PSI - Issue 44

E. Renzi et al. / Procedia Structural Integrity 44 (2023) 355–362 E. Renzi et al./ Structural Integrity Procedia 00 (2022) 000 – 000

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(worse condition). The last three Levels of the GMEB procedure, instead, are more demanding and are focused on achieving an enhanced assessment of the bridges characterized by a higher level of risk: - Level 3 is represented by the Preliminary Evaluation (PE) in terms of ratio between the structural demand for traffic loads derived from the regulation used for the design and the current structural demand for traffic loads (related to Legislative Decree New Italian Construction Standard, 2018); - Level 4 consists of an Accurate Evaluation (AE), much more complex compared to the previous PE, and it is comprised by the execution of the classic calculations and assessments according to all the different verifications contained in the current regulations; - Level 5 is not yet developed in detail but involves an analysis of the resilience of the tracts of the network where the strategic bridges are placed. Considering the OAC condition, the road infrastructure managers optimize the maintenance planning of all the managed bridges and continue to schedule and carry out periodic inspections on bridges. In addition, for bridges with a higher priority the following must be also carried out: extraordinary inspection (more extensive than the periodic ones) and PE, for bridges with Medium or High/medium OAC; continued monitoring (Structural Health Monitoring for certain bridge typology), for bridges with High/medium or High OAC; AE, for bridges with High OAC. 3. The Need to apply the GMEB procedure within an Integrated Risk Management System After the description of the main characteristics of the GMEB procedure, it is useful to underline the most significant aspects to take into account (due to their influence on the definition of safety levels), by road managers, to define integrated Management Systems, aimed at properly managing road infrastructures by integrating all the aspects that play an important role for the road infrastructures’ safety. In particular, it is important to consider, in a systemic way, the following (relevant) activities: - Inspection scheduling; - OAC determination, evaluations planning and relative outcomes; - Adoption of mitigation measures (e.g. the aforesaid restrictions/limitations); - Scheduling/execution of maintenance interventions, the relative use limitations for the structures, and the impact that its executions can have on the network safety performance; - Monitoring activities (such as the periodic/continuous structural monitoring or the traffic loads monitoring) and possibly related actions. In addition, it is crucial perform the management of the viability and of the communications that derive from the activities concerning the GMEB procedure application (e.g. the rearrangement of the viability in consequence of the restrictions/limitations adopted for a transitable bridge). The results of the assessments conducted based on the GMEB Guidelines must be framed within Integrated Management Systems to pursue the optimal operational and financial planification of interventions, to be carried out for the safety performance maximization of the existing bridges located along a well-defined road network. The resulting integration can be done by applying the Safety Management System (SMS) described in the next paragraph. Considering the complexity and the amount of data, it is important that: - the procedures (such as the one contained in the GMEB) must be part of an Integrated Risk Management System; - the completeness, uniformity and consistence of information provided by the GMEB procedure is essential for the correct definition of the priorities and the planification of the more suitable intervention, aimed at mitigating the seismic risk. In particular, the activities aimed at the detection of the aspects related to the seismic vulnerability, together with the "boundary conditions" (geological and hydraulic), as well as with the aspects related to hazard and exposure, which classify the seismic risk, must certainly be considered in the key processes implemented in the Management