and to control the effects in case of its occurrence [2]. Safety and Security Engineering VI 73

ITALIAN HYBRID FIRE PREVENTION CODE

Fire safety of residential buildings and activities subjected to fire inspection are difficult tasks, especially when the safety targets have to be adopted in pre-existing buildings or in activities that are going to be modified into more complex ones. Generally, these circumstances show more constraints and it can be difficult to achieve an acceptable level of fire residual risk by prescriptive based fire regulations. Therefore, the Italian National Fire Rescue and Service in charge of fire safety, in August 2015, issued a new Fire Prevention Code whose design methodology is more oriented to fire performance based design rather than prescriptive fire codes. The flexibility of this new fire design methodology offers a very complex tool for experts in order to design fire safety measures and strategies for buildings and activities subjected to fire inspection. The present paper aims to highlight the contents and the fire safety strategy design methodology of the new Italian Fire Prevention Code.

An integrated internet of everything — Genetic algorithms controller — Artificial neural networks framework for security/safety systems management and support

Security/Safety is managed, mostly, by means of integrated systems which have to consider, more and more, sensors, devices, cameras, mobile terminals, wearable devices, etc. that use wireless networks, to ensure protection of people and/or tangible/intangible assets from voluntary attacks, allowing also the safe management of the related consequent emergency situations that can derive from the above mentioned voluntary attacks. These aims can be achieved using integrated systems and innovative technologies, such as Internet of Everything (IoE) which can connect people, things (mobile terminals, smart sensors, devices, actuators; wearable devices; etc.), data/information/knowledge and particular processes. An integrated security system can therefore be considered as an IoE system where several devices, sensors, cameras, people, etc. interact, generating a huge volume of data and information that is necessary to transmit, analyze and eventually store for security purposes and, ultimately, for emergency management derived from voluntary attacks. This means that it is necessary to use suitable tools capable of analyzing, in a smart way, the huge volume of information to achieve the desired security/safety objectives and eventual emergency management of critical situations. The purpose of the paper is to illustrate an integrated IoE-GACs-ANNs based framework which can support and manage security/safety systems that operate in complex environments, characterized by a multitude of sensors, devices, etc. and the related results obtained from theoretical, computational and practical point of view, where it has been applied.

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.