Preventive planning model for rescue priority management in seismic emergency

Natural materials, such as soils, are influenced by many factors acting during their formative and evolutionary process: atmospheric agents, erosion and transport phenomena, sedimentation conditions that give soil properties a non-reducible randomness by using sophisticated survey techniques and technologies. This character is reflected not only in spatial variability of properties which differs from point to point, but also in multivariate correlation as a function of reciprocal distance. Cognitive enrichment, offered by the response of soils associated with their intrinsic spatial variability, implies an increase in the evaluative capacity of the contributing causes and potential effects in failure phenomena. Stability analysis of natural slopes is well suited to stochastic treatment of uncertainty which characterized landslide risk. In particular, this study has been applied through a back- analysis procedure to a slope located in Southern Italy that was subject to repeated phenomena of hydrogeological instability (extended for several kilometres in recent years). The back-analysis has been carried out by applying spatial analysis to the controlling factors as well as quantifying the hydrogeological hazard through unbiased estimators. A natural phenomenon, defined as stochastic process characterized by mutually interacting spatial variables, has led to identify the most critical areas, giving reliability to the scenarios and improving the forecasting content. Moreover, the phenomenological characterization allows the optimization of the risk levels to the wide territory involved, supporting decision-making process for intervention priorities as well as the effective allocation of the available resources in social, environmental and economic contexts

Juridical Side of ALARP: The Monte Bianco Tunnel

When the ALARP “as low as reasonably practicable” principle is considered in judgments, this always comprehends a proportionate cost-risk analysis of protection measures: minimum risk has to mean level of safety maximization conditional to a given equitable profit, and maximum profit given a minimum sufficient level of safety. In London Court in 1949, Lord Asquith's definition of “reasonably practicable” in its judgment “Edwards v. National Coal Board”, as well as the whole judgment, became the legal basis of a requirement for risk assessments. Since then, ALARP has been officially endorsed and safety measures implemented in governments and enterprises in order to mitigate and manage risks. The study aims to analyse the failures in the Monte Bianco tunnel’s accident – which occurred on March 24, 1999 – from a logical perspective in order to develop a higher level of safety based on past experience and that played a central role in generating the current European Directive 2004/54/EC on minimum safety requirements for tunnels. This article reveals the consequences of ignoring the value of ALARP principle. Error analysis in Forensic Engineering are discussed and Gu@larp model contribution is considered

ALARP in engineering. Risk based design and CBA

It has not been far, over a century, since humankind conceived that hazardous incidents should be substantially managed to procrastinate the future could-be hazards. In the middle of the twentieth century, nonetheless, safety measures were passed by officials and introduced to authorities, and private sectors, so as to reduce risks, environmental impacts of the hazards and to evaluate probable outcomes. Therefore, the concept of ALARP, meaning ‘as low as reasonably practicable’ presented back then, has been implemented in risk reduction management to make decisions upon acceptability and tolerability of risks. In order to do so, a few so-called tools, such as Cost-Benefit Analysis, are specified to societal and other types of risks so that we could weigh the balance of the amount of capital to be invested on safety on the one hand, and the extracted benefit attained out of the investment on the other. This implementation opaquely carries on several social, socio-economic, political a nd even environmental implications. Nevertheless, it has brought up some concerns into proponents’ mindset, ranging from practicality and political reality to calling into question whether ALARP is mainly theoretical. The aim of this study is to figure out whether Cost-Benefit Analysis can be an appropriate tool to analyse the true outcome(s) of ALARP. This paper will offer a critical point of view over the risk-evaluating concept to discern how much it has been practically efficient

Semi-Supervised Discovery of DNN-Based Outcome Predictors from Scarcely-Labeled Process Logs

Predicting the final outcome of an ongoing process instance is a key problem in many real-life contexts. This problem has been addressed mainly by discovering a prediction model by using traditional machine learning methods and, more recently, deep learning methods, exploiting the supervision coming from outcome-class labels associated with historical log traces. However, a supervised learning strategy is unsuitable for important application scenarios where the outcome labels are known only for a small fraction of log traces. In order to address these challenging scenarios, a semi-supervised learning approach is proposed here, which leverages a multi-target DNN model supporting both outcome prediction and the additional auxiliary task of next-activity prediction. The latter task helps the DNN model avoid spurious trace embeddings and overfitting behaviors. In extensive experimentation, this approach is shown to outperform both fully-supervised and semi-supervised discovery methods using similar DNN architectures across different real-life datasets and label-scarce settings

Geostatistical modeling of seismic actions on the structural components of the San Benedetto road tunnel, Italy

The Italian legislation requires determining the project seismic actions and to carry out the dynamic stability verification of the structural elements of a building or road infrastructure on the base of the seismic hazard curve of the construction site. The geographic density of the available seismic data requires the best use of existing data and above all not introducing phenomenological assumptions and unverified information into the survey. This article proposes an investigation protocol that integrates the multivariate statistical analysis methodologies already used to determine the seismic shaking attenuation with more efficient and versatile geostatistical methodologies for a more realistic estimate of non-stationary parameters. The application of the new investigation protocol to the earthquakes that occurred in Italy in 2016 made it possible to detect and resolve three fundamental aspects of seismic modeling: (i) the recorded data highlight the presence of a directional anisotropy of the arrival time and the value of the acceleration peak on the ground which led to the introduction of a non-Euclidean metric in seismic modeling; (ii) the presence and measurement of the geographical continuity of the irregular variations between data pairs attributable to the heterogeneity of the rock formations and outcropping soils; (iii) the need for an experimental measure of the estimate uncertainty for an objective evaluation of the applied numerical estimator. This last result made it possible to evaluate the gain in terms of accuracy of the estimate performed with the local geostatistical estimator. The article presents the estimate of the arrival time and the peak value of the vertical (PGAV) and maximum horizontal (PGAH) component of the acceleration of the vibrational movements of the rock around the San Benedetto tunnel during the Norcia earthquake. The maximum estimated values of PGAV and PGAH are around the section of the tunnel damaged by the earthquake

Risk based tunnel design by vehicle involved in road crashes. Models and tunnel length

Between 2018 and 2020, in the approximately 2,600 km of Italian road tunnels, 2,899 people were injured and 60 died in 1,885 road accidents. The accident frequency was lower than on open roads, while the injury/fatality rate was higher. Using the recursive partitioning and regression trees method (rpart), we developed two accident models useful for predicting the probability of involvement of "vehicle type" in short and long tunnels. Variables such as the type of accident, the circumstances, the type of road, the carriageway, the time of the accident, the journey purpose (whether work-related or not), and the length of the tunnel defined the nodes and paths of the regression tree associated with a vehicle type involved. The “road type” was the best predictors for short tunnels while the “journey purpose” was the best predictor for long tunnels. The most important result of the study refers to the similarity between the probability of an accident in short and long tunnels for a specific segment of road users: commuting and non-commuting car drivers and drivers of heavy goods vehicles on-duty. The study showed that this road user segment in short tunnels has an accident probability half that observed in long tunnels

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

Road tunnel risk-based safety design methodology by GU@LARP Quantum risk model

The ALARP concept is used in different countries for different sectors of activity where a risk assessment or measure is requested. In this paper a model is developed based upon ALARP principle for tunnel risk-based design in case of fire accident scenarios. In Italy, ALARP risk acceptability and tolerability criteria have been adopted then the compliance with them has to be verified in order to guarantee a minimum-sufficient level of safety. The quantum of risk coupled with any design scenario is defined and modelled and the consequent individual quantum of risk coupled with the single exposed unit in the scenario is defined too. The methodologies for the identification of the requested design scenario, in number and type, are outlined. The scenarios are described in a shape suitable as INPUTS in the thermo-dynamical numerical simulations for fire generation and exposed units evacuation. The expected OUTPUTS of the numerical simulation are the estimations of the number of the fatalities (N) coupled with the single specific scenarios. In parallel with the above physical deterministic scenario simulations, a conceptual and operational procedure has been also established for the scenarios probabilities assessment. Merging the resulting data of both the above separate models, the risk quanta Gu@larp model is finally established. A case study is developed considering scenarios related to a virtual limit tunnel to support the description of the model itself, properties, advantages and perspectives

USE OF SHERPA FOR THE PREVENTION OF HUMAN ERRORS AMONG AGRICULTURAL MACHINERY USERS

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