PSI - Issue 44

Franco Braga et al. / Procedia Structural Integrity 44 (2023) 331–338 Franco Braga et al. / Structural Integrity Procedia 00 (2022) 000–000

333 3

2.1. The simplified seismic vulnerability and damage models.

Vulnerability is assessed per structural unit based on a small number of indicators deemed most significant. The quantification of the vulnerability level is done by means of a scoring system that defines for each deficiency the three levels of increasing vulnerability V1, V2 and V3. The model provides that overall vulnerability is assessed as the sum of the scores associated with the individual indicators shown in Table 1, according to the classes shown in Table 2.

Table 1. Scores given to the nine vulnerability indicators used for masonry buildings. n. vulnerability V3 V2

V1

1 2

Quality of masonry

15

8 4

4 1

Quality of masonry connections to angles and hammers. Presence of masonry bearing in false, at least on one level, on horizontal structures for at least 10% of the area in plan. High spacing between successive bearing walls in relation to the thickness of transverse masonry. Orientations: Connection to vertical load-bearing structures. Roof structures: Connection to vertical load bearing structures. Presence of decks set on staggered planes with a difference in height greater than 1/3 of the storey height. Connections between non-structural elements and the structure.

6

3

3

0

0

4

4

2

0

5

10

5

0

6

8

5

2

7

4

1

1

8

4

2

0

9

Location in the aggregate.

3

0

0

Table 2. Overall vulnerability level assessed as the sum of the scores given in the table above. vulnerability score V3 ≤ 40 V2 >20 e < 40 V1 ≤ 20

The level of overall damage to structural masonry units is assessed for each structural component based on the severity of damage and its extent using a matrix similar to the one provided in the AeDES form and is calculated as: (1 ) 5

å å = çç è æ × 1 1 j i

÷÷ ø ö

P

× R E P

=

tot

j

j

Where i is a counter referring to the structural components, j is a counter referring to the columns of the damage extension matrix, R i represents the weight assigned to each of the structural components, E j represents the extent of

damage P j , P j is a score proportional to the level of damage. The overall damage level is then normalized to the unit value:

(2)

P D P =

tot

rif

Where P rif is the P tot index evaluated for a reference damage given by the conditions of very severe damage on all structural components for an extent greater than 2/3 of the components. The normalized global damage value D has values ranging from 0, where no damage has been found, to 1, where collapse has occurred. The global damage level is calculated according to the following table.