PSI - Issue 44

Manuel Capogna et al. / Procedia Structural Integrity 44 (2023) 705–712 Manuel Capogna et al./ Structural Integrity Procedia 00 (2022) 000–000

710

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Obviously, the former has a lower level of vulnerability than the latter: this consideration leads to a correction of the classification made on the basis of static scheme, light and material according to the logical flow. If the analysis of the available documentation does not allow to trace the information necessary for the evaluation of the design criteria adopted, the bridge is considered as designed with "non-seismic" criteria, to proceed in favor of safety. The level of defects and, therefore, the state of conservation of the bridge is estimated by processing the data collected from the Level 1 visual inspections, focusing on the elements and construction details that are particularly influential on the global seismic behavior of the building. These are therefore piles, foundation structures, support devices. The data processing leads to the distinction of 5 levels of defects, defined with criteria similar to those used to determine the structural and foundational vulnerability class, but related to the seismic behavior of the structures. of the bridge are obtained from the defect cards proposed in Annex B of the Bridge Guidelines. 3.3. Calculation of level of structural and foundational exposure The estimate of the level of exposure is based on traffic data relating to the road network of interest, in terms of the frequency of passing vehicles, as well as on factors related to the ability of the network to cope with unforeseen situations, i.e. its resilience. The parameters to be considered for the assessment of the exposure factor are: • primary parameters: Average Daily Traffic Level (ADT) and span length; • secondary parameters: Road alternatives, type of body bypassed, transport of dangerous goods. Similarly to the other factors, the value of the primary parameters determines a distinction into 5 classes or levels of exposure which is then modified by the value of the secondary parameters. In this case, the parameter linked to the transport of dangerous goods affects the final classification of the class of attention, in order to establish an order of priority between works belonging to the same class. 3.4. Calculation of level of seismic exposure The roadworks considered to be of strategic interest, whose functionality during seismic events assumes fundamental importance for the purposes of civil protection, must have a higher priority, as it is necessary to ensure their efficiency in the event of an emergency.

3 Determination of Seismic Exposure

Medium span lenght

Average Veicles/Day

m Medium span lenght

34

Medium

msl>=50m

High

avd>=25000

High

v/day Average Veicles/Day

10000

20m<=msl<50m Medium

10000m<=avd<25000 Medium

Medium

msl<20m

Low

avd<10000

Low

Medium span lenght, Daily average traffic M-L

Road alternatives Yes Not

Road alternatives

Yes

Road alternatives

M-L

Administration crossed High Medium Low

Administration crossed

High

Structural and foundational exposure M

Strategic nature of the bridge Strategic Not strategic

Strategic nature of the bridge

Strategic

Seismical Exposure AC M-H

Fig. 5. Determination of Seismic Exposure.