Building risk assessment methodology for explosive and non-conventional terrorist attacks

Eur. Phys. J. Plus (2024) 139:669 https://doi.org/10.1140/epjp/s13360-024-05422-6 Regular Article Building risk assessment methodology for explosive and non-conventional terrorist attacks Marco Carbonelli1 , Riccardo Quaranta5,2,a Andrea Malizia3 , Laura Gratta6 , Pasquale Gaudio2 , Daniele Di Giovanni2,4 , Grace P. Xerri2 , 1 2 3 4 Presidency of the Council of Ministers, Rome, Italy Department of Industrial Engineering, University of Rome Tor Vergata, Rome, Italy Department of Biomedicine and Prevention, University of Rome Tor Vergata, Rome, Italy Unicamillus-Saint Camillus International University of Health Sciences, Rome, Italy 5 The American University of Rome, Rome, Italy 6 Italian Risk Management Expert, Rome, Italy Received: 26 March 2024 / Accepted: 2 July 2024 © The Author(s) 2024 Abstract An original methodology suitable for the assessment of the risk of a terrorist attack in a given site/building is proposed and illustrated for the case of an explosive or non-conventional (Chemical, Biological, Radiological, Nuclear and explosive—CBRNe) attack. The Building Risk Assessment Methodology discussed in this paper represents the arrival point of a detailed analysis and research carried out during the past 5 years and provides the synthesis of different results obtained for the assessment of Building Threats and Building Vulnerabilities. These two assessments were discussed in detail in other already published papers. The effort presented in this work is to deploy a risk and impact assessment technique for buildings that can be adopted in any operating scenario in the presence of explosive or non-conventional threats. The main target of the methodology is to provide a sufficiently accurate estimate of the risk in a simple fashion. The methodology allows to manage the different kinds of risk related to the explosive and non-conventional threats, and it is useful for identifying a ranking of risks for different buildings in different portions of territory and for prioritizing actions and investments in preparedness, protection and resilience of critical areas and critical infrastructures. In the paper, the results of two different case studies for three different threats will be considered, analyzed and compared. 1 Introduction Risk assessment is a widely discussed and implemented methodology across various fields of human activities, spanning, for example, from finance to civil protection and personal data protection. One critical area where risk assessment techniques are vital is the protection of buildings, particularly in reference to terrorist attack scenarios. The events of September 11, 2001, i.e., the attacks to the New York World Trade Center and to the Pentagon also known as 9/11, have significantly increased awareness and stimulated extensive attention to this issue over the past decades. As highlighted by many scholars, this event and its profound impacts and consequences have marked a key shift in the approach of terrorist threats against buildings [1], raising the attention of both the general public and the specialists in this field. Recent trends in terrorist activities show this shift from targeting exclusively institutional or high-value buildings to an increased frequency of attacks on more accessible targets. In fact, prior to 9/11, terrorist actions were typically logistically complex, often involving hostage situations or mass casualties at high-value sites. However, following the 9/11 events, terrorist strategies evolved toward easier-to-execute attacks, although the lethality of such incidents remains significantly high [2]. It is evident that buildings have begun the preferred targets for terrorists, as they serve as central hubs of a country’s economic activity and symbolize its wealth and culture. Thus, safeguarding buildings from terrorist attacks has become a crucial element of the defense strategy adopted by Western countries. This strategy entails a comprehensive approach to building risk assessment, aiming to mitigate vulnerabilities and introduce technical methods and measures fitted for building protection design with the objective of protecting both individuals and properties by enhancing the security of the site’s exterior, the building perimeter and its internal functions. In this paper, a well-established approach to building risk assessment [3] is used, recalling the two foundational methods outlined by the authors in the previous published works: the Building Threat Assessment Method (BTAM) [4] and the Building Vulnerability Assessment Method (BVAM) [5]. Additionally, a method for conducting a Building Exposure Assessment Method (BEAM) is a e-mail: (corresponding author) 0123456789().: V,-vol 123 669 Page 2 of 12 Table 1 Characterization of the threats for the considered attacks Eur. Phys. J. Plus Parameter (2024) 139:669 Type of attack Explosion of a van bomb Explosion of a suicide belt bomb Explosion of a Cesium-137 dirty bomb Type of material or explosive employed TNT TNT TNT and Cesium-137 Type of vector Van Belt bomb Pick-up truck Maximum amount of the material employed 800 kg 5 kg 400-kg TNT and 90-g Cesium-137 Specific location relative to the structure suitable for the application of the threat Area of entry for shipping/delivery vehicles Access part of the building, corresponding to the main entrance External main parking area of the building introduced. These three methods are integrated into a comprehensive Building Risk Assessment Methodology (BRAM), which is then applied to two case studies involving different building typologies. To conduct a complete building risk assessment, the application of this methodology should be assigned to a specialized Assessment Team (AT) [4, 5]. This team should consist of engineers, architects and subject matter experts with the expertise to conduct an accurate analysis of Chemical, Biological, Radiological, Nuclear and explosive (CBRNe) threats. Additionally, the involvement of intelligence experts and direct access to intelligence information could be crucial for accurately estimating the final risk levels, beginning with the assessment of threats, vulnerabilities and exposure levels. 2 Case studies This study examines three threats proposed in a previous paper of the authors [4]. These threats include the detonation of a suicide belt bomb, the detonation of a van bomb and the detonation of a Cesium-137 Radiation Dispersal Device (RDD), commonly called dirty bomb. This approach follows a similar methodology described in [4, 5], providing a concrete basis for the analysis. For each selected threat, the AT specified the parameters below: • • • • Type of material or explosive employed, Type of vector for the material or explosive employed, Possible maximum amount of the material employed, Possible specific location relative to the structure suitable for the application of the threat. In this paper, the scenarios will be evaluated assuming t (...truncated)