**The Role of the Water Level in the Assessment of Seismic Vulnerability for the 23 November 1980 Irpinia–Basilicata Earthquake**

#### **Davide Forcellini**

Department of Civil and Environmental Engineering, University of Auckland, 20 Symonds Street, Auckland 1010, New Zealand; dfor295@aucklanduni.ac.nz

Received: 30 April 2020; Accepted: 12 June 2020; Published: 13 June 2020

**Abstract:** The seismic vulnerability of structures is closely related to changes in the degree of soil saturation that may cause significant changes in volume and shear strength, and consequently, bearing capacity. This paper aims to consider this issue during the strong earthquake that struck Southern Italy on 23 November 1980 (Ms = 6.9) and affected the Campania and Basilicata regions. Several 3D numerical finite element models were performed in order to consider the effects of soil–structure interaction (SSI) on a representative benchmark structure. In particular, the role of the water level depth is herein considered as one of the most significant parameters to control the shear deformations inside the soil, and thus the performance of the superstructure. Results show the importance of considering the water level for buildings on shallow foundations in terms of settlements, base shear forces and floor displacements.

**Keywords:** Irpinia–Basilicata earthquake; seismic assessment; soil–structure interaction; numerical simulations; OpenSees

#### **1. Background**

The historical 23 November 1980 Irpinia–Basilicata (Southern Italy) earthquake (Ms = 6.9) showed the importance of assessing seismic risk for Italian communities. In particular, earthquake vulnerability depends on the mechanisms occurring inside the superficial layers that filter the input motion from the bedrock. Many parameters may drive these mechanisms, such as soil properties, bedrock characteristics, layers depth, stratification and water level. In particular, the effects caused by water level may modify the vertical pressures on the soil layers, as observed and discussed by [1,2]. Other contributions showed the importance of controlling the water table as a soil improvement [3,4]. In addition, the correlation between shallow groundwater levels and liquefaction occurrence is proposed by [5] for the May 2006 earthquake at Yogyakarta (Indonesia). In addition, [6] showed the effects of water level on analytical indexes for liquefaction susceptibility, while [7] investigated the effects of water table level during the recent Emilia Romagna earthquake, where the oscillations were shown to be limited to less than 2 m.

In this regard, there are many approaches to measure the depth of the water table. One of the most common consists of applying piezometers that are typically inserted into the soil at different depths below the surface with measurements made manually or automatically with a continuous registration [8]. As shown in [9], other interesting issues are the density, the frequency of measurement sites, the spatially interpolating point data and the extrapolating of the water table depth procedures. In this regard, interpreting redoximorphic features [10] is another common methodology in routine soil surveys. More extended approaches that allow for the prediction of the variation of shallow water table are based on climatic records, field evidences from soil morphology and properties, outputs of physically based water balance models and combinations of the different approaches. Soil morphology

is particularly valuable for interpreting water table dynamics in the soil profile [11], and simulation models were recently proposed (e.g., [12]).

After the 23 November 1980 Irpinia–Basilicata earthquake, several contributions considered the various mechanisms of rupture [13–17] and estimated damages [18], which focused on the effects of spectral accelerations [19–21] or quantified the consequences [22–24], and proposed several models [25,26]. Even with such extended literature, information regarding the level of the water table was not registered; this paper proposes numerical simulations of 3D models with different water levels in order to investigate the role of this parameter on the seismic vulnerability of the structure, which was previously investigated [27]. In particular, the effects of water level are relevant especially in the case of shallow foundations, since they are more sensitive to the change of the vertical stresses due to changing water level. For example, [28] showed that structures with shallow foundations on soft soils are expected to experience big damages and losses due to soil–structure interaction (SSI), which can be beneficial, detrimental or uninfluential on the seismic vulnerability. In addition, [29] showed that considering SSI for unreinforced masonry (URM) buildings with shallow foundations is non-negligible and that taking into account the inelastic behaviour of the soil foundation system may lead to smaller structural displacements. Furthermore, [30] focused on the mechanisms at the base of the permanent deformation of the soil to conclude that buildings founded on shallow foundations are particularly vulnerable to seismically induced settlements.

With this background, the present paper aims firstly at covering the lack of information regarding the position of the water level during the Irpinia–Basilicata earthquake by presenting a case study to assess the most detrimental water level conditions under which the earthquake may have occurred. Secondly, this paper proposes an attempt to generalize the outcomes presented to other seismic assessments by accounting the water level position, which is an important source of uncertainty, and sometimes underestimated or even neglected. The methodology applied in this paper consists of performing advanced 3D finite element models of the entire system (soil + foundation + structure) that allow consideration of the soil nonlinear mechanisms of shear deformation. In particular, different positions of water level were considered in order to assess several saturated conditions among the homogenous 20 m layer selected in the previous work [27]. The structural configuration performed is representative of the Italian residential buildings that were mainly damaged during the Irpinia–Basilicata earthquake, and consists of a reinforced concrete (RC) structure with infilled masonry walls. In particular, the documentary sources are based on two main typologies of technical data preserved in local archives: the "Scheda A" and "Scheda B" (Figure 1), which report the damages to the buildings and were fundamental tools to detect the level of damage to the buildings, [31,32]. These were used to summarize the data from the surveys that were carried out in two phases: the first, to evaluate the conditions of the entire building (Scheda A) and the second, to verify the effects on each housing unit (Scheda B) [18]. Other important documents are the recovery plans (named "Piani di Recupero") of the historical centres, and sources used to analyse the outcomes of the earthquake at the urban scale. For an extended literature review, please refer to [27]. Results in terms of settlements, accelerations, base shear forces and floor displacements are calculated in order to assess the most detrimental positions of the water level.

**Figure 1.** Example of Scheda B [31].

#### **2. The Irpinia–Basilicata Earthquake**

The 23 November 1980 Irpinia–Basilicata earthquake (Figure 2) may be considered one of the strongest earthquakes recorded in Italy [18,24,33–37], causing profound changes in communities and extended damages to civil structures and infrastructures. In particular, [18] conducted an extended literature review showing that the knowledge of the damages focused on some of Campania's and Basilicata's most heavily damaged towns, but without a systematic study. In particular, estimations assessed that approximately 1.85 million buildings were involved in the event, with 75,000 destroyed, 275,000 seriously damaged and 480,000 slightly damaged. In addition, the environmental effects induced by the 23 November 1980 Irpinia–Basilicata earthquake were also significantly severe since primary and secondary effects (such as hydrological variations and liquefaction-induced mechanism) brought important natural modifications to the natural conditions [27], such as ground deformations, slopes, landslides, lateral displacements and settlements, which were extensively documented by several contributions [37–43].

The damaged buildings consisted mostly of reinforced concrete (RC) structures characterised by infilled masonry walls (IMWs), the object of this paper (see next section). Specific studies were carried on as recovery plans (named "Piani di Recupero") and described the procedures to recover the historical centres. These plans are useful as sources of information regarding the seismic effects at the urban scale [27,44–49].

**Figure 2.** Macroseismic field of the 23 November 1980 Irpinia–Basilicata earthquake [18] (MCS = Mercalli Cancani Sieberg scale).

#### **3. Methodology**

SSI consists of several mechanisms that define the mutual behaviour of the soil, the foundation and the building, and consequently affect the structural performance. The water level depth modifies the vertical pressures in the soil and thus the shear mechanisms that cause soil deformations and settlements at foundation levels, and, consequently, stresses in the superstructures that affect the whole behaviour of the system. The proposed 3D finite element models (Figure 3) aim to reproduce these complex nonlinear mechanisms to represent realistically the behaviour of the entire system (soil + foundation + structure). This goal is particularly challenging because of the mutual effects of two sources of nonlinearity: the shear mechanisms in the soil and the structural behaviours. The study proposed here is based on the previous contribution [27], here extended to consider the role of water level depth.

**Figure 3.** Mesh 2: soil–structure interaction (SSI) model; uniform soil layer (blue), infill (green) and foundation (yellow) [27].

The input motion performed (Figure 4), selected from the Italian Accelerometric Archive [50], consists of the registration at the Sturno (STN) station (latitude: 41.0183◦, longitude: 15.1117◦) in Avellino, Campania, which is defined on soil B (following the Eurocode 8 classification); more details are available in [27].

**Figure 4.** Selected input motion (longitudinal direction) [27].

The tridimensional (3D) models performed are based on the *u–p* formulation (*u* is the displacement of the soil skeleton and *p* is the pore pressure), defined in detail in [51] and [52]. The *Pressure Depend Multi Yield02* model [53,54], selected to represent the soil layer, consists of a multi-yield-surface plasticity framework that may reproduce the mechanism of cycle-by-cycle permanent shear strain accumulation in incoherent soil materials, as shown in [55]. The model is based on the definition of several parameters, such as the low-strain shear modulus, the friction angle, shear wave velocity and permeability, shown in Table 1. In particular, an equivalent uniform linear layer was adopted in order to calculate the soil fundamental periods [56]. Note that the paper aims to reproduce a historical event and geotechnical parameters for superficial layers are currently not available for the Irpinia–Basilicata earthquake, as specified in [27]. The data that are necessary to be implemented in a numerical model require material characterizations with in situ tests that are impossible 40 years after the earthquake occurred, since soil materials and hydraulic conditions have changed significantly. Therefore, the values in Table 1 were defined on the available information (mainly [20]) and the free-field study that was carried out in [27].



Figure 5 shows the water levels performed, corresponding to the six numerical models that were performed in this study. The dimensions of the mesh were calibrated with a calibration procedure [27] and the final ones were 118.4 × 124.4 × 20.5 m. A total of 31,860 nodes and 35,868 20-node *BrickUP* elements were applied, following the previous contributions [57–59]. As explained in [27], S2 is implemented amongst the soil materials that were considered in Table 1.

**Figure 5.** Performed water levels.

Boundary conditions are fundamental when SSI analyses are carried out, especially to represent correctly the development of pore pressures. The penalty method with a tolerance value of 10−<sup>4</sup> was chosen to ensure strong constrain conditions without computational problems associated with conditioning of the system of equations (more details in [60,61]). Base boundaries (20.5 m depth) were considered rigid and all the directions were constrained. In order to allow shear deformations, longitudinal and transversal directions were left unconstrained in correspondence with the lateral boundaries, while the vertical direction (described by the third Degree of Freedom (DOF) of the nodes) was constrained. Hydraulic conditions were defined on the fourth DOF of each node that were blocked during the gravity analyses (step 1) and then released when hydraulic conditions were applied (more details in [60,61]).

The structure consists of an RC building with infill masonry walls (RCIMW) as a benchmark, in order to represent the Italian residential buildings that were mostly damaged during the 1980 Irpinia–Basilicata earthquake, and already studied in [27]. Figure 6 shows the structural scheme consisting of 4 × 2 columns (4 columns in the transversal direction (spaced 8 m apart) and 2 columns in the longitudinal direction (spaced 10 m apart) and 3 floors (a 3.4 m-storey height, 10.2 m total height). RCMIW is a typical Italian system based on two schemes (Figure 6): RC concrete columns and beams are superposed on vertical masonry walls. It is worth noting that the structural configuration performed here is a simplified version of frame-type buildings because detailed information should have required material characterizations with in situ tests that are almost impossible after 40 years from the earthquake, since the conditions of the materials could have changed significantly. Both vertical and horizontal elements are composed by RC concrete columns and beams, respectively, and characterized by fibre section models. *Concrete02* material (Figure 7a,b [27]) is chosen to model the core and the cover portions. A total of 30 bars are used and represented by *Steel02* material (Figure 7c [27]). The masonry walls are modelled as equivalent diagonal *elastic Beam Column* elements [53,54], in both longitudinal and transversal directions. The masonry walls properties are selected based on the Italian code provisions, as shown in [27]. Table 2 shows the vibration periods of the structure with and without the infill masonry walls, related to the fixed-base condition (no SSI effects included). It is worth seeing that the masonry walls affect the structural natural period (from 0.3012 to 0.2085 s), since they increase the lateral stiffness of the whole structure (as shown in [27]).

**Figure 6.** Structural 3D model [27].

**Figure 7.** *Cont.*

(**c**)

**Figure 7.** Shear stress vs. shear strain relationship for Concrete02: core (**a**) and cover (**b**) and Steel02 (**c**) [27].

**Table 2.** Structural periods; reinforced concrete (RC), infill masonry walls (IMWs).


The foundation is modelled as a 0.50 m-deep rectangular concrete raft foundation (28.4 × 34.4 m) in order to represent recurring shallow foundation typologies for residential buildings. The foundation considered is assumed to be rigid, by tying all the columns base nodes together with those of the soil domain surface, using *equalDOF* [53,54]. The foundation is modelled with an equivalent concrete material, by applying the *Pressure Independent Multi-Yield* model [53,54] (Table 3). The first 0.5 m-deep soil layer around the foundation is modelled with a backfill defined by the *Pressure Depend Multi Yield* model [53,54] and Table 4 shows the adopted parameters, such as the low-strain shear modulus, the friction angle and the permeability. The number of yield surfaces is equal to 20.


#### **Table 4.** Infill soil characteristics.


#### **4. Results**

This section shows the results of the models performed, focusing on the performance of the soil, the foundation and the structure. The vertical stresses in the soil depend on the weight of the water

for those models where the material is submerged and saturated conditions occur. It is worth noting that the effects connected with the water level can potentially be related with liquefaction occurrence, which is not considered in this paper because no historical relevancies of such phenomenon were found in the literature.

#### *4.1. Soil Results*

Significant values of the main soil parameters are herein compared in correspondence with different positions and different water depths, with particular attention to the role of water level. Figures 8–12 show the relationship between the effective confinement pressures and the shear stress at various depths in correspondence with model-10 m that was chosen herein to underline the two different conditions of saturated and dry soil. It is worth noticing the role of the water in generating several levels of confinement and the increase of the shear stress with the soil depth. In order to ensure that liquefaction did not occurred, the pore pressure ratio (ru), defined as the ratio between the total pore pressure and the total overburden pressure [60,61], was calculated and it was verified that the maximum value (0.57) was significantly smaller than 1, the value that is considered for liquefaction occurrence. Figures 7 and 8 show the conditions of dry soil and that the effective confinement pressures depend on the vertical stresses. The role of the water in increasing the effective confinement is shown in Figures 10–12, where it is possible to see the maximum level reached for the several depths: approximately 170, 220 and 250 kPa corresponding to depths of 11.50, 15.50 and 19.50 m, respectively.

**Figure 8.** Model-10 m: effective confinement vs. shear stress at 3.50 m depth.

**Figure 9.** Model-10 m: effective confinement vs. shear stress at 7.50 m depth.

**Figure 10.** Model-10 m: effective confinement vs. shear stress at 11.50 m depth.

**Figure 11.** Model-10 m: effective confinement vs. shear stress at 15.50 m depth.

**Figure 12.** Model-10 m: Effective confinement vs. shear stress at 19.50 m depth.

Figures 13 and 14 show the acceleration time histories in correspondence with the two extreme conditions (fully saturated and dry) at the surface and at −16.5 m depth. It is worth seeing that in the lower layers, dry conditions (water level at −20 m, Figure 14) are shown to be more detrimental while at the surface fully saturated conditions show large acceleration values (Figure 13).

**Figure 13.** Acceleration time histories at the surface for model-0 m and model-20 m.

**Figure 14.** Acceleration time histories at −16.5 m depth model-0 m and model-20 m.

#### *4.2. Foundation Results*

Foundation settlements (mainly differential) are one of the most significant causes of damage, depending on several parameters, like material quality, geometry of the structure, amount of openings, type of foundation or the actual state of preservation. Figure 15 shows the time history of absolute settlements (in the centre of the foundation) for the various models, demonstrating the role of the water level depth in the development of settlements. It is worth noting that the settlements start in correspondence with the peak of the input motion (compare with Figure 4); they increase and then they remain stable around the residual values (Table 5). These values were verified to be lower than the condition defined as serviceability level SLS1 (1/25) in the New Zealand code (NZS 1170.0:2002). It is worth considering that the calculated values are not comparable with liquefaction occurrence (compare with the values assessed in [60,61]).

**Figure 15.** Foundation settlements.


**Table 5.** Foundation settlements.

Figure 16 shows the normalized foundation tilt time histories, defined as the ratio between the differential foundation settlements and the width (along the longitudinal direction: 15 m). It is worth seeing that the tilts are related with the water level depths (maximum values: 1.20% and 0.60% for water levels at the surface and at −2 m depth, respectively). In addition, the main tilts are shown between 5–12 s, where the water level at the surface is shown to be at the most detrimental condition. At the end of the motion, the values of the tilts (particularly for 0 and −2 m) increase due to shear resistance and associated accumulation of permanent deformations in the soil [52]. It is important to notice that these nonlinear mechanisms were reproduced thanks to the 3D numerical models performed, which implemented advanced material models and procedures developed inside the OpenSees platform [53,54]. The permanent deformations in the soil and the foundation tilts are both responsible for transferring significant stress to the superstructure and thus contribute to the SSI effects (shown in [27,60,61]) and described in the next section.

**Figure 16.** Foundation tilts.

#### *4.3. Structural Results*

This section investigates the role of the water level on the structural performance in terms of shear forces at the base of the column and floor displacements at the top of the structure. Figures 17 and 18 show the relationship between the longitudinal displacements and base shear forces in the fully saturated case (0 m) and the dry case (20 m). It is worth noticing the different values of the displacements, due to the levels of deformations that occur in the soil, in correspondence with the two different water levels and that depend on the local soil effects, as discussed in [27]. The fully saturated case shows values of displacement that are more than two times the ones that occur for the dry case. The values of the shear forces are different as well, with maximum values of 390 kN for the case of 0 m (Figure 17 and [27]) and 307 kN for the case of 20 m (Figure 18). In particular, the maximum tensile stresses are approximately 65 kPa (for Model-0 m) and 53 kPa (for model-20 m), corresponding to two different levels of damage and thus the potential collapse mechanisms of the masonry wall [27].

**Figure 17.** Model-0 m: base shear.

**Figure 18.** Model-20 m: base shear.

To consider the effects of the structural performance, Figure 19 shows the time histories of the floor displacements (for all the performed models) in correspondence with the top of the building. Table 6 shows the maximum displacements, demonstrating that in the case of fully saturated conditions (0 m), maximum displacements are more than four times the values reached for the dry conditions (20 m). Comparing the results in correspondence with the different levels, it is possible to see that the peak values (around 6 and 12 s) of the displacements are reached for the highest positions of the water level (at the surface and −2 m). Regarding the values of the displacements at the end of the transient, intermediate water level positions (−6, −10 and −15 m) are shown to be the most detrimental conditions. These results may depend on the delay in developing permanent deformations due to the highly nonlinear mechanisms, both in the soil and in the structure. The results also show the importance of performing the 3D advanced models to represent realistically the interaction between soil deformability and structural flexibility.

**Figure 19.** Top displacement time histories.



#### **5. Discussion**

The results demonstrated the role of the water level in modifying the response of the entire system (ground–foundation–structure), with particular attention to the consequences on the structure. In this regard, as shown in [62], the presence of the masonry infill walls increases the lateral stiffness and introduces different mechanisms that significantly modify the seismic behaviour, and thus the structural vulnerability of the structure. In particular, the role of the shallow foundation is important in affecting the global stability of the system, being particularly sensitive to the nonlinear soil behaviour (such as gapping, sliding and uplift) that may lead to an unconservative prediction of the superstructure response, as shown in [29]. The role of the water level was demonstrated to be relevant, especially in correspondence with the base floors, which are characterized by large displacements that contribute to the failure of the diagonal elements (representing the masonry infill walls). In this regard, the global behaviour of the system is affected by the complex of mutual nonlinear effects of the soil and of the structure that is generally recognized as SSI, and that depends on the dynamic characteristics of the structure and the foundation soil. By this way, performing 3D advanced nonlinear numerical models was fundamental in order to assess realistic estimations of the structural vulnerability.

#### **6. Conclusions**

The paper investigates the role of the water level on a typical Italian building during the 23 November 1980 Irpinia–Basilicata earthquake by performing several 3D numerical models of the entire system (soil–foundation–structure). The finite element models were built with the advanced computational framework OpenSeesPL in order to assess the several mechanisms known globally as soil–structure interaction (SSI). The results show that the shear mechanisms and the consequent permanent deformations inside the soil are driven by the presence of the water. Therefore, knowing the position of the water level (and eventually how it changes during the seasons) is fundamental in order to assess the seismic vulnerability of structural configurations. In the case of masonry buildings, the water level may affect significantly the whole stability of the buildings, both in terms of settlements (absolute or tilts) and the failure mechanisms in correspondence with the structural wall. Although the findings are limited to the specified conditions performed, they may potentially be useful to propose formulations within code provisions.

**Funding:** This research received no external funding.

**Conflicts of Interest:** The author declares no conflict of interest.

#### **References**


© 2020 by the author. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).

### *Article* **Soil–Structure Interaction Assessment of the 23 November 1980 Irpinia-Basilicata Earthquake**

**Daniele Mina <sup>1</sup> and Davide Forcellini 2,\***


Received: 17 March 2020; Accepted: 20 April 2020; Published: 22 April 2020

**Abstract:** This paper aimed to present a systematic study of the effects caused by the strong earthquake that struck southern Italy on 23 November 1980 (Ms = 6.9) and affected the Campania and Basilicata regions. Two aspects are discussed here: The broadening of the knowledge of the response site effects by considering several soil free-field conditions and the assessment of the role of the soil–structure interaction (SSI) on a representative benchmark structure. This research study, based on the state-of-the-art knowledge, may be applied to assess future seismic events and to propose new original code provisions. The numerical simulations were herein performed with the advanced platform OpenSees, which can consider non-linear models for both the structure and the soil. The results show the importance of considering the SSI in the seismic assessment of soil amplifications and its consequences on the structural performance.

**Keywords:** Irpinia-Basilicata earthquake; seismic assessment; soil structure interaction; numerical simulations; OpenSees

#### **1. Background**

The 23 November 1980 Irpinia–Basilicata (Southern Italy) earthquake (Ms = 6.9) caused deep changes in the urban socio-economic layout, and primary and secondary effects that brought about changes to the natural environment, such as landslides (e.g., Senerchia, Buoninventre, Caposele, Calitri, San Giorgio La Molara, and Grassano) [1–4]. It consisted of several rupture episodes, which occurred at 0.18 and 40 s from the foreshock, and it was assigned a surface-wave magnitude of Ms = 6.9 [5,6]. A wide area (about 3500 km2) recorded serious damage, many casualties, and 15 localities were almost destroyed, including Sant'Angelo dei Lombardi, Laviano, Lione, Santomenna, Senerchia, Pescopagano, and Balvano. It was estimated that of a total of approximately 1.85 million buildings involved in the event, 75,000 were destroyed, 275,000 seriously damaged, and 480,000 slightly damaged [6].

With respect to this event, the documentary sources are based on two main typologies of technical data preserved in local archives: The "Scheda A" and "Scheda B", which report the damages to the buildings, consisting mostly of reinforced concrete (RC) structures characterized by infill masonry walls (IMWs), which are representative of the Italian residential buildings. Eight damage levels were defined by considering the action to be undertaken, such as repairing works, evacuation, or demolition [6]. Other important documents are the recovery plans (named "Piani di Recupero") of the historical centers, the other sources used to analyze the outcomes of the earthquake at the urban scale. An important study regarding the effects of spectral accelerations was proposed by [7], who analyzed the effects of the soil on the accelerations in several locations, with particular attention to the Naples area. In addition, [8] simulated the recorded strong-motion data by computing spectral accelerations and peak amplitude residual distributions in order to investigate the influence of site effects and

compute synthetic ground motions around the fault. They simulated the expected ground motions varying the hypocenters, the rupture velocities, and the slip distributions and compared the median ground motions and related standard deviations from all scenario events with empirical ground-motion prediction equations (GMPEs). Recent earthquakes, such as the Athens (Greece, 1999) [9], the Kocaeli (Turkey, 1999) [10], the Haiti (2010) [11], and the Gorkha (Nepal, 2015) [12–14] earthquakes, showed the importance of taking into account soil amplifications. In the literature, several approaches have been applied to perform ground motion analyses including site effects: hybrid analyses that consist of a combination of probabilistic and deterministic methods (e.g., [15,16]), convolution approaches that provide modifications of the rocking hazard (e.g., [17,18]), and 1D seismic site response analyses (e.g., [19,20]).

Even if the 1980 Irpinia–Basilicata (southern Italy) earthquake is well documented with several contributions (e.g., [21–24]) and models proposed [25,26], the assessment of the role of the soil on the structural damage is still a relatively unexplored issue and this paper aimed to fill this gap. In particular, the principal aim was to propose numerical simulations of different soil conditions and assess the effects of the soil–structure interaction (SSI), which can significantly affect the seismic vulnerability of structures [27–29]. In this regard, when the superficial deposits overlie the bedrock, amplifications of the surface seismic accelerations may not be conservatively predicted by the codes. The so-called site effects consist of a combination of soil and topographical effects, which can modify (amplify and attenuate) the characteristics (amplitude, frequency content, and duration) of the incoming wave field and are primarily based on the geotechnical properties of the subsurface materials [30]. In particular, the response of the superficial layers is strongly influenced by the uncertainty associated to the definition of the soil properties and model parameters that are fundamental to assess the well-known mechanism of seismic amplifications of ground motion [31]. Therefore, accounting for the amplification effects of superficial layers has become critically important in seismic design [32] and widely adopted in many codes' prescriptions, such as Eurocode 8 [33], ASCE (American Association of Civil Engineering) standards 7-05 [34], and 4-98 [35]. These codes provide soil parameters, generally determined through geological investigations [36–40], that can largely vary even within the same area [41,42]. The methodology followed in this paper consists of a first step, where free-field (FF) analyses were computed on several layers of soil, and secondly, an SSI (Soil-Structure Interaction) analysis was performed on a selected structural configuration that is representative of the buildings that were damaged during the Irpinia-Basilicata earthquake.

#### **2. Case Study**

SSI analyses require the definition of geomechanical parameters that are fundamental to describe the dynamic soil behavior, such as the modulus reduction and damping curves (see [43,44]). According to the current state of knowledge on the Irpinia-Basilicata earthquake, strength parameters for superficial layers are not available. Therefore, it was necessary to select representative values based on available information, such as [8], for a preliminary study. These values are herein determined with free-field analyses since the actual values at each building site will slightly differ when the building characteristics are considered. In particular, the present paper aimed to model a low-rise building based on a relatively shallow foundation assuming that the ground motion amplitude, which decreases at the foundation level with respect to the free field, may be negligible [42].

The study here proposed was divided into two steps. First of all, several FF models with different soil conditions were considered (Figure 1), in order to study the effects of soil deformability on the amplification of the motion. In particular, four incoherent soils were performed on the basis of the contributions that were found in the literature. Then, a complete 3D numerical model with the soil-foundation-structure system was performed (Figure 2). The FF soil models consist of a one-layer 20-m-deep homogenous incoherent material with a 3D mesh (Figure 1). The penalty method was adopted for the boundary conditions (tolerance of 10<sup>−</sup>4), chosen as a compromise for the soil domain definition, which was modelled large enough to ensure strong constraint conditions but not too large in order to avoid problems associated with the equations system conditions. Base boundaries (depth of 20 m) were considered as rigid. Base and lateral boundaries vertical direction (described by the third degree of freedom (DOF)) were constrained, while longitudinal and transversal directions were left unconstrained on the lateral boundaries, in order to allow shear deformations of the soil. The definition of the mesh elements dimension follows the approach already adopted [45–48] and, in order to verify proper simulation of FF conditions, accelerations at the top of the mesh were compared with the FF ones, which were found to be identical, confirming the effective performance of the mesh. The benchmark structure was calibrated in order to be representative of the buildings that were present in Irpinia in 1980. In this regard, a 3-storey concrete building with masonry walls was considered.

**Figure 1.** Mesh 1: free-field analysis.

**Figure 2.** Mesh 2: SSI model; uniform soil layer (blue), infill (green), and foundation (yellow).

Dynamic analyses were performed with OpenSeesPL. The selected input motion was chosen from the Italian Accelerometric Archive [49] and it represents the acceleration registered in Sturno (STN) station (lat: 41.0183◦, long: 15.1117◦) in Avellino, Campania (Figure 3), and located less than 5 km from the fault and 33 km from the epicenter (41.76◦N, 15.31◦E). For more details, see [8]. The input was defined on soil B, as classified by Eurocode 8, and applied at the base of the model along the longitudinal direction.

**Figure 3.** Selected input motion: acceleration (**a**) and spectrum (**b**).

#### *2.1. Step 1: FF Analyses*

The soil models were built up on a two-phase material following the *u-p* formulation [50], where *u* is the displacement of the soil skeleton and *p* is the pore pressure. The soil material was based on the following assumptions: (1) Small deformations and rotations, as well as solid and fluid densities remain constant in both time and space; (2) porosity is locally homogeneous and constant with time; (3) soil grains are incompressible; and (4) solid and fluid phases are accelerated equally [51]. The 20-m-deep soil layer was defined by the *PressureDependMultiYield02* model [52,53], based on the multi-yield-surface plasticity framework developed by [54], in order to reproduce the mechanism of cycle-by-cycle permanent shear strain accumulation in clean sands (Figure 4). Table 1 shows the adopted parameters, such as the low-strain shear modulus and friction angle, as well as the shear wave velocities and permeability. Soil fundamental periods were estimated considering an equivalent uniform linear layer, following [55]. The number of yield surfaces was equal to 20 for all soil models. Figure 5 shows the backbone curves for all the selected soil models.

**Figure 4.** Multi-yield surfaces in principal stress space and deviatoric plane [53].


**Table 1.** Soil characteristics.

The 3D soil models consist of a 100 m × 100 m × 20 m mesh, built up with 8000 20-node *BrickUP* elements and 9163 nodes to simulate the dynamic response of solid-fluid fully coupled material [52,53]. For each *BrickUP* element, 20 nodes describe the solid translational degrees of freedom, while the eight nodes on the corners represent the fluid pressure 4 degrees of freedom. For each node, Degree of Freedom (DOF)s 1, 2, and 3 represent solid displacement (*u*) and DOF 4 describes fluid pressure (*p*), which were recorded using OpenSees Node Recorder [52,53] at the corresponding integration points. The element dimension increases from the structure (center of the model) to the lateral boundaries, which were modelled to behave in pure shear and located far away from the center of the mesh.

#### *2.2. Step 2: SSI Analyses*

The study considered an RC structure with infill masonry walls as a benchmark, in order to represent the Italian residential buildings that were mostly damaged during the 1980 Irpinia–Basilicata earthquake. The benchmark structure was built with a 4 × 2 column scheme (4 columns in the transversal direction (8 m spaced) and 2 in the longitudinal direction (10 m spaced)) and modelled to have periods in the range of those of residential buildings, considering 3 floors (a 3.4 m storey height, with a total structure height of 10.2 m). The structure was modelled as a superposition of two schemes (Figure 6). Both vertical and horizontal elements were composed by RC concrete columns and beams, respectively, and characterized by fiber section models. *Concrete02* material [56,57] was chosen to model the core and the cover portions (Figure 7a,b, respectively) of the section (0.40 m × 0.40 m) and with the parameters defined in Table 2. The ratio between the unloading slope (related to the maximum strength) and the initial slope was taken as equal to 0.1. A total of 30 bars were used and represented by *Steel02* material [58], with the properties shown in Table 3 and the ratio between the post-yield tangent and initial elastic tangent equal to 0.01 (Figure 8). The parameters that control the transition from elastic to plastic branches were assumed R0 = 15, CR1 = 0.925 and CR2 = 0.15, as suggested by [53]. The masonry walls were modelled as equivalent diagonal *elasticBeamColumn* elements [52,53], in both the longitudinal and transversal directions. The masonry walls' properties were selected based on the Italian code provisions, with low-to-medium mechanical characteristics (Table C8A.2.1 [59]), as shown in Table 4. Table 5 shows the vibration periods of the structure with and without the infill masonry walls. It is worth noting that the masonry walls affect the structural natural period (from 0.3012 s to 0.2085 s), since they increase the lateral stiffness of the whole structure (as shown in [60]). In particular, the infill masonry walls introduce different mechanisms that may significantly modify the seismic behavior of the structure. The foundation was modelled as a 0.50-m-deep rectangular concrete raft foundation (28.4 m × 34.4 m) in order to represent the recurring shallow foundation typologies for residential buildings. These types of foundation can be particularly vulnerable due to their bearing capacity, which depends only on the contact pressure and not on the frictional mechanisms (as in the case of deep foundations). The considered foundation was assumed to be rigid, by tying all the columns base nodes together with those of the soil domain surface, using *equalDOF* [52,53]. Horizontal rigid beam-column links were set normal to the column longitudinal axis to simulate the interface between the column and the foundation. The foundation was designed by calculating the eccentricity (the ratio between the overturning bending moment at the foundation level and the vertical forces) in the most detrimental condition of the minimum vertical loads (gravity and seismic loads) and maximum bending moments. The foundation was modelled with an equivalent concrete material, by applying the *Pressure Independent Multi-Yield* model [52,53] (Table 6). This model consists of a non-linear hysteretic material with a Von Mises multi-surface kinematic plasticity model, which can simulate a monotonic or cyclic response of materials whose shear behavior is insensitive to the confinement change. The nonlinear shear stress-strain backbone curve is represented by the hyperbolic relation, defined by the two material constants (low-strain shear modulus and ultimate shear strength) [52,53].


**Table 2.** Concrete02 (core and cover).

**Figure 7.** Shear stress vs. shear strain relationship for Concrete02: core (**a**) and cover (**b**).

**Table 3.** Steel02 (bars).

**Figure 8.** Shear stress vs. shear strain relationship for Steel02 (bars).




The 3D soil models consist of a 118.4 m × 124.4 m (20.5 m thick) mesh, built up with 31,860 nodes and 35,868 20-node *BrickUP* elements to simulate the dynamic response of solid-fluid fully coupled material [52,53] and with the same assumptions considered for the free-field models (Section 2.1). As explained in Section 3.1, S2 was implemented amongst the soil materials that were considered in step 1. The first 0.5-m-deep soil layer around the foundation was modelled with a backfill defined by the *PressureDependMultiYield* [52,53] model, based on the multi-yield-surface plasticity framework developed by [54]. Table 7 shows the adopted parameters, such as the low-strain shear modulus, the friction angle, and the permeability. The number of yield surfaces was equal to 20. Figure 9 shows the backbone curves.


**Table 7.** Infill soil characteristics.

**Figure 9.** Backbone curve (infill soil).

#### **3. Results**

In this section, the results are discussed on the basis of the assumptions made so far. In particular, it is important to state that the findings are limited to the conditions considered herein, especially to those regarding the selected soils.

#### *3.1. FF Analyses*

The selected soil profiles were considered under the assumption that the superficial layers are characterized by sand deposits with shear wave velocities in the range of 150–250 m/s. In this regard, the four materials were selected to be representative of real soil conditions from low to medium-low stiffness. Saturated and dry conditions were chosen in order to perform dynamic analyses. The position of the water table is fundamental in order to assess the performance of the system (soil + structure). However, it is extremely difficult to know this parameter in real situations. In this study, the water table depth was set at a depth of 2 m from the ground surface for the saturated condition and for all soil models. For each soil condition, transfer functions (TFs) were calculated as the ratio between the acceleration at the ground surface (depth of 0 m) and the one at the base of the soil domain (depth of 20 m), considering the selected input motion (Figure 3) along the longitudinal axis.

Figure 10 compares the behavior of S1, S2, S3, and S4 for both saturated and dry conditions for the range of periods between 0 and 1 s. It is worth considering that the role of soil deformability in the mechanism of amplification inside the range of periods of the selected structure is paramount (Table 5). In particular, S2 with the saturated condition is shown to be the most detrimental soil above which the structure can be founded (maximum amplification equal to 1.66), since the TF peak occurs in conjunction with the fundamental period of the structure (Table 5), and thus S2 is applied in the SSI model (see Section 3.2). Moreover, dry conditions are noticeable for those periods that are far from the structural ones. In general, it is possible to state that S2, S3, and S4 with the saturated condition are the most detrimental cases. On the other hand, S1 seems to behave differently from the other cases, since dry conditions are more detrimental for the structural configurations that were herein considered.

**Figure 10.** Transfer functions: S1, S2, S3, and S4 with dry and saturated conditions.

*3.2. SSI Analyses*

With the recent development of the performance-based earthquake engineering (PBEE) methodology [61–63], there has been an increasing attention in the new engineering demand parameter (EDP) to assess the structural performance of buildings, such as the floor accelerations. In particular, many codes [64–67] are implementing new provisions based on floor performance. In this regard, the

paper aimed to move in the direction of this new approach by calculating not only the peak values of the aforementioned EDP but also the top floor accelerations. This section presents the structural performance at the foundation level and along the height of the building, considering the soil S2 under saturated conditions, which was found to be the most detrimental (Section 3.1).

Figure 11 represents the rotation versus bending moment related to an RC column at the base of the structure. It is possible to see that the diagram presents the typical hysteretic mechanism registered during a seismic event. In particular, the values of the rotations are not significant, meaning that the rocking component of the foundation does not relevantly affect the performance of the structure, which is tied to the ground. The settlement of the foundation is not substantial as well (maximum 1.8 mm) and this is the reason for the low level of overturning moments and interstorey drifts (Figure 12), calculated as the ratio between the relative longitudinal displacement and the height of the floor from the foundation level.

**Figure 11.** Rotation vs. bending moment.

**Figure 12.** Drift floor time histories.

The floor spectra (5% damping), which were considered in order to assess the amplifications of the longitudinal accelerations, and thus the seismic performance of the structure, are represented in Figure 13. It is worth noticing that the peaks correspond to the fundamental period of the structure (as expected), demonstrating that the numerical model performed properly. Moreover, the accelerations increase with the height of the structure (0.426, 0.628, and 0.776 g, respectively, for floor 1, floor 2, and floor 3), with amplifications for floor 2 and floor 3 of 23.5% and 82.1% greater than those resulted for floor 1. Additionally, the significant peak related to the period of 0.6 s is noticeable, where all the structures show the same level of amplification (nearly 0.9 g). This peak corresponds to a period that is close to the fundamental period of the S2 soil, and thus may be a consequence of the mutual behavior of the soil and the structure [68].

**Figure 13.** Spectra at various floors (damping ratio = 5%).

Figure 14 shows the maximum longitudinal displacements along the height of the structure. It is noticeable that the foundation maximum displacement is 1.725 cm, which means that a considerable translation occurred. In addition, since the structure is a low-rise building, the structural stiffness drives the increase in displacements along the height of the buildings and in relation to the various floors. The maximum displacement at the top of the structure is 1.885 cm, which is significant for a three-storey building in terms of structural performance.

**Figure 14.** Maximum longitudinal displacements.

Figure 15 represents the shear forces versus longitudinal displacements for the masonry walls. These outputs are fundamental in order to define the damage conditions of the wall and to determine the potential collapse mechanism. It is worth noticing that the results are somewhat significant,

demonstrating that the masonry walls are the weakest elements in the structure, as expected by the historical evidence during the 23 November 1980 Irpinia–Basilicata (southern Italy) earthquake. In particular, the maximum base shear was 390 kN and the corresponding maximum tensile stresses were approximately 65 kPa, which is close to the ultimate tensile stress. This aspect suggests that the potential damage is primarily due to the shear failure of the masonry walls.

**Figure 15.** Shear forces vs. longitudinal displacements at various floors.

Overall, the results demonstrate that the numerical model is in good agreement with the assumptions made so far, and thus the ground-foundation-structure system was simulated properly. The paper assessed the role of soil deformability in the amplification of accelerations, and thus its consequences on the structure. In particular, the outputs were chosen in accordance with the new approach proposed by the recent code provisions and the top floor accelerations and other significant EDP were calculated for the performed structure. In this regard, the values of the shear forces that occurred in the masonry elements show that shear failure may potentially occur in these elements, as expected and as proved by the damage that occurred during the 23 November 1980 Irpinia–Basilicata (southern Italy) earthquake.

#### **4. Conclusions**

The paper investigated the effects of soil deformability on a typical structural configuration by analyzing a 3-D soil–structure model built up with OpenSeesPL. The results are the consequence of several mechanisms known globally as the soil–structure interaction (SSI). The principal novelty of the paper consisted of proposing a model that performs detailed 3-D simulations of both the soil and the structure and assessing the structural performance in terms of displacements, drifts, and accelerations at various floors. Overall, the paper demonstrated that the soil may cause several spectral amplifications under free-field conditions (maximum amplifications: 1.66) and that a rigid low-rise building is sensitive to SSI effects, which need to be considered. Although the findings were limited to the specified conditions, they may potentially be useful to propose formulations that include SSI effects within code provisions. In this regard, future parametric numerical simulations on the response of other structural typologies and soil characteristics (e.g., water-level depth) will be performed.

**Author Contributions:** Please consider this paragraph that specifies the individual contributions of the authors: Conceptualization, D.F.; methodology, D.F.; software, D.M.; validation, D.M.; formal analysis, D.M. and D.F.; investigation, D.M. and D.F.; resources, D.M. and D.F.; data curation, D.M. and D.F.; writing—original draft preparation, D.M. and D.F.; writing—review and editing, D.M. and D.F.; visualization, D.M. and D.F.; supervision, D.F.; project administration, D.M. and D.F.; funding acquisition, D.M. and D.F. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research received no external funding.

**Conflicts of Interest:** The authors declare no conflict of interest.

#### **References**


© 2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).

### *Article* **Near-Real-Time Loss Estimates for Future Italian Earthquakes Based on the M6.9 Irpinia Example**

#### **Max Wyss \* and Philippe Rosset**

International Centre for Earth Simulation Foundation, 1223 Cologny, Switzerland; rossetp@orange.fr **\*** Correspondence: max@maxwyss.ch

Received: 17 March 2020; Accepted: 30 April 2020; Published: 3 May 2020

**Abstract:** The number of fatalities and injured was calculated, using the computer code QLARM and its data set and assuming information about the Irpinia 1980 earthquake became available in near-real-time. The casualties calculated for a point source, an approximate line source and a well-defined line source would have become available about 30 min, 60 min and years after the main shock, respectively. The first estimate would have been satisfactory, indicating the seriousness of the disaster. The subsequent loss estimate after 60 min would have defined the human losses accurately, and the ultimate estimate was most accurate. In 2009, QLARM issued a correct estimate of the number of fatalities within 22 min of the M6.3 L'Aquila main shock. These two results show that the number of casualties and injuries in large and major earthquakes in Italy can be estimated correctly within less than an hour by using QLARM.

**Keywords:** earthquake risk; earthquake fatalities; Italian earthquakes; Irpinia earthquake

#### **1. Introduction**

At the time of the M6.9 Irpinia earthquake of 1980, near-real-time loss estimates for earthquakes did not exist. Today however, two teams distribute these estimates for major earthquakes worldwide. The PAGER (USGS) and the QLARM (Quake Loss Assessment for Response and Mitigation) teams distribute loss alerts within 25 min and 29 min of potential earthquake disasters, respectively [1].

The question we ask in this article is how reliable are theoretical fast loss assessments in cases of major and large earthquakes in Italy? The M6.9 Irpinia earthquake is used as an example. Calculations are presented of what the estimates of fatalities and injured would have been immediately after the Irpinia earthquake. The results are an indication of the quality of loss estimates by QLARM within less than an hour of the next large earthquake neighboring the Irpinia or L'Aquila areas and, by implication, in all of Italy.

The routine by which QLARM alerts are issued in near-real-time is described by Wyss [1]. The details of the program and data sets in QLARM are given by Trendafiloski et al. [2]. Different aspects and uses of QLARM have been discussed in several articles [3–6]. Here, we do not repeat these explanations; rather, we focus on the Irpinia earthquake and the quality of near-real-time earthquake loss assessments in Italy.

Our aim in loss calculations is to estimate the total sum of fatalities that are likely as a measure of the extent of earthquake disasters. The unknown parameters within minutes after an earthquake are numerous, as all initial earthquake parameters are afflicted by significant uncertainties [7]. The direction of rupture and consequential focusing of radiated energy becomes known only later, if ever. The local wave attenuation was not known, so we used an average. Soil conditions that might amplify accelerations are not known for any specific location. Building resistance to shaking was only known approximately in an average sense, so we used an approximate model for the building types. Finally, the occupancy rate was also largely unknown, so we used 99% occupancy at night and 26% during the day.

All these unknowns mean that we cannot attempt to calculate what happens to a specific building. Instead, we rely on an average. We only have confidence in the overall sum of casualties, not even in those within one settlement, and much less those within a building. It is this overall average estimate of fatalities that we distribute minutes after earthquakes, and it is this value that would have been calculated by QLARM after the Irpinia earthquake that we are testing here.

#### **2. Building Stock Used**

An aspect of QLARM application to Italy that has not previously been explained is the distribution of buildings into vulnerability classes and their occupants. As QLARM is a tool operated pro-bono for worldwide application, we did not have the information or the resources necessary to construct detailed information on the specific buildings in each settlement. This information can be developed by special projects [8,9], but, on a worldwide basis, it was available to us only for Greece. The Greek 2001 population and building census includes information about the construction material, age and number of floors for each building (Hellenic Statistical Authority). This information allowed the classification of all building types in each settlement according to the European Macroseismic Scale 1998 (EMS98) [9] for Greece only. For other regions, like southern Europe, we used averages with three size categories. The population limits for building models we used for Italy were pop1 < 2000 ≤ pop2 < 20,000 ≤ pop3 (Table 1).


**Table 1.** Percentage of building types and percentage of the population in buildings in the three class sizes of settlements used by QLARM for Italy.

The building distribution used for Italy and people in them are listed in Table 1 and shown in Figure 1. We are not advocating these approximations to the built environment as the best option for a specific local environment, we simply needed models for all countries of the word that would yield correct results. For several countries, we verified the appropriateness of the models for building stock by determining if the theoretical estimates of the total numbers of fatalities agreed with the reported numbers in large earthquakes [5,6,10].

**Figure 1.** Percentage of building types (**a**) and percentage of the population in them (**b**) in the three class sizes of settlements used by QLARM for Italy.

#### **3. The M6.3 L'Aquila Earthquake**

In the case of the L'Aquila earthquake, the QLARM alert was correct (Table 2). This type of estimate can serve as a guide for first responders at a time when no information is available from the devastated area.


**Table 2.** Copy of the estimate of fatalities and injuries distributed by email 22 min after the M6.3 earthquake of L'Aquila in 2009 to interested parties.

#### **4. Loss Estimates for the M6.9 Irpinia Earthquake**

The loss estimates for the Irpinia event presented here were calculated as if the earthquake's parameters became available in near-real-time by SMS and no other information existed, as in the aforementioned L'Aquila earthquake. The hypocenters and magnitudes of significant earthquakes worldwide are received by users, such as QLARM, from the GFZ (GeoForschungsZentrum) and the USGS (United States Geological Survey) within 7 and 18 min, respectively. After receiving this message, shaking intensities, damage to buildings and the impact on occupants are immediately calculated. At first, only the hypocenter is known, not the extent and direction of the rupture. Also, initial hypocenter and magnitude values tend to be inaccurate. In the case of the Irpinia earthquake, it is not known by what errors the first parameter estimates were afflicted, so those parameters currently listed by the USGS (M6.9, 1980-11-23 18:34:53 (UTC) 40.914◦ N 15.366◦ E) must be used.

The map showing settlements with color-coded damage due to an M6.9 earthquake at the Irpinia epicenter modeled as a point source is shown in Figure 2. The mean damage is given on a scale from 0 to 5. The calculated pattern is circular because the direction of rupture would not have been known. This map and the casualties (both fatalities and injured) given in the first row of Table 3 would have been distributed by the QLARM team about 30 min after the rupture.

**Table 3.** Casualties calculated for a hypothetical repeat of the M6.9 Irpinia earthquake. The results are presented for three source models that would have become available with increasing accuracy as a function of time and would have been distributed with the delays given in the first column. The calculated casualties are good estimates of the reported ones and become better with the assumed increase of information.


**Figure 2.** Map of estimated mean damage in the 1980 Irpinia epicenter area, calculated for a point source with M6.9 located at 40.914◦ N 15.366◦ E and occurring at 19:35 local time. Each dot is a settlement with size proportional to population.

The location of an aftershock can provide hints about the direction and length of the rupture. In November 1980, the USGS calculated the aftershock hypocenters given in Table 4 during the first 32 min after the initiation of the rupture. Since QLARM distributes loss estimates about 30 min after a given earthquake, estimates of losses based on a line source (defined by the aftershocks), would have been distributed within about one hour of the main shock.

**Table 4.** Parameters listed by the USGS for the Irpinia main shock and the first three aftershocks that occurred within 32 min of the main shock (delay in third to last column). The distance of each aftershock from the initial rupture point (second to last column) allows an early estimate of the rupture length (last column) as the separation of the most distant aftershocks from each other.


The three aftershocks listed in Table 4 define an approximate direction of the rupture NW to SE. Therefore, in real time, the QLARM operator would have made the usual assumption that the aftershocks most distant from the initiation of the rupture give an approximate indication of the rupture length and direction. In this case, aftershocks 1 and 2 (origin times 18:52 and 19:04) were separated by 61 km. This length agrees with an M6.9 rupture [11,12]. That means it supports the hypothesis that

after 30 min the full length of the rupture was approximately defined as 61 km. Assuming that this was the case, a second estimate of the casualties, as given in the second row of Table 3, would have been distributed by QLARM within about an hour of the earthquake.

The final estimate of casualties (Figure 3) is based on a line source connecting the endpoints of the surface rupture (row three of Table 3) and the aftershock distribution as published years after the event [13–15]. This estimate would not have been available in real time but is given here as the best estimate of the reliability of QLARM alerts for losses in Italian earthquakes.

**Figure 3.** Map of estimated mean damage in the 1980 Irpinia epicenter area, calculated for a line source with M6.9, end points at 41◦ N/15◦ E and 40.355◦ N/15.515◦ E with occurrence at 19:35 local time. Each dot marks a settlement. The distribution of strong damage is seen better when the rupture is modelled as a line rather than a point (Figure 2).

QLARM also estimates numbers of affected people. We defined strongly affected people as those living in the area of intensity VIII+ because serious damage occurs in this area. The number of people in the area of intensity VI + VII were considered moderately affected because some damage occurs, and some casualties may result. The total number of affected people was defined as the sum of these two categories, that is, all in the area of intensities VI+ (Table 5).


**Table 5.** Estimates of numbers of affected people for the three types of earthquake source models of Table 3, and in three categories of shaking (intensities VI + VII, VIII + IX, and VI+).

#### **5. Discussion**

The loss estimates we have distributed over the last 17 years and presented here are not intended to be highly accurate and applicable to single settlements. They are intended to be order of magnitude assessments of the extent of disasters. Unknowns, such as local soil conditions, tend to average out when many settlements receive strong shaking. Therefore, loss estimates for large earthquakes are more stable than for small ones. Loss estimates for small earthquakes with relatively few fatalities are less reliable because the collapse of a single apartment building or school can kill 100 people, possibly doubling the number of fatalities. For example, on 31 October, 2002, a school collapsed in an M5.9 earthquake in Molise, Italy, killing 27 out of 28 reported fatalities.

The number of fatalities is taken as the best measure of the extent of an earthquake disaster, especially soon after the event. It is a number that is relatively accurate for most earthquakes after months once all the information has been gathered. The number of injured is more uncertain and often not given. Even more nebulous are economic losses.

Comparison of the reported numbers of fatalities with the theoretical ones in Table 3 is a measure of the quality of QLARM performance. It shows the estimates of the number of fatalities at 30 min, 60 min and after a year compared with final reported numbers. The result of the initial point source calculation (distribution with 30 min delay) is already acceptable, given that the maximum fatality estimate is 74% of the ultimate count (row 1 in Table 3). Based on the aftershock locations that would have become known within an additional 30 min, the approximate line source model for the rupture yields a range of numbers of fatalities that encompasses the observed number (row 2 in Table 3). This good agreement is achieved, even though rapidly calculated epicenters can be wrong by about 10 km [4], which means that the preliminary estimate of the rupture line is poorly defined.

The final and best source model of a line is defined by the aftershock distribution and surface ruptures published years later [13–15]. This final model gives the best agreement between calculated and observed fatalities, but it does not become available within an hour after the shock. It is, however, a measure of QLARM performance for Italy with final earthquake source parameters known. The three agreements in Table 3 are most encouraging because they indicate that the program QLARM yields correct estimates of fatalities in Italian earthquakes.

The hypothetically calculated number of injured matches the reported numbers surprisingly well (Table 3). In all models (three rows in Table 3), the minimum and maximum estimates of injuries encompass the reported number.

The history of casualty underestimates by news media is not known to us in the case of the 1980 Irpinia earthquake, but we assume it was similar to the cases documented [16]. Figure 4 shows the delay of assessing the size of the disaster in the case of the L'Aquila M6.3 earthquake on 6 April, 2009, compared to the mean value estimates by QLARM 22 min after the earthquake. The slow reporting of correct fatality numbers by media is not surprising because no information is flowing from regions of earthquake disasters for hours or even days. Even in the case of a small earthquake like in L'Aquila, it takes some time for the extent of the losses to become clear (Figure 4). This is more pronounced in larger disasters [16] as in the Wenchuan M8 and Kashmir M7.6 earthquakes that killed more than 87,000 people. In these instances, more than a week passed before the extent of the disaster became apparent. Given that the Irpinia earthquake's magnitude was intermediary between that of L'Aquila, Wenchuan and Kashmir, one has to assume that in a future Italian earthquake of M7±, there will be several days of fatality underestimates by the news media. The reports by PAGER and QLARM could correct this misunderstanding by highlighting the need of major rescue efforts.

**Figure 4.** Reports of fatalities as a function of time after the L'Aquila M6.3 earthquake. The average estimate by QLARM was correct and given after 22 min.

Initial epicenter errors can map into large errors in fatality estimates when the population present is concentrated in one spot [7]. However, in the center of Italy, this is a less severe problem because the population is distributed. The results by three models for the Irpinia source with increasing precision do not yield vastly different fatality estimates (Table 3). Nevertheless, in Italy, loss estimators must pay attention to the possibility of one of the larger metropolitan areas being affected.

Back projections of the rupture line source [17] and estimates of early warning [18] may become available in near-real-time. This will replace the need to rely on aftershocks to estimate the rupture direction and length. After the Irpinia earthquake, relevant aftershocks were recorded within about half an hour, but this is not always the case. Therefore, near-real-time back projections and early warnings will become important to increase the accuracy of fast loss estimates after earthquakes.

The Irpinia source was a complex multiple rupture. It is known that large and great earthquakes tend to be multiple ruptures since this was established for the M9.2 Alaskan earthquake of 1964 [19]. One might therefore ask how strong ground motion should be modelled for multiple ruptures. One answer comes from the strong motion record at right angles and at 43 km distance from the M7.2 Kalapana rupture in 1975. The aftershock area in 1975 was 50 km long and six separate sub-earthquakes were identified [20]. In Harvey, D. 1986 [20], Figure 2 demonstrates that pulses of seismic energy were emitted for more than 60 seconds with intervals as long as 10 seconds of no energy being released. The amplitudes of these pulses were not much larger than those of the M5.9 foreshock (Figure 2 of [20]), which means that, for engineering purposes, the Kalapana seismic radiation consisted of a sequence of pulses corresponding to earthquakes in the range of 6.0 < M < 6.5. The overall rupture, as measured by long period surface waves, however, indicated an M7.2 earthquake.

The complexity of the Irpinia earthquake must have similarly modified the local radiation of high frequency seismic waves. Nevertheless, the sum of the damage and the human losses is estimated correctly using a ground motion prediction equation for an M6.9 earthquake.

Admittedly, the size of the error bars for estimating casualties (minima and maxima in Table 3) are large. This is because minutes after an earthquake there are many poorly known parameters including location, depth, M, direction of rupture, length of rupture, energy propagation effects, local soil conditions, condition of the built environment and occupation rate of buildings. In spite of these numerous uncertainties, casualties and injured in the Irpinia M6.9 and L'Aquila M6.3 earthquakes are estimated correctly.

Satellite images could provide the strongest refinements of estimates of rupture location and extent. An example of this has been shown for the Bam earthquake [21]. In this case, interferometry could have shown that the rupture went straight through the city of Bam, while early estimates placed the epicenter 5 to 10 km west of the city. The difference in fatality estimates in this case was nearly two orders of magnitude. In Italy, the difference would not be that large because the population is more evenly distributed than in the area of Bam, Iran. Nevertheless, rapidly constructed interferograms that would define the crustal deformation due to an earthquake could help greatly in improving rapid loss assessments. For this to be possible, the necessary satellite passes have to become available without delay.

#### **6. Conclusions**

Rupture dimensions of disastrous earthquakes in Italy are not very long, only in the range of 20 to 80 km. Therefore, point source estimates of shaking, damage and casualties are reasonably reliable. Definitions of the direction and length of ruptures improve the loss estimates to a level that can be called excellent in the case of the M6.9 Irpinia earthquake. The correct estimates of casualties presented in this paper for Irpinia calculated in 2020 have also been achieved in near-real-time by QLARM for the M6.3 L'Aquila earthquake. This means that QLARM can be expected to correctly estimate casualties after Italian earthquakes within less than an hour. Since two groups, QLARM and PAGER, issue earthquake loss alerts that are similar and reliable, media, government and the general population should base their response to earthquake disasters on these estimates, which become available within less than an hour, instead of relying on the notorious underestimates by media that can last for weeks.

**Author Contributions:** M.W. has developed the concept and has performed the calculations. P.R. has researched and implemented the data used and made Figure 3. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research received no external funding

**Acknowledgments:** Dataset for population and buildings in QLARM for Italia was jointly developed with colleagues Sandra Hurter and Goran Trendafiloski. We thank S. Tolis for information on buildings in Greece and the reviewers for helpful comments, especially reviewer 1.

**Conflicts of Interest:** The authors declare there exists no conflict of interest.

#### **References**


© 2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).

### *Article* **Reconstruction as a Long-Term Process. Memory, Experiences and Cultural Heritage in the Irpinia Post-Earthquake (November 23, 1980)**

#### **Gabriele Ivo Moscaritolo**

Department of Social Science, Federico II University of Naples, 80138 Naples, Italy; moskari@hotmail.it Received: 26 June 2020; Accepted: 12 August 2020; Published: 15 August 2020

**Abstract:** Reconstruction after an earthquake is often seen as a material issue, which concerns "objects" such as houses, roofs, and streets. This point of view is supported by the mass media showing the work progress in the disaster areas, especially in conjunction with anniversaries. Rather, we should consider reconstruction as a complex social process in which cultural backgrounds, expectations, and ideas of the future come into play, without neglecting geological, historical, legislative, economic, and political factors. Combining oral history sources and archival records, the article shows the paths taken by two small towns among the most affected by the earthquake of 23rd November 1980 (Mw 6.9). These towns have made opposite reconstruction choices (in situ and ex novo) representing two classical and different ways in which human societies can face their past and think their own future. A careful analysis of these forty-year experiences, with a special focus on cultural heritage, provides useful indications for post-disaster reconstructions in which more attention to the process, and not just to the final product, should be paid.

**Keywords:** disasters; earthquake; reconstruction; cultural heritage; experiences; oral history; memory; 1980 earthquake

#### **1. Introduction**

The earthquake occurred on 23rd November 1980 has been one of the most disastrous seismic events in recent Italian history. It affected a large area in Southern Italy, destroyed dozens of towns, and there were 2735 victims, 9000 injured, and 394,000 homeless [1]. Over the last few decades, the media have recounted this event by emphasizing the central government's unpreparedness in managing relief efforts or by remembering the corruption and the wastefulness during the reconstruction phase. Moreover, many Italian scholars have concentrated their attention on political and economic aspects [2,3], especially in the area around Naples [4–6].

This study is part of another line of research, in which the experiences and memories of the affected populations have been investigated [7–11]. More specifically, it retraces the history of Sant'Angelo dei Lombardi and Conza della Campania (province of Avellino) (Figure 1)—two towns where the X MCS was reached [12,13]—which adopted opposite approaches to reconstruction. A "philological reconstruction" [14] of the old town center was the choice in Sant'Angelo dei Lombardi, whereas Conza della Campania opted for a new settlement rebuilt ex novo near the ancient center, which today has become an archaeological site. These special cases represent both future-oriented choices and two ways in which the past and cultural heritage can be preserved. The aim is to illustrate how a natural phenomenon interacts with human society and how different responses may arise from the same event. Furthermore, another purpose is to show the complex social process of reconstruction and how people after forty years evaluate and rationalize it. From this perspective, the 1980 earthquake is an extremely interesting case study, because the reconstruction act of law (Act. 219/81) granted much autonomy to

the local municipality and, after four decades, a broad spectrum of different choices and outcomes is observable.

**Figure 1.** Isoseismal lines of the 1980 earthquake and localization of the two studied towns (modified after Postpischl et al. [13]).

To fully understand the impact of an earthquake on human societies an ecological perspective is necessary. "The natural world and human societies are more easily understandable when they are considered as two systemic and complex realities, fully interactive with each other. They are the most strongly interactive with each other because they rest on the same material, physical, chemical and biological base" [15] (p. vi). Accordingly, "disasters occur at the intersection of nature and culture and illustrate, often dramatically, the mutuality of each in the constitution of the other" [16] (p. 24). Time is also a fundamental factor in understanding catastrophes, because the complex relationship between man and nature is historically constructed and it is based on short or long-duration social processes whereby human beings adapt to their environment [17]. Therefore, an approach capable of encompassing environment, culture, and history becomes essential. In this complex interaction, it is useful to consider the notion of "resilience", which is widely used in disaster studies. The term has received some criticism because diverse actors infuse the concept with diverse meanings [18] but an agreement on its definition may be very productive in this field [19]. Today, the most common definition is provided by United Nations Office for Disaster Risk Reduction (UNDRR): "The ability of a system, community or society exposed to hazards to resist, absorb, accommodate, adapt to, transform and recover from the effects of a hazard in a timely and efficient manner, including through the preservation and restoration of its essential basic structures and functions through risk management" [20].

From this perspective, it is interesting to consider how disasters affect tangible cultural heritage and, consequently, how people try (or do not try) to preserve it. In any area that has been settled for centuries, historic buildings and monuments tend to be a highly visible part of daily life. They embody the continuity of time between the generations and help define the genius loci, or spirit of place, of a settlement [21]. When a disaster occurs, the tangible legacy inherited from past generations can be damaged and at the same time, the cultural identity of a geographical locality is threatened. As Ian Convery et al. underline: "Disasters and catastrophic events can be seen as 'happenings' that

entangle people, place and their heritage, and disasters and displacement can leave people overcome by a 'loss of self' and a 'loss of place' [ ... ]. While the intangible cultural heritage of a community might be considered as less at risk from catastrophe, in extreme cases the loss of culture bearers, or dramatic shifts in society, can result in the loss of these heritage assets" [22] (p. 2).

We will see how two small towns with a thousand-year history have decided to rebuild their settlement and cultural heritage differently. After crucial choices, a long social process started, and the witnesses interpret it in the light of the present.

#### **2. Materials and Methods**

This study is based on both archival records and oral interviews. The archives are Archivio Storico Protezione Civile (ASPC), Archivio di Stato di Avellino (ASAV), Comune di Conza della Campania (CCC), and Comune di Sant'Angelo dei Lombardi (CSL). ASPC and ASAV allow us to reconstruct how the central state dealt with the impact of the earthquake. In particular, about 600 documents have been examined, concerning both relief operations and the emergency structure that was organized in the following months [23–40]. The local archives (CSL, CCC) show how local authorities discussed and then planned the material reconstruction of the towns. Here, about 240 documents have been consulted, including scripts of council meetings, reconstruction plans, and maps [41–58]. Additionally, oral testimonies have been used. They provide important insights into the affected populations' point of view [59]. In particular, the study of memory can help us to understand what are the reasons behind important choices, how these are interpreted after 40 years, and how the whole reconstruction process influences both the material circumstances and the lives of populations. All the interviews have been collected by the author between 2014 and 2017 [60,61]. Witnesses belong to different generations and social classes: there are "institutional" people (mayors or municipal administrators), adult residents in 1980, and the new generations (born after 1980, but to whom memories have been transmitted) (Table 1). Contact with the witnesses took place in different ways. In some cases, the support of municipalities and local associations was central, in others, personal knowledge networks have been activated. The use of multiple channels to know new witnesses allowed us to reach different points of view and experiences. In general, people told their stories with pleasure, except in some cases where they did not want to speak about the evening of 23rd November. This is a very significant fact, as it is a sign that for someone the trauma has not yet been worked out. The interviews were videotaped and the transcriptions in original language are available upon request. Some of them are also available on the Multimedia Archive of the Memory (Archivio Multimediale delle Memorie) [62], hosted by the Department of Social Sciences at the University of Naples "Federico II".




**Table 1.** *Cont.*

#### **3. Results: Impact, Choices and Experiences**

#### *3.1. The Earthquake and Its Impact*

"I remember a beautiful day... with a hot sun and a crowded square... full of people with children" says Rosanna. The 23rd November 1980 was an unusually sweet day, and this is a leitmotiv in the collective memory of witnesses. After this pleasant picture, many people use terms such as "apocalypse" or "end of the world" to indicate the sudden impact and effects of the earthquake. In the words of Romualdo: "I heard a noise... terrible... of irons... an explosion... and instinctively I headed for the exit... but I realized that the stairs were beginning to writhe ... the building collapsed on the other floors, and then the door collapsed on me... I could not go back into the house and I was in that condition overnight" (Romualdo R.). The interruption of roads and communication lines, the delay in the arrival of reliefs, and the absence of a civil protection plan were the causes that amplified the tragedy [24]. The final toll was 2735 victims, 9000 injured, and 394,000 homeless; 687 municipalities were affected, including 37 declared "devastated", 314 "seriously damaged" and 336 "damaged" [63].

After the first moments of shock, people and communities faced different situations. Before the earthquake, Conza della Campania retained its original medieval configuration of narrow streets and closely-packed houses. These buildings collapsed in a tragic domino effect becoming a pile of stones and sand. Destruction reached 95% of the settlement (Figure 2). There were 184 dead and first aid came from the inhabitants themselves. Hence, the population abandoned the hill on 24th November, found shelter in a construction site located down the valley, and here spent the first months. "Fortunately, that building was able to accommodate many people [ ... ] we were really very crowded, but safe" remembers Luigi. The availability of a safe building to house the survivors allowed people to overcome some initial difficulties, such as the removal of rubble and the construction of temporary lodging. In the following days and months, the situation improved, thanks to the province of Bologna, which provided hundreds of volunteers and means to deal with the emergency [40].

The old city center of Sant'Angelo dei Lombardi also retained a medieval configuration. After the quake, it became a pile of rubble but most of the 432 deaths occurred in the "new" buildings, those that had arisen since the 1960s around the main square. These ones did not always comply with anti-seismic standards and collapsed generating the well-known pancake effect (Figure 3). "You could touch the roof of all of these buildings with your hands... they had become like an accordion" recalls Carmine. Compared to Conza, the situation was complicated, due to both the larger devastated area and the lack of the means to remove the reinforced concrete. There was no immediate availability of facilities to accommodate people, and the survivors spent the first few days in different ways as in

their car or hosts by relatives in other towns. Then, the situation was brought under control thanks to the intervention of the volunteers from the Regione Toscana, and from the Provinces of Brescia and Pesaro-Urbino, who set up camps for homeless [36,37].

**Figure 2.** Effects of the earthquake in Conza della Campania (Courtesy of Pro Loco Compsa).

**Figure 3.** The earthquake in Sant'Angelo dei Lombardi. On the background, the "pancake effect" (Courtesy of Michele V.).

Thanks to the famous speech by President Sandro Pertini, and to the headlines of the Italian press, the devastating impact of the eartquake had a global echo, and economic aid came from all over Italy and other nations. However, while the central state and rescuers were still dealing with the emergency, local populations, experts, and politicians began to debate the future reconstruction.

#### *3.2. A Persistent Dilemma: Reform vs Continuity*

As noted by Ian Davis and David Alexander [21], this is the first planning dilemma that authorities had to face after a disaster. Post-seism destruction certainly creates a "window of opportunity". On the one hand, this is an occasion to change what was wrong in the past, on the other it can generate the desire to restore the old world remembered with nostalgia. Likewise, within the post-1980 debate, we can distinguish these two opposite positions. "Reformers"advocated the relocation of whole towns closer to the main roads continuing a trend that had already started before the earthquake. However, "conservers" criticized the relocation, because it was not in harmony with the agricultural vocation of the countryside, and would not have allowed the recovery of the historical-artistic heritage of the old towns. These two options, but also various intermediate solutions, could be realized thanks to both the possibilities offered by the reconstruction law and the huge amount of funds allocated. In May 1981, the government issued Act. 219, based on two keywords: "reconstruction" and "development". The aim was to "modernize" the affected areas, still considered in a state of backwardness. More precisely, the article 27 reads: "Rebuilding takes place in the area of existing settlements and, if there are geological, technical and social reasons for it, in the municipal area as a whole. It can also be carried out by means of extensions, completions and adaptations, technical and functional, or by means of new works deemed necessary for the reorganization of an area and for its economic and social development". All the choices took into account the Progetto Finalizzato Geodinamica—CNR, the first major national project for seismic risk assessment. This programme produced maps of seismicity and seismo-tectonics in Italy before the earthquake, and carried out surveys of damage and the potential risk to the stricken towns from seismic sources afterwards. In particular, the most important activities were focused on the production of the Structural Model of Italy, the Neotectonic Map, the Seismic Catalogue, the Atlas of Isoseismala for the largest historical events, the Seismic Hazard Map, the National Seismic Zoning, the Guidelines for seismic risk mitigation of ancient buildings, and the microzonation investigations in the epicentral areas of the 1976 Friuli and 1980 Campania and Basilicata [64,65].

In Conza della Campania the choice of relocation was shared by a large part of the population. Various reasons emerge from the field research:


the notion of building, commercial and artisanal expansion along the slopes going down towards the valley" (Felice I.).

Differently, the townspeople of Sant'Angelo intended to restore the lost past. This choice was possible thanks to the geological investigations which considered the area of the ancient center suitable for reconstruction [68]. Various reasons can be identified:


Therefore, starting from various reasons, these two small towns have decided to rebuild their settlement differently. In both cases, the tangible cultural heritage and the ancient history of the centers have played an important role in the decisions.

#### *3.3. Preserving Cultural Heritage*

Historical monuments and buildings, but also modern structure or landscape features, are often elements that embody the spirit of a place, or genius loci. They help to create a sense of belonging and a special connection between people who identify them as part of their own identity [69]. For these reasons, cultural heritage protection and restoration are often among the immediate priorities of recovery from disaster, although they are expensive, complex, and time-consuming processes. For example, the earthquakes that hit Italy in 1997 (in the regions of Umbria and Marche) damaged about 1200 religious buildings, and a large recovery project was set up in the aftermath [70]. In the post-1980 reconstruction debate, the recovery of historical buildings was central and each town headed for different choices [71,72]. Both of the case studies discussed here represent two ways of preserving and celebrating ancient origins, although they pursue two opposite choices for the future.

Sant'Angelo dei Lombardi became the seat of the Plan Office of Soprintendenza (Ufficio di Piano) and a strong collaboration between local scholars and from all over Italy was created. They opposed the demolitions of the old town center and established the "Cultural and Environmental Heritage Service" with the task of coordinating recovery initiatives [43]. The "Earthquake archaeologists", as the press nicknamed the group, created a "Village of cultural heritage" and requested funding for interventions in the historic center. After the approval of the Act. 219, the Technical Commission of Cultural Heritage was formed, and it worked on the preparation of the Recovery Plan [41,46]. The aim was to consider the old town center as a whole, and not as a mere sum of buildings [44]. This conception was not applied in other Recovery Plans and, therefore, in Sant'Angelo, the technical standards were established for the specific case. Moreover, among the aims of the Plan, there were both

the resettlement of the population and the start of economic activities. The restoration of the entire old town center took many years compared to the new homes. The overall time was approximately 20 years (Figure 4).

**Figure 4.** The cathedral of Sant'Angelo dei Lombardi, before (above) and after (below) the earthquake.

In comparison to Sant'Angelo, the recovery of the ancient *Compsa* had different purposes. On the one hand, the resettlement of the population was not planned, as a new town close to the main road would be built. On the other, there were Roman archeological finds to bring to light, and no damaged buildings to restore. Professor Corrado Beguinot (School of Architecture—"Federico II" University of Naples) designed the Recovery Plan which was approved in September 1982. The project considered the old settlement an economic and cultural asset, as supported by the most recent debate on the safeguarding and protection of historic centers. For this reason, interventions and restorations for tourist and cultural activities would have been scheduled. After the removal of debris, excavation and restoration campaigns were planned to create the archaeological park where an antiquarium (a sort of museum) and a seismological center would be built. The park was inaugurated in 2003 (Figure 5) [71].

**Figure 5.** In the foreground, the "new Conza". On the hilltop, the archeological park (Courtesy of Pro Loco Compsa).

#### *3.4. After the Choices, Life Continues*

Reconstruction after an earthquake is not a mere material issue concerning "objects" such as houses, roofs, and streets. To fully understand its outcomes, we should consider it as a complex social process, rather than just observing the final product. Thus, in order to illuminate the relationship between people and the environment, we have to study the various stages that the populations go through while waiting for the completion of the work. These phases constituted an important part of their own experience and help us understand how people adapt to their environment, especially after the sudden transformations caused by a major earthquake. As Sara Zizzari has shown in her study—where she combines the L'Aquila post-earthquake urban transformations with oral sources—the path to returning home is a complex social-spatial issue, which has consequences for both individual and collective paths [73]. In the cases presented here, the implementation of the plans was the starting point of a long path.

After the first months spent in the construction site, the inhabitants of Conza lived for twelve years in a valley settlement: "The urbanised area was built by the Province of Bologna according to really valid urban criteria... It really was a model of extraordinary urban cohabitation. All the spaces were well arranged... the prefabricated homes, although small, were comfortable... you got a sense of privacy,

of intimacy, in short, of family, not separated, because they were contiguous and therefore in a way they restored the downhome dimension of the old town, of the neighborhood" (Luigi L.). This positive memory is largely shared among townspeople. The settlement allowed people to be as close together as they had been in the old town center. Gerardina, in turn, remembers how the condition of being "all earthquake victims" contributed to strengthening ties: "It was good in the prefabricated homes... this was a good experience... because we lived closer to each other... we were all equal and being all equal is important... there were no rich, there were no poor" (Gerardina M.). Unfortunately, after this good period, the transfer to the new town was traumatic. The "new Conza" had an urban structure very different from the old city (Figure 5). This was a long-lasting cause of disorientation for the population. As Antonia recalls: "This is a dark moment in my mind, the move to the new Conza della Campania, because at that time Conza was not a town, it was a group of houses where there were no facilities for the community... the square was not a square, there were no memories associated with those places, there was nothing for us" (Antonia P.). Since 1992, the appearance of the town has changed a lot, as new urban furniture has made the center more livable. For the younger generations, it is certainly easier to adapt to the new places, but for those who used to live in a different spatial context, the "old" Conza remains a world remembered with nostalgia.

As we have seen (Section 3.1), in Sant'Angelo there was no immediate availability of facilities to accommodate people and even establishing temporary settlements was a complicated matter. The population was larger than Conza, and they did not want to leave the destroyed town center. Thus, temporary housing sprung up in various available areas around the ruins, creating a patchwork spatial pattern. This sudden change led to a sense of displacement among the citizens, who were accustomed to a social life concentrated around the main square and the town center. Tony's words show this lasting sense of disorientation: "For many years, this patchwork layout caused us to lose the centrality of the agora, of the main square ... and perhaps we are still bearing the consequences... the square that is usually the heart of the community, where you meet, where you argue, where you walk, where you discuss... it was empty for many years... it was the ghost of the town's main square... in the evening there was nothing at all... you could meet at one or two bars, located within these settlements or near them... for too long a period... settlement at the margins of the town led to the loss of the sense of community" (Tony L.). If in the case of Conza there are well-defined stages that the population has gone through, the transition to the "new" Sant'Angelo has been more gradual. Here, the intent was to recover the destroyed old town, to preserve its artistic and cultural identity, and to allow the resettlement of the population. Of course, restoration of ancient buildings is a time-consuming process and most of the population, after spending about fifteen years in prefabricated buildings, preferred to go and live in the new buildings at the edge of town. As Tonino underlines: "When the earthquake occurred, the historic center of Sant'Angelo was almost empty. Indeed, there were very few deaths in the historic center. People were resettled in expansion areas... this means that those whose house had collapsed in the expansion area preferred to return to the expansion area and to opt to have their home in the historic center as a second residence, because its construction would take much longer" (Tonino C.). Thus, today we can distinguish between the old part, which is well reconstructed but underpopulated, and the fragmented outskirts, where most of the inhabitants live [51].

#### **4. Discussion**

In their book, Christof Mauch and Christian Pfister recall the notion of "societies as weaving daily tapestries" [74] (p. 6). Following this metaphor, a disaster is "a gash or a sharply discordant thread suddenly introduced into the pattern". Accordingly, a historical perspective forces analysts to see "how a society repairs/reweaves itself and moves on. In many cases, the tapestry takes off in a dramatically different direction, with new colors and designs" [75] (pp. 1–2). This fascinating idea underlies the study presented here. Forty years after the 1980 earthquake, it is possible to adopt a long-term perspective, retrace the paths taken by the affected communities, and to show how different responses may arise from the same event. Moreover, from a memory studies perspective, forty years represent

a significant time frame because "after forty years those who have witnessed an important event as an adult will leave their future-oriented professional career, and will enter the age group in which memory grows as does the desire to fix it and pass it on" [76] (p. 36). As we have seen, the witnesses' stories allow us to fully understand the upheavals caused by a great earthquake and illuminate how important decisions are made, decisions having an impact both on the environment and on the lives of populations. In other words, the memory perspective helps us to deeply investigate the complex relationship between human beings and their environment.

Sant'Angelo dei Lombardi and Conza della Campania represent two classical and different ways in which, after a great calamity, people can face their past and think their own future. The Italian sociologist Alessandro Cavalli proposed three ways whereby communities deal with the experience of space-time discontinuity. These are "ideal types", an idea-construct of social phenomena that do not fully correspond to reality, but are meant to stress certain elements common to most cases of the given phenomenon [77]. These types are the "re-localization" (the move of the entire town), the "philological reconstruction" (which aims to restore the pre-disaster state), and the "selective reconstruction" (which preserves some symbolic elements of the past) [14]. The model of re-localization, which concerns the case of Conza, is a sort of "year zero model", because it represents a real rebirth for the affected communities. In this case, the breaking event is celebrated in order "not to forget", but also to symbolically mark the start of the new course. In some cases, the past may be removed. However, this does not represent the case of Conza, as the town's ancient history is now preserved in the archaeological park, an open-air museum where the pre-quake memory has been "frozen". The case of Sant'Angelo's old town center corresponds to the "philological reconstruction", which aims to restore the past from where it left off. This choice reflects the desire to reclaim both lost time and space but, in this possibility, there is also an attempt to remove the disastrous event and to delete the element of discontinuity.

Both in the "ideal types" by Cavalli and in our studied cases, tangible cultural heritage plays an important role, as buildings and historical monuments are among the elements that contribute to create the sense of a place. This is Tony's opinion on the reconstruction of Sant'Angelo: "The choice was fundamental, the historic centre where it was, even if some mistakes were made [...] I think so... both the town as a whole and the old town centre; thanks to the choice to rebuild as it was, the mayor earned the Zanotti Bianco prize... I have shared and still share this choice today... I am in love with the historic centre" (Tony L.). However, as pointed out above, the reconstruction process is not a mere material issue. Rather, it is a complex social process involving many aspects of community life. For example, the choice to restore the past may also include the desire for a cohesive community. In the words of Tonino: "The story is interpreted in a certain way... as one of successes... that are possibly measured on the 'material' reconstruction... but as regards the 'spiritual' reconstruction, so to speak... I think that Sant'Angelo stopped existing on that exact day... in the sense that... there are still ruins" (Tonino C.). Thus, in this case, the desire to get back the lost past seems to have been partially fulfilled.

Otherwise, the old center of Conza has changed its meaning, as it has become an open-air museum from an inhabited place. Thus, while a tourist can imagine ancient civilizations by observing the remains of the ancient Roman and medieval *Compsa*, the inhabitants have different sensations. For some, the hilltop has become a place of death and they have had difficulty returning over time. For others, like Domenico, there is the pleasure of being a tourist guide for his friends, but also the sadness of not seeing the places of youth anymore: "Sometimes I go there... friends come and I take them to see... I bring them but when I get there... the heart suffers" (Domenico T.). Finally, Antonia, born after 1980, during her visits imagines life, stories and places transmitted by photos and family stories: "I imagine these narrow streets made of stone, these houses... always full of life, of people with their coming and going because the cars could not get the hilltop, so people in their daily lives gave life to the town because they went back and forth to do the daily chores... I imagine it as a coloured town" (Antonia P.).

What lesson can we learn from these stories? Does studying the experiences of communities affected by disasters have a purely historical interest? Or can we use this knowledge for future experiences? What is the role played by people's memory?

According to Christian Pfister, "natural hazards are of course retained in memory if they recur frequently, and the more frequently they occur, the more likely people are to anticipate them and to try to develop adequate adaptive strategies, which are always the result of learning processes and which can take different forms" [78] (p. 4). Consequently, the memory of disasters would be able to develop a "culture of disasters" whereby human societies adapt to risky environments [79]. However, this adaptation process is not obvious because "the manner, scope and thus benefit of this implicit or explicit 'learning' varies greatly and depends on epoch and culture. This variation reveals the role played by history and culture in the learning process" [80] (p. 76).

Starting from historical knowledge, it may be possible to draw lessons that can be useful for living with environmental risk. In other words, stop building vulnerable settlements, being able to manage future emergencies, and planning reconstructions from a long-term perspective. All these actions should take into account the social dimension of the disaster and not only the material one. As the geographer Robert Geipel pointed out: "Disaster and reconstruction are incisive events in the life of the individual and group [ ... ]. Planning that follows only laws of a technical rationality would endanger the already injured identity" [81] (p. 152). For example, our cases inform us about the importance of maintaining social/spatial relations as similar as possible to the pre-disaster state, in order to favor the social cohesion after a traumatic experience. Furthermore, the importance of the recovery of cultural heritage is certainly a fundamental aspect of the reconstructions, as it allows establishing connection and common reference point between generations. However, a "spiritual reconstruction", which aims to repair the social ties of the affected community, should also be pursued. In conclusion, we should start from people's stories, because "local actors play such a crucial role in the transmission of social memory. We lack stories that can translate knowledge into a renewed sense of place and cultural identity. Local communities [ ... ] teach us about the possibility of living differently on (and with) an unstable earth" [82] (p. 77).

#### **Funding:** This research received no external funding.

**Acknowledgments:** First of all, I would like to thank the people who wanted to tell their story. Without their voice, this work would not have been possible. Sincere thanks go to the archives staff who made the research possible. Finally, I would like to express my deep gratitude to Gabriella Gribaudi for her precious teachings during my studies and research.

**Conflicts of Interest:** The authors declare no conflict of interest.

#### **References and Notes**


© 2020 by the author. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).

### *Communication* **Photographic Reportage on the Rebuilding after the Irpinia-Basilicata 1980 Earthquake (Southern Italy)**

**Sabina Porfido 1,2, Giuliana Alessio 2, Germana Gaudiosi 2, Rosa Nappi 2,\*, Alessandro Maria Michetti <sup>3</sup> and Efisio Spiga <sup>4</sup>**


**Abstract:** This paper aims to present, through a photographic reportage, the current state of rebuilding of the most devastated villages by the earthquake that hit the Southern Italy on 23 November 1980, in Irpinia-Basilicata. The earthquake was characterized by magnitude Ml = 6.9 and epicentral intensity I0 = X MCS. It was felt throughout Italy with the epicenter in the Southern Apennines, between the regions of Campania and Basilicata that were the most damaged areas. About 800 localities were serious damaged; 7,500 houses were completely destroyed and 27,500 seriously damaged. The photographic survey has been done in 23 towns during the last five years: Castelnuovo di Conza, Conza della Campania, Laviano, Lioni, Santomenna, Sant'Angelo dei Lombardi, Balvano, Caposele, Calabritto and the hamlet of Quaglietta, San Mango sul Calore, San Michele di Serino, Pescopagano, Guardia dei Lombardi, Torella dei Lombardi, Colliano, Romagnano al Monte, Salvitelle, Senerchia, Teora, Bisaccia, Calitri and Avellino. Forty years after the 1980 earthquake, the photographs show villages almost completely rebuilt with modern techniques where reinforced concrete prevails. Only in few instances, the reconstruction was carried out trying to recover the pre-existing building heritage, without changing the original urban planning, or modifying it. We argue that this photography collection allows to assess the real understanding of the geological information for urban planning after a major destructive seismic event. Even more than this, documenting the rebuilding process in a large epicentral area reveals the human legacy to the natural landscape, and our ability, or failure, to properly interpret the environmental fate of a site.

**Keywords:** 1980 Irpinia-Basilicata earthquake; photographic reportage; rebuilding

#### **1. Introduction**

The earthquake of 23 November 1980, more commonly known as the Irpinia-Basilicata earthquake, was the strongest seismic event to hit the Southern Apennines in the last 100 years. It was characterized by magnitude Mw = 6.9 and intensity Io = X Mercalli Cancani Sieberg (MCS) scale and/or X Environmental Seismic Intensity 2007 (ESI-07) scale [1–4]. It was felt throughout Italy, from Sicily in the South, to Emilia Romagna and Liguria in the North (Figure 1). It caused devastating effects in over 800 localities distributed in the regions of Campania and Basilicata with a total of 75,000 houses destroyed and 275,000 seriously damaged. The number of victims was about 3000, with 10,000 injured people. Several municipalities distributed in the provinces of Avellino, Salerno and Potenza were almost totally destroyed, since the local felt intensity was I > VIII MCS. In the Campania region, the level of damage of 542 towns was classified as follows: 28 towns destroyed, 250 seriously damaged, 264 damaged; in the Basilicata region, 131 municipalities were classified of which nine were destroyed, 63 seriously damaged and 59 damaged [5–7].

**Citation:** Porfido, S.; Alessio, G.; Gaudiosi, G.; Nappi, R.; Michetti, A.M.; Spiga, E. Photographic Reportage on the Rebuilding After the Irpinia-Basilicata 1980 Earthquake (Southern Italy). *Geosciences* **2021**, *11*, 6. https://doi.org/10.3390/ geosciences11010006

Received: 17 November 2020 Accepted: 21 December 2020 Published: 25 December 2020

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The earthquake also caused several striking effects on the natural environment including extensive coseismic surface faulting, observed between Lioni (Avellino) and San Gregorio Magno (Salerno) [8–18]. Moreover, over 200 landslides occurred, the most devasting hit the territories of Calitri in the urban center [11,19–22], Caposele (Buoninventre landslide) and Senerchia (Serra d'Acquara landslide) (Figure 2) [11,23]; also, widespread soil fracturing was observed, and minor liquefaction effects [24–27]. Furthermore, the coseismic faulting of the regional karst aquifer induced important hydrological variations in the springs of Caposele and Cassano Irpino [25] (Table 1).

Forty years after the 1980 earthquake, we decided to record, through a photographic reportage, the state of the rebuilding, the urban changes that the earthquake had induced mainly in the epicenter and near field areas. This study represents a realistic documentation of what has been achieved over all these years, even with the considerable state economic funding, and the resilience of each community [28]. The study of the various localities portrayed is accompanied by a detailed bibliography starting from 1981 until today.

**Figure 1.** Isoseismal Map of the 23 November 1980 Irpinia-Basilicata earthquake [1].

**Figure 2.** Environmental effects induced in the epicentral area by the 23 November 1980 Irpinia-Basilicata earthquake [21]. The Ortophoto image from Google Earth.

**Table 1.** The table contains the visited localities, their geographic coordinates and MCS and ESI intensity with the most significant environmental effects observed after the 1980 earthquake (SF surface fault; F fractures, L landslide, SC Soil Compaction, HC Hydrological Changes, LQ Liquefaction) [1–3,11,12,14,19–23,25–27].



**Table 1.** *Cont.*

#### **2. Discussion**

The photographic journey, carried out in the last five years, includes the documentation of the villages almost completely destroyed or seriously damaged (Figure 3), with damage levels evaluated at I ≥ VIII MCS, Table 1): Castelnuovo di Conza (Figures 4–9), Conza della Campania (Figures 10–18), Laviano (Figures 19–22), Lioni (Figures 23–28), Santomenna (Figures 29–33), Sant'Angelo dei Lombardi (Figures 34–39), Balvano (Figures 40–43), Caposele (Figures 44–47), Calabritto-Quaglietta (Figures 48–53), San Mango sul Calore (Figures 54–58), San Michele di Serino (Figures 59–65), Pescopagano (Figures 66– 70), Guardia dei Lombardi (Figures 71–74), Torella dei Lombardi (Figures 75–79), Colliano (Figures 80–85), Romagnano al Monte (Figures 86–89), Salvitelle (Figures 90–94), Senerchia (Figures 95–99) and Teora (Figures 100–104) [1,2,4,7,29]. In some cases, we also took into account the preliminary seismic microzonation maps drawn up by the PFG of CNR (Finalized Geodynamic Project (PFG) of the National Research Council (CNR), the first major national project for seismic risk assessment and reduction), which provided useful indications for reconstruction [29]. Moreover, two others towns, Bisaccia (Figures 105–108) and Calitri (Figures 109–114), although characterized by a lower intensity (I = VIII MCS), have been added to our study due to the different pathways for reconstruction, despite having both serious hydrogeological problems. Bisaccia has been often affected by landslides, due to its geological formations, mostly made by conglomerates resting on varicolored clays; indeed it was among the villages admitted to consolidation as early as 1917. Nowadays there are two Bisaccia villages: the old, ancient village recovered around the ducal castle and the new Bisaccia of the 'Piano di Zona', the latter almost completely rebuilt according to the urban plan drawn up by the architect Aldo Loris Rossi. Regards Calitri, it was built on the top of a hill made of sandstone and conglomerate rocks, with the middle-lower slopes made of intensely tectonized clay-rich units; therefore, it was often affected by landslides. A great landslide occurred due to the 1980 earthquake, approximately 850 m long and up to 100 m deep; it had terrible consequences on the urban and road structure of the village [19]. Moreover, other significant coseismic environmental effects occurred such as fracturing and liquefaction phenomena. Further landslides occurred in Calitri due to the 1694, 1805, 1910 and 1930 earthquakes [1,7,11,21,22,29–31]. We also added the Avellino city

(Figures 115–119), because it is one of the largest cities in Campania, with level of damage I = VIII [32].

In this photographic reportage, we have deliberately chosen not to reproduce the tragic images of the catastrophe, destruction, death of the places visited, that characterized all the front pages of the newspapers of the time (e.g., Figure 3) [33]. We have chosen to show the current, rebuilt urban centers.

**Figure 3.** The front page of "Il Mattino" newspaper (26 November 1980) transformed by Andy Warhol into a pop art manifesto [33].

We analyzed the reconstruction through the representative buildings as the churches, the town halls, the sports centers. In some cases, there are pictures of temporary villages, generally made of wooden houses, where people lived for many years waiting for the final accommodation, now used for local tourism. Almost all the villages were rebuilt in the same place despite some of them were completely razed to the ground not only by the earthquake but also by bulldozers that destroyed everything, even more than necessary.

The buildings of the old urban centers were mostly made in natural stone or baked bricks with poor mortar and wooden floors while the rebuilding involved reinforced concrete buildings, earthquake-proof. The new urban centers were rebuilt with wide roads and outsized areas for new housing compared to the current number of inhabitants, that over the last forty years has decreased dramatically, especially for the most internal areas.

As mentioned above, all of the villages affected by the earthquake were rebuilt in situ, with the exception of Conza della Campania, Romagnano al Monte and Bisaccia. For Conza della Campania, a town almost completely destroyed by the earthquake with a high number of deaths (184 victims), the political choice of the urban center relocation prevailed, supported also by the results of the numerous geological surveys some of which also emphasized local amplification phenomena due to morphology. Indeed, Conza was built on two small hills made by clay and sandy clay in the lower part, conglomerates with sands and sandstones in the middle part, and conglomerates of middle-low resistance in the upper part. The 1980 earthquake induced in this village several different environmental effects such as landslides, ground cracks and ground settlement. Moreover, this choice was also due to the historical memory of the destruction suffered by the community in past earthquakes (1466, 1517,1694, 1732 and 1930 seismic events) [7,18,29–31,34]. At present two Conza villages f coexist: the ancient village recovered and enhanced with the creation of an archaeological park that preserves the remains of the ancient Roman 'Compsa'; and the new Conza, built in Piano delle Briglie, 4 km far from the original nucleus where the topography of this flat area ensured safer conditions. This is a modern village characterized by earthquake-proof houses and wide roads, designed by the architect Beguinot of the University of Naples, [35–38].

Even for Romagnano al Monte, a small village in the Salerno province with only 370 inhabitants, located 650 m a.s.l., overlooking the gorges of the Platano River a few kilometres from the epicentre of the 1980 earthquake, the political decision to relocate prevailed. The main reason was due to the declared inhabitability of 446 residential units, after the earthquake, that also caused the collapse of some churches and heavy damage to the town hall. The geomorphological and geological assessment, that accentuated the seismic shaking, also contributed to the choice in the reconstruction process. The old town, in fact, is located at the highest point on the ridge and along the slopes are frequent phenomena of rock fall caused by the high degree of fracturing bedrock.

The village was evacuated and abandoned becoming a "ghost town" [39]. The new town was located in Ariola, 2 km from the old center, in a less panoramic position, but providing more convenient access for the inhabitants.

More complex and longer is the history of Bisaccia's relocation. The village located at 860 m a.s.l., was affected by landslides due to the geological conditions on which it stands and was already destroyed by historical earthquakes (1694 1732, 1930 and 1980 seismic events). These aspects have heavily conditioned its rebuilding. The 1980 earthquake, once again highlighted the territory's extremely unstable conditions, so the Municipal Administrations opted for the reconstruction of the village in another site, more stable from a geological point of view, called "Piano di Zona", which was already identified in a previous urban planning, following the 1930 earthquake [7,40,41].

As a matter of fact, there are currently two Bisaccia towns: the old one, an ancient village recovered around the ducal castle; and the new Bisaccia of the Piano di Zona, the latter almost completely rebuilt according to the urban planning drawn up by architect Aldo Loris Rossi [42].

About the other villages we can say that among those among those which have decided to rebuild in situ, some of them have chosen the recovery or rebuilding of the old urban center, respecting the original architectural design, combined with new buildings in the expansion areas.

Among these we mention certainly Sant'Angelo dei Lombardi, with a careful reconstruction of the historical centre and the Abbey of Goleto (Figure 36) [7,29,31,43]; Calitri despite the historical large landslide triggered by the earthquakes (Figure 110) [7,29]; Guardia dei Lombardi (Figure 73) [7,29]; Torella dei Lombardi [7,29];(Figure 75); Caposele [29,34]; Lioni (Figure 28); Balvano (Figure 41); Pescopagano (Figure 66); and Quaglietta (Figure 53), whose medieval village has been recovered to transform it into an "albergo diffuso" ("scattered hotel") for tourism purposes [34,44].

Even Senerchia, which has been currently rebuilt, tries to recover the remaining houses of the ancient village built on the solid calcareous substratum (Figure 98) [7,29,34]. In all the other villages the new buildings are predominant with some valuable innovative edifices such as the town hall of Lioni (Figure 25), a modern and functional building realized by the architect Verderosa, or in Balvano where the artists Boffo and Eibl designed the houses, or architectural structures often in contrast with the original planning of the village (Figures 42 and 43).

Unfortunately, in many cases during the rebuilding process the identity of Apennine villages such as Laviano (Figures 19 and 22), San Michele di Serino (Figure 62), Castelnuovo di Conza (Figure 5), Santomenna (Figure 30), where the new buildings prevail over the old ones, was lost, becoming only "rebuilt villages".

**Figure 4.** Original map of the seismic microzonation of Castelnuovo di Conza according to [29].

**Figure 5.** Castelnuovo di Conza: overview of the new village completely rebuilt after the1980 earthquake (photos by [35,36]).

**Figure 6.** Castelnuovo di Conza: detail of the new village completely rebuilt after the1980 earthquake (photos by [35,36]).

**Figure 7.** Castelnuovo di Conza: the new sports hall (photos by [35,36]).

**Figure 8.** Castelnuovo di Conza: Temporary village, consisting of wooden chalets, built immediately after the 1980 earthquake and still used today (photos by [35,36]).

**Figure 9.** Castelnuovo di Conza: detail of new reinforced concrete buildings (photos by [35,36]).

**Figure 10.** Original map of the seismic microzonation of Conza della Campania according to [29].

**Figure 11.** Conza della Campania: overview of the old village destroyed by the 1980 earthquake (photos by [35,36]).

**Figure 12.** Conza della Campania: old village with ruins of houses after the 1980 earthquake (photos by [35,36]).

**Figure 13.** Conza della Campania: old village with houses rebuilt after the 1980 earthquake (photos by [35,36]).

**Figure 14.** Conza della Campania: old village with the Archaeological Park realized a few years ago for the tourists (photos by [35,36]).

**Figure 15.** Conza della Campania: detail of the Archaeological Park (photos by [35,36]).

**Figure 16.** Conza della Campania: temporary village, consisting of wooden housing, built immediately after the earthquake of 1980 and now almost completely abandoned (photos by [35,36]).

**Figure 17.** Conza della Campania: new village with the new Cathedral "Concattedrale di Santa Maria Assunta" in the center of village built after the 1980 earthquake (photos by [35,36]).

**Figure 18.** Conza della Campania: panoramic view of the new Conza built in Piano delle Briglie locality, 4 km far from the original nucleus of the old Conza (photos by [35,36]).

**Figure 19.** Laviano: the village completely rebuilt after the 1980 earthquake (photos by [35,36]).

**Figure 20.** Laviano: the new "Chiesa Madre" (photos by [35,36]).

**Figure 21.** Laviano: the new Town Hall of Laviano (photos by [35,36]).

**Figure 22.** Laviano: Piazza della Repubblica (photos by [35,36]).

**Figure 23.** Lioni: one of the first buildings built in 1985, the "Bergamo condominium" is in reinforced concrete, built thanks to the solidarity of the inhabitants of Bergamo (Northern Italy) (photos by [35,36]).

**Figure 24.** Lioni: a detail of the "Bergamo condominium", the recent murales was done to remember the solidarity of the people forty years after the catastrophic earthquake (photos by [35,36]).

**Figure 25.** Lioni: part of modern Town Hall built by the architect A. Verderosa (1984–1994) (photos by [35,36]).

**Figure 26.** Lioni: modern bus station (photos by [35,36]).

**Figure 27.** Lioni: the new sports facilities (photos by [35,36]).

**Figure 28.** Lioni: restored Church and bell tower of S. Maria Assunta (photos by [35,36]).

**Figure 29.** Santomenna: overview of the village completely rebuilt (photos by [35,36]).

**Figure 30.** Santomenna: the center of the village completely rebuilt (photos by [35,36]).

**Figure 31.** Santomenna: a detail of the new buildings (photos by [35,36]).

**Figure 32.** Santomenna: the new Town Hall in reinforced concrete (photos by [35,36]).

**Figure 33.** Santomenna: S. Maria delle Grazie church (photos by [35,36]).

**Figure 34.** Sant'Angelo dei Lombardi: original map of the seismic microzonation according to [29].

**Figure 35.** Sant'Angelo dei Lombardi: the historical center with the Town Hall, reconstructed taking into account the original urban design (photos by [35,36]).

**Figure 36.** Sant'Angelo dei Lombardi: the remains of the Goleto Abbey (photos by [35,36]).

**Figure 37.** Sant'Angelo dei Lombardi: Archdiocese of Sant'Angelo dei Lombardi in the historical center: (photos by [35,36]).

**Figure 38.** Sant'Angelo dei Lombardi: Castle of the Imperials of Sant'Angelo dei Lombardi in the Historical center (photos by [35,36]).

**Figure 39.** Sant'Angelo dei Lombardi: overview of new buildings and the football field (photos by [35,36]).

**Figure 40.** Balvano: Panoramic view with the Castle in the foreground (photos by [35,36]).

**Figure 41.** Balvano: overview of new buildings (photos by [35,36]).

**Figure 42.** Balvano: the new buildings details of the architecture by R. Boffo and K. Eibl (photos by [35,36]).

**Figure 43.** Balvano: the new buildings details of the architecture by R. Boffo and K. Eibl (photos by [35,36]).

**Figure 44.** Caposele: the Town Hall in the historical center (photos by [35,36]).

**Figure 45.** Caposele: the historical center with the new buildings reconstructed taking into account the original urban design (photos by [35,36]).

**Figure 46.** Caposele: the historical center with the new buildings reconstructed taking into account the original urban design (photos by [35,36]).

**Figure 47.** Caposele: the historical center with artistic murals (photos by [35,36]).

**Figure 48.** Calabritto: panoramic view of the village completely rebuilt (photos by [35,36]).

**Figure 49.** Calabritto: The new Church of Santissima Trinità (photos by [35,36]).

**Figure 50.** Calabritto: "Largo 23 November 1980"—Memorial dedicated to the earthquake victims (photos by [35,36]).

**Figure 51.** Quaglietta: Panoramic view of the castle and its medieval village completely restored after the 1980 hearthquake. Currently the medieval village is a tourist attraction as "albergo diffuso" (photos by [35,36]).

**Figure 52.** Quaglietta: detail of the medieval village (photos by [35,36]).

**Figure 53.** Quaglietta: detail of the medieval village (photos by [35,36]).

**Figure 54.** Original map of the seismic microzonation of San Mango sul Calore according to [29].

**Figure 55.** San Mango sul Calore: Panoramic view of the village completely rebuilt after the 1980 earthquake (photos by [35,36]).

**Figure 56.** San Mango sul Calore: the new Church of Santa Maria degli Angeli (photos by [35,36]).

**Figure 57.** San Mango sul Calore: "villaggio italo-canadese" new homes built with the help of Canadians (photos by [35,36]).

**Figure 58.** San Mango sul Calore: "Villaggio S. Stefano". Temporary village, consisting of wooden chalets, built immediately after the 1980 earthquake (photos by [35,36]).

**Figure 59.** Original map of the seismic microzonation of San Michele di Serino according to [29].

**Figure 60.** San Michele di Serino: "Mariconda" palace facade, one of the few historical facades not destroyed by the 1980 earthquake (photos by [35,36]).

**Figure 61.** San Michele di Serino: the new municipal building (photos by [35,36]).

**Figure 62.** San Michele di Serino: new reinforced concrete buildings (photos by [35,36]).

**Figure 63.** San Michele di Serino: the new Church of San Michele Arcangelo (photos by [35,36]).

**Figure 64.** San Michele di Serino: the monument to the victims of the 1980 earthquake (photos by [35,36]).

**Figure 65.** San Michele di Serino: detail of Cotone Street in which there were phenomena liquefaction triggered by the earthquake [22], (photos by [35,36]).

**Figure 66.** Pescopagano: a panoramic view of the new village (photos by [35,36]).

**Figure 67.** Pescopagano: panoramic view of a part of village (photos by [35,36]).

**Figure 68.** Pescopagano: the new Town Hall of village (photos by [35,36]).

**Figure 69.** Pescopagano: "Porta della Sibilla" into the historical centre (photos by [35,36]).

**Figure 70.** Pescopagano: ruins of the medieval castle (photos by [35,36]).

**Figure 71.** Guardia dei Lombardi: panoramic view of the new village (photos by [35,36]).

**Figure 72.** Guardia dei Lombardi: the restored Church of Santa Maria delle Grazie (photos by [35,36]).

**Figure 73.** Guardia dei Lombardi: the restored historical centre (photos by [35,36]).

**Figure 74.** Guardia dei Lombardi: the new Town Hall of village (photos by [35,36]).

**Figure 75.** Torella dei Lombardi: the restored castle of Ruspoli di Candriano (photos by [35,36]).

**Figure 76.** Torella dei Lombardi: the new Church of S. Maria del Popolo (photos by [35,36]).

**Figure 77.** Torella dei Lombardi: stone plaque to remember the victims of the 1980 earthquake (photos by [35,36]).

**Figure 78.** Torella dei Lombardi: details of the new buildings (photos by [35,36]).

**Figure 79.** Torella dei Lombardi: details of the new buildings (photos by [35,36]).

**Figure 80.** Colliano: the new Town Hall of the village (photos by [35,36]).

**Figure 81.** Colliano: modern access structure with lift to Piazza Epifani (photos by [35,36]).

**Figure 82.** Colliano: New parking area of the Epifani Square (photos by [35,36]).

**Figure 83.** Colliano: New Epifani Square (photos by [35,36]).

**Figure 84.** Colliano: detail of the restored historical centre (Church of Santa Maria del Borgo) (photos by [35,36]).

**Figure 85.** Colliano: new residential settlement known as "Piano di zona" (photos by [35,36]).

**Figure 86.** Romagnano al Monte: panoramic view of the village, completely abandoned after 1980 earthquake, now ghost town (photos by [35,36]).

**Figure 87.** Romagnano al Monte: details of the old village completely abandoned after 1980 earthquake, (photos by [35,36]).

**Figure 88.** Romagnano al Monte: the Church of Maria SS. del Rosario in the new town, located in Ariola, 2 km from the old center (photos by [35,36]).

**Figure 89.** Romagnano al Monte: details of new buildings in the new town (photos by [35,36]).

**Figure 90.** Salvitelle: Panoramic view of the new village (photos by [35,36]).

**Figure 91.** Salvitelle: the new Town Hall of the village (photos by [35,36]).

**Figure 92.** Salvitelle: new buildings mainly in reinforced concrete (photos by [35,36]).

**Figure 93.** Salvitelle: details of new buildings (photos by [35,36]).

**Figure 94.** Salvitelle: plaque of a new street that remember the earthquake of 23 November 1980 (photos by [35,36]).

**Figure 95.** Senerchia: Overview of the remains of the old village (photos by [35,36]).

**Figure 96.** Senerchia: a small street of the old village (photos by [35,36]).

**Figure 97.** Senerchia: the new village, "Piazza 23 Novembre 1980" and monument dedicated to the earthquake victims (photos by [35,36]).

**Figure 98.** Senerchia: details of the new buildings (photos by [35,36]).

**Figure 99.** Senerchia: new school complex (photos by [35,36]).

**Figure 100.** Teora: panorama of the reconstructed village (photos by [35,36]).

**Figure 101.** Teora: the new Church of S. Nicola di Mira (photos by [35,36]).

**Figure 102.** Teora: new school complex and Town Hall (photos by [35,36]).

**Figure 103.** Teora: part of the restored historical centre (photos by [35,36]).

**Figure 104.** Teora: new reinforced concrete houses (photos by [35,36].

**Figure 105.** Bisaccia: the new village (Piano di Zona) with new Church of Sacro Cuore built by the architect A. L. Rossi, 1998 (photos by [41]).

**Figure 106.** Bisaccia: the new village (Piano di Zona) with a details of some reinforced concrete buildings realized by architect A. L. Rossi, (photos by [41]).

**Figure 107.** Bisaccia: the new village (Piano di Zona) with a detail of the new reinforced concrete homes designed by the architect A. L. Rossi, (photos by [41]).

**Figure 108.** Bisaccia: the new village (Piano di Zona) with the remains of the new social housing still to be completed (Istituto Autonomo Case Popolari-IACP). A part of them has been demolished in 2020 (photos by [41]).

**Figure 109.** Calitri: panoramic view of the village (photos by [35,36]).

**Figure 110.** Original map of the seismic microzonation of Calitri according to [29].

**Figure 111.** Calitri: historical centre, remains of some buildings that were recovered after the 1980 earthquake (photos by [35,36]).

**Figure 112.** Calitri: historical centre, remains of some buildings that were recovered after the 1980 earthquake (photos by [35,36]).

**Figure 113.** Calitri: panoramic view of new buildings (photos by [35,36]).

**Figure 114.** Calitri: panoramic view of the new constructions, the historical centre and the remains of the castle on the hill (photos by [35,36]).

**Figure 115.** Avellino: panoramic view of the town (photos by [35,36]).

**Figure 116.** Avellino: Rifugio Street after 1980 earthquake (cortesy of F. Capossela).

**Figure 117.** Avellino: Rifugio Street today completely reconstructed (photos by [35,36]).

**Figure 118.** Avellino: "Piazza del popolo" after the 1980 earthquake (courtesy of F. Capossela).

**Figure 119.** Avellino: "Piazza del Popolo" today completely reconstructed (photos by [35,36]).

#### **3. Conclusions**

The rebuilding process, in many localities, has been driven by microzonation maps drawn up as part of the Finalized Geodynamic Project (PFG) of the National Research Council (CNR), created immediately after the 1980 earthquake [29].

The seismic microzonation maps show the areas with different seismic characteristics, illustrating the morphological structure of the territory, the distribution of the building heritage existing in 1980, and in some cases, the level of damage suffered due the 1980 event and provide suggestions for reconstruction. We reported some examples of these maps: Castelnuovo di Conza (Figure 4), Conza della Campania (Figure 11), S. Angelo dei Lombardi (Figure 34), San Mango sul Calore (Figure 55), San Michele di Serino (Figure 60), Calitri (Figure 110).

However, the choices made for the reconstruction did not depend only on the geological assessment of the territory and therefore on the indications given by the microzoning maps, but also on the urban and socio-economic context. Nevertheless, there has not been a socio-economic redevelopment policy for the entire territory which, despite the settlement of some important factories, is currently suffering from unemployment and depopulation [45–49].

Our reportage is certainly not exhaustive, in fact there are still many other places that have undergone considerable transformations during the reconstruction process. The images can guide the future urban development of ancient villages after a major destructive seismic event, with a view to safeguarding the territory and cultural heritage. Even more than this, documenting the rebuilding process in a large epicentral area reveals the human legacy to the natural landscape, and our ability, or failure, to properly interpret the environmental fate of a site. Often in the post-earthquake reconstruction process of 1980, instead of taking into accounts the socio-economic, historical and geological local conditions, different case by case for each affected village, the policy of rebuilding at any cost has prevailed, even with buildings unsuitable for the context of the Apennine inland areas.

**Author Contributions:** Conceptualization, S.P. and E.S.; methodology, S.P.; software, R.N.; validation, R.N., G.A., G.G., E.S., A.M.M. and S.P.; formal analysis, S.P., E.S.; investigation, G.G., G.A.; resources, R.N.; data curation, R.N., G.G., G.A.; writing—original draft preparation, S.P., G.G., R.N., A.M.M. and G.A.; writing—review and editing, R.N., G.G., G.A., A.M.M.; visualization, A.M.M.; supervision, S.P.; project administration, E.S., S.P. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research received no external funding.

**Acknowledgments:** This manuscript is dedicated to all the inhabitants of these villages who experienced the terrible earthquake of 1980, but nevertheless have been able to recover with great dignity.

**Conflicts of Interest:** The authors declare no conflict of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish the results.

#### **References**


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