PSI - Issue 44

Iolanda Nuzzo et al. / Procedia Structural Integrity 44 (2023) 1832–1839 Iolanda Nuzzo et al./ Structural Integrity Procedia 00 (2022) 000–000

1834

7

of mitigation actions (MA) to provide a number of mitigation strategies (MS) each for a given scenario, just few seconds after the identification of an earthquake, with the final aim of minimizing the loss costs induced by seismic event. The system is specifically developed for railway bridges. The attainment of alarm thresholds, each generating a specific mitigation strategy, are detected by a monitoring system installed on the infrastructure itself. The RRSW is opportunely calibrated for the infrastructure to be protected according to the methodology illustrated in Fig. 1 and described in the following sub-sections.

2. Mitigation Strategies (MS) 4. Monitoring System

1. Context Analysis

3. Structural Analysis

5. Loss Analysis

6. Optimal MS

Fig. 1. Railway Rapid Seismic Warning (RRWS) for seismic risk mitigation of rail infrastructure.

Fig. 2. EAV Viaduct - Plan View and crossing roads at the ground level.

2.1 Step 1: Features of the railway infrastructure and context analysis The analysis of the surrounding context where a reference structure is located is a critical factor in seismic risk management directly resulting in risk exposure. In addition, the presence of facilities like urban factories, schools and airports in the vicinity of the infrastructure is relevant for the definition of the suitable MA to be launched. Particularly, the viaduct EAV (Ente Autonomo Volturno) belongs to the circumflegrea railway line, which spans over Montesanto Soccavo-Quarto-Torregaveta locations in the metropolitan area of Naples, as shown in Fig. 2. The plan view of the viaduct can be separated in two sections (i.e. Section A and Section B, see Fig. 2), and it is worthy to mention that the present study is focused on Section A which represents most of the viaduct length. 2.2 Step 2: Definition of the alternative mitigation actions and strategies Once the key features of the railway network and its relative context are known, it is necessary to define the most appropriate MAs to be undertaken in order to reduce the impact that an undesired seismic event may have on the safety of people and property. These MAs can be related to pedestrian flows, transportation services, production lines, among others. Given that the EAV viaduct has a certain distance from other critical areas (e.g. airports, plants, schools) the mitigation actions considered in this case study mainly focus on train service and functionality of external roads crossing the viaduct path at the ground level. Particularly, the viaduct crosses two roads, one of them in the proximity