*2.1. Structural Element Data*

The evaluation of the seismic behaviour of structural components in masonry buildings is based on the macro-element approach, which means on the identification of architectural portions of the building 'characterised by a substantial autonomous structural response' [27] compared to the whole building. Macro-elements are defined on the basis of archive documentation and constructive investigations, and are often recognised as typical architectural elements (e.g., for a church: façade, apse, bell-tower, triumphal arch, etc.). In fact, in the absence of good connections (both wall-to-wall and wall-to-floor/roof), sufficient stiffness of the horizontal components, and regularity (both at geometric and behavioural level), the masonry building cannot activate the ideal 'box-like' behaviour, and single brittle rigid body mechanisms can occur, mainly out-of-plane (the so called 'mode 1'). These mechanisms can provoke severe losses (also related to supported artworks) and collapses, before any in-plane ('mode 2') behaviour can be activated [28,29]. Nevertheless, a primary fundamental condition to be checked is the presence of possible indicators of masonry quality [30], as brittle masonry disaggregation (the so called 'mode 0', [31]) can occur before any other mechanisms. Evidently, a low masonry quality also severely affects the safety and integrity of the artworks that are integral to the architectural element, even with a very low seismic hazard.

With regards to the SE, the new survey forms collect values as optimized parameters derived from the church and palace damage forms [19,20]. Levels I and II differ for the type and extension of information, so that they can support quick or more extensive onsite evaluations, respectively. The case study, as named in the forms, is the AA, to which the various conditions of the connected SE are considered. Both damage and vulnerability indicators are included, as follows.

At first, the building in question is identified, and the possible availability of previously filled forms (the aforementioned forms for churches and palaces) regarding a specific earthquake can be mentioned.

At level I, the AA and its related SE are identified only with their localisation in the building. Then, each SE (e.g., wall, column, vault, or other) is described in terms of masonry type (material and dimensions, the latter could be measured or estimated) and with the identification of the main damage mechanisms, the origin (i.e., due to seismic action, pre-existing, or simply because of deterioration) and importance (i.e., either primary or secondary) of which should be specified. The possible mechanisms are listed as selected items from the form available for churches (28 mechanisms) and for palaces (22 mechanisms), and the damage level is identified on a scale of 1 to 5, according to the EMS-98. Figures 3 and 4 show the damage mechanisms included in the DataBAES forms, and the five damage levels as provided by EMS-98, respectively.

For the primary mechanisms, additional data can be provided about in-plane or out-of-plane damage details for walls (e.g., overturning activation, spalling, crushing, or collapse), as well as about the extension of potential cracking for vaults and columns. Details on cracking are also included, since these can affect the integrity of the AA in terms of extension and type (crazing, passing through, rough estimation of crack opening, etc.). At level I, damage evaluation is predominant, hence the presence of vulnerability indicators and of earthquake-proof devices is simply declared and kept as an overall recognition of potential additional issues for the building.

**Figure 3.** Example of mechanisms for masonry churches and buildings adopted in DataBAES forms, as shown in church (A-DC, 28 mechanisms) [19] and palace (B-DP, 22 mechanisms) [20] survey forms.

**Figure 4.** Damage degrees for masonry structures according to EMS-98 (reproduced with permission from G. Grünthal [24]).

At level II, the form requires the identification of the AA and its related SE with the primary or secondary mechanism having already been identified (Figure 5). In fact, at this level, each of the 28 mechanisms for churches or the 22 mechanisms for the other types of buildings are analysed in detail, both in terms of damage and the presence of specific vulnerability/devices. In the case of non-structural elements supporting artworks (e.g., *camorcanna* vaults), the mechanism should be identified as that of the macro-element, which could affect the one of the non-structural elements in question (e.g., the possible overturning of walls supporting the *camorcanna* vault). For the increasing damage evaluation, a grade from 1 to 5 is required, whereas for the vulnerability assessment the increasing overall scale of 1 to 5 is derived from the detailed evaluation of each item based on a three-grade scale, according to the effectiveness of potentially good construction details and/or earthquake-proof systems (e.g., ties, buttresses, connections and anchors, light bracing, and lintels). This scale corresponds to 'ineffective' (any check box marked), 'moderate' (grade 1), 'good' (grade 2), and 'completely effective' (grade 3). Vulnerability concerns the presence of thrusting elements (roof struts, arches, and vaults), slender piers, large openings close to corners, stiff ridge beams, heavy floors/roof, high-span thin vaults, etc., and is expressed on the scale of 1 to 5 corresponding to the grades 'very low'–'low'–'average'–'high'–'very high'.

Space for notes and schematics is available in the form where needed. The specific items required for SE are reported in the level I and level II forms included in the Supplementary Material of this paper.

**Figure 5.** Example of primary and secondary mechanisms associated with a damaged fresco located in apse of a church: (**a**) apse is subjected to 'overturning', but the main mechanism affecting fresco is 'shear'; therefore, 'in-plane mechanism of apse' and 'overturning of apse' are, respectively, primary and secondary mechanisms; (**b**) damage to the vault of the central nave affects the painting as a primary mechanism.

### *2.2. Artistic Asset Data*

Artworks in historical buildings are exposed to deterioration and damage according to their specific features and conservation conditions. Calò et al. [32] defined a methodological approach for the restoration of artistic assets. In particular, the initial phases of anamnesis and analysis of the application techniques were clarified; nevertheless, the study does not include any evaluation of intrinsic risk parameters. Application techniques, such as the half-dry mural technique, have always been considered an initial factor in degradation [33,34]. However, also in this case, the comparative analysis of risk is missing.

In this paper, the risk of damage has been parametrized on the basis of the following three factors: (i) the construction technique and any application (i.e., intrinsic) faults; (ii) the position where the artworks are located (e.g., wall support, canopy, vertical and horizontal position); (iii) the state of conservation (the passage of artefacts over time). This approach allows predictions to be made and therefore enable us to identify where the greatest damage to artworks could occur. As a result, information for the planning of maintenance and interventions is provided. Moreover, in the DataBAES archive, for a more comprehensive risk analysis, the specific issues of artworks are also combined with the possible effect of earthquakes on the supporting structural element according to two levels of investigation.

At level I, wall paintings/frescoes, stuccoes, and mosaics are recognised as immovable artworks integral to the building structure. The possibility of identifying an artistic cycle is also taken into consideration. At first, the overall maintenance state should be defined, then 12 items derived from [22,23] are selected as a representative list for damage evaluation (Figure 6 shows some examples). The surveyor should also in this case check whether the detected damage has been caused by seismic activity or is a consequence of pre-existing damage or an effect of direct deterioration. A specific judgment on a scale of 1 to 5 is required for each item on the list, followed by an overall judgment related to all the 12 items. At such a level, as for the structural evaluation, the vulnerability does not require any quantification; nevertheless, the main aspects to inspect are defined so that they can be recognised for further analysis provided by level II. These aspects are specified for the three types of AA (i.e., wall paintings/frescoes, stuccoes, and mosaics) and are related to application technique, i.e., compositional and finishing issues, and vulnerability, by taking into consideration the placement position and the interaction with possible additional interlay elements (e.g., *camorcanna*, reed wattle, etc.).

**Figure 6.** Examples of the deterioration of wall paintings and stone artworks according to current charts for classification of surface decay [22,23].

At level II, the description and the evaluation of damage is similar to that of level I, but the list of possible types of damage is increased up to 25 items. Vulnerability is distinguished by those derived by the application technique and other inherent variables. In both cases, specific parameters are taken into consideration, each of them quantified by a coefficient. For each type of AA (i.e., wall painting/fresco, stucco, and mosaic), in addition to general information, such as finishing or placement technique, the thickness, inert/binder ratio, and grain size are specified, which represent potential critical aspects. The other inherent variables are related to the presence of sulphation, solubilisation, organic material, crazing, wood or metal inclusions, and of products due to the incorrect mixing of basic components. These products can be: '*bottaccioli*' (i.e., inert agglomerate not mixed with the binder inside the mortar causing the punctual fall of original material due to the loss of adhesion); '*calcinaroli*' (i.e., binder agglomerate without bonding that, with the absorption of humidity, causes binder swelling and original material to fall); '*gessaroli*' (i.e., plaster agglomerates in powder dispersed in the mixture of chalk and water caused by bad mixing; the absorption of chalky material provokes swelling and the fall of original material in humid conditions). The presence of these variables higher than 30% must be accompanied by the parameter to which it refers. Table 1 shows the quantification of parameters for vulnerabilities related to wall paintings. It is important to underline how the judgment on the overall damage must be expressed based on the extent or quantity of the artefact that has been damaged, regardless of its artistic relevance.

A proportional calculation that balances the risks with respect to extrinsic and intrinsic factors (executive techniques, the state of conservation, and the effects of the earthquake) based on a scale of 1 to 5 was proposed. This approach results in a weighted average, which is useful for defining intervention priorities and monitoring for the best preservation of the cultural asset. Lastly, the presence of intrinsic variables caused by degradation, which may have influenced the progression of the lesions and contributed to the detachment of portions, is checked. Any further information can be inserted into the 'notes'. The item's 'thickness' for the stuccoes and the 'finishing technique' for stuccoes and frescoes can be compiled with more than one value, since these characteristics can be present to an equal extent.

At the end of the II level form, a list of damage and vulnerability levels evaluated for each AA and its related SE is provided, so that a comparison of those levels can be made for all case studies (i.e., AA) identified in the building. This evaluation is processed automatically in the DataBAES archive once the forms have been filled out on the web platform, so that a colour scale may appear immediately for quick correlations. The same procedure also applies to the level I form, although it is limited to a damage comparison.

The specific items required for AA are reported in the level I and level II forms included in the Supplementary Materials of this paper.

**Table 1.** Example of quantification of vulnerability of wall paintings/frescoes/plasters (all compositional stratigraphy) with respect to the application technique and inherent variables.


\* applicable to all inherent variables.
