PSI - Issue 44

Romina Sisti et al. / Procedia Structural Integrity 44 (2023) 1380–1387 Romina Sisti et al. / Structural Integrity Procedia 00 (2022) 000–000

1382

3

Each inspection is associated with the maximum value of PGA occurred before the inspection date. The PGA values for each church and for each shock of the seismic sequence are obtained by interpolation from the data provided by INGV (National Institute of Geophysics and Volcanology). In particular, 60% of the churches (1735) experienced PGA lower than 0.1 g, 23% (668 churches) experienced PGA in the range 0.1-0.2 g, 8% (242 churches) in 0.2-0.3 g, 6% (173 churches) in 0.3-0.5 g, 2% (66 churches) in 0.5-0.8 g. It is worth noting that only 8% (239 churches) experienced accelerations higher than 0.3 g. For this reason, the width of the PGA intervals used for the definition of the damage matrices and the fragility curves is not constant but increases as the PGA increases. The A-DC form collects general information regarding each single church (such as location, use…), while it does not systematically collect information on its typological and structural characteristics (such as the shape of the plan or the type of masonry), which can only be deduced from notes, drawings or photographs attached to the form. With reference to the entire database (2884 churches), Fig. 1a shows that most of the sample (62%) is made of churches with a rectangular plan, of which 87% is characterized by a single nave. The other plan shapes have percentages never higher than 3% of the database, still mainly provided by a single nave. For 30% of the database, the information about the plan is lacking. The distribution of the planimetric surface of the churches is shown in Fig. 1b. The average plan surface of the churches is 187 m 2 and a high percentage of churches have small dimensions (18% less than 50 m 2 and 27% between 50 and 100 m 2 ). Fig. 2 illustrates other characteristics of the database: type of façade, presence and type of bell tower, regularity/irregularity and typology of masonry materials. About 50% of the churches have a gabled façade, 11% a quadrangular façade, and 5% a salient façade. A real bell tower is adjacent to the church in only 18% of the cases, it is completely integrated with the church in 14%, and represents an isolated structure only in 1%, while for 33% of the churches there is only a bell gable. The irregular masonry is more diffuse than the regular one (36.3% vs. 18%), while the type of masonry is unknown in about 45% of the sample. The rubble stone is the prevalent masonry typology (29%), followed by the brick one (11.2%).

10% 15% 20% 25% 30%

Number of naves:

1 2 3 4 n.a.

3 3

88% 87%

8%

2

Not available (866; 30%) Central plan (43; 1.5%) Greek cross plan (25; 0.9%) Crux immissa (92; 3.2%) Crux commissa (76; 2.6%) Rectangular (1782; 61.8%)

9%

27%

18%

2

66%

29%

17%

0% 5%

9% 10% 6% 5%

8%

60%

32%

% of churches

>500m2 300-500 m 2

14%

79%

7%

300-500m2 300-500 m 2

150-200m2 150-200 m 2

100-150m2 100-150 m 2

200-300m2 200-300 m 2

50-100 m 2

0-50 m 2

86%

12%

2

0-50m2

50-100m2

0% 20% 40% 60% 80% 100%

plan surface

a) b) Fig. 1. Distribution of geometrical issues in the churches of the database: a) Plan shape typology and number of naves; b) Plan surface.

a. Type of façade

b. Type of bell tower

c. Masonry regularity

d. Masonry material

1%

18%

18%

23 %

31 %

29%

46%

46%

51%

14 %

10%

36%

9%

3% 11%

11%

33%

5%

5%

Gabled

Isolated Adjacent Integrated Bell gable Not present Not available

Regular Irregular

Rubble stone/pebble

Salient façade Quadrangular

Cut stone

Not available

Brick Mixed

Other

Not available

Not available

Fig. 2. Distribution of typological and structural features in the churches of the database.