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

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

Assessing Risk Acceptability and Tolerability in Italian Tunnels with the Quantum Gu@larp Model

Road tunnels are associated with numerous risks including traffic accidents and fires, posing threats to individual or group users. Key risk indicators such as Risk Quantum, Individual Risk, Societal Risk, and Expected Number of Fatalities are instrumental in evaluating the level of risk exposure. These indicators empower Rights-Holders and Duty-Holders to report hazards, prevent disasters, and implement timely remedial measures. A crucial indicator, the Scenario Risk Quantum, has its roots in the forensic evaluation of responsibility in a fatal tunnel accident in the UK since 1949. The Quantum of Risk of each design scenario, reasonably selected among rational and practicable possibilities, has both a deterministic and probabilistic character. The Risk Tolerability and Acceptability criteria are modelled according to risk indicators by selecting the parameters according to ethical principles and societal policy. Scenarios are meticulously identified, described, probabilised and assigned probabilities prior to the quantitative risk analysis. These risk indicators are integral to the risk assessment process. This article delves into the understanding of these indicators within the context of Italian road tunnels, employing the Quantum Gu@larp Model to analyse Risk Acceptability and Tolerability

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

Safety Level Measure and Risk Assessment in Multi-Hazard Scenarios within Underground Systems

This seminar offers a comparative study on safety level measures and risk assessment in multi-hazard scenarios within tunnel systems, focusing on the CERN underground infrastructure and motorway tunnels. It provides an in-depth understanding of basic concepts, applied methodologies, fire and radiation exposure scenarios, and multi-hazard scenarios, followed by an interactive summary and discussion session