demolition waste management after recent italian ...

DEMOLITION WASTE MANAGEMENT AFTER RECENT ITALIAN EARTHQUAKES F. FALESCHINI*, M.A. ZANINI*, L. HOFER* AND C. PELLEGRINO* * ICEA, Department of Civil, Environmental and Architectural Engineering, University of Padua - Via Marzolo 9, 35131, Italy

SUMMARY: This work compares the disaster waste management policies carried out in Italy, after two recent earthquakes (Mw 6.3 L’Aquila; Mw 5.86 Emilia-Romagna) and the Mw 6.46 1976 Friuli earthquake. Special attention is paid on the positive experience of building waste management in the town of Venzone, Friuli-Venezia Giulia (north-eastern Italy), which historic buildings were almost completely damaged. Indeed, it is possible to recognize that, more than 40 years after that event, the recycling program conducted by the Municipality allowed to fully recover the cultural heritage; additionally, this choice avoided significant environmental impacts, considering the alternative forms of disaster waste disposal.

1. INTRODUCTION Management of construction and demolition waste (C&DW) is one of the main challenges of the society, being the amount of those materials one of the main waste stream currently produced in the world. As an indication, in Europe C&DW account for about 30% in mass of all the waste (JRC-IES 2011). Their composition is heterogeneous, depending on many variables, such as their origin, the type of C&DW treatment plant (fixed or mobile), and the production site (Pellegrino and Faleschini 2016). Their production is not easy to be evaluated too, even if, at local scale, predictive models can be used for a proper assessment of waste volume, both in new constructions and demolition projects (Solís-Guzmán et al. 2009). However, in non-ordinary conditions, e.g. when devastating events such as earthquakes, tsunamis or hurricanes occur, such evaluation become extraordinary complex. Indeed, after disasters occurrence, the amount of demolition-generated waste may be very high, and concentrated in short time-windows (Brown et al. 2011; Faleschini et al. 2017). The great amount of waste deriving after disasters should be properly managed, because their impact may alter substantially the economy of an entire region. The strategies that should be carried out have to consider, at least, four main criteria: environmental desirability, economic optimization, administrative diligence, and lastly social acceptability and equity. Concerning the environmental desirability, this means that the effects on public health and on the environment should be considered. For instance, debris management in the emergency phase should consider facilitating rescue actions, meeting humanitarian needs and providing services (food, shelter, clothing, public health, safety), cleanup, damage assessment, and the start of resource distribution. The economic optimization regards the cost-effectiveness and economic soundness of the management strategy; the administrative diligence concerns the administrative capacity to adequately ensure that the policies can be carried out continuously in the long term. The last criteria about the social acceptability and equity refers to how receptive and supportive the local community is with respect to the waste management plan; additionally, this means that it is Proceedings Sardinia 2017 / Sixteenth International Waste Management and Landfill Symposium/ 2 - 6 October 2017 S. Margherita di Pula, Cagliari, Italy / © 2017 by CISA Publisher, Italy

Sardinia 2017 / Sixteenth International Waste Management and Landfill Symposium / 2 - 6 October 2017

necessary also to take into account potential indirect losses due to the chosen strategy. This latter criterion is particularly important after a disaster event, because it measures also the social perception of the post-disaster phase. For instance, when dealing with cultural heritage (e.g. for masonry buildings located in historic centers), such as in most small Italian towns, which may be characterized by high cultural heritage value, waste management strategies based on full recovery of the initial built environment can be implemented. In this paper, the results of three different disaster waste management strategies applied after Italian earthquakes are analyzed. Special attention is devoted to describe the experience of a small Municipality located in Friuli-Venezia Giulia (Italy), which was hit by a Mw 6.46 earthquake in 1976. This case-study is particularly interesting because the historic center was considered, also before the event, a site of cultural interest, and hence its cultural heritage value is relevant. In that case, almost all the historic buildings were rebuilt using the anastylosis reconstruction technique, employing a large amount of the original materials. Additionally, the Municipality employed large quantity of debris in river engineering applications, hence recycling almost all the disaster waste produced in the town.

2. THE Mw 6.46 FRIULI EARTHQUAKE 2.1 Pre-disaster situation Venzone is a small Municipality located in Friuli-Venezia Giulia (north-eastern Italy), in the Tagliamento River valley, separating the Julian Alps in the east from the Carnic Prealps in the west. This area is one of the most earthquake prone in Italy (Figure 1). The historic center of the town lies within the Medieval walls; it was declared as cultural monument of national importance since 1965. Between 1965 and 1976, its cultural heritage was monitored and cataloged, providing photographical documentation, which was last updated in February 1976 (a couple of months before the first quake). The St. Andrew’s Church, originally consecrated in 1338, and further expanded into a cathedral in the following centuries, is the most important example of historic building in the center. The urban morphology of the center of the walled-town developed mainly between the 13th and 14th centuries, and did not change significantly over the course of the following centuries. In 1976, the town’s center had a population of about 700, while there were about 3000 inhabitants in the entire municipality. 2.2 The event On May 6, 1976 a Mw 6.46 earthquake hit an area of about 5700 km2 in central Friuli. The event caused 989 deaths, leaving more than 100,000 people homeless, with 43,000 buildings declared unusable (more than 70,000 inspected) and damage totaling around 4.5 billion Italian lire (at the 1976 value; corresponding to about 20 billion € in 2016 terms), across 137 municipalities affected (Carulli and Slejko, 2005). A long series of aftershocks followed, including one measuring Mw 5.12 on May 9. Then, a quiescence period was observed over the summer, with almost no events reported in August. Finally, further quakes occurred on September 11 (Mw 5.29 and 5.63) and September 15 (Mw 5.92 and 5.98), with additional deaths and damage, especially close to Venzone. Overall, the aftershocks lasted about 20 months, migrating from the border with Slovenia to central Friuli, as it possible to be observed from Figure 1. The same events affected North-Western Slovenia, causing about 12,000 buildings damaged, the evacuation of about 13,000 people, but no casualties (Pipan and Zorn, 2013).


Figure 1. Seismic sequence of the Friuli earthquake during 1976-1977 (data retrieved from INGV-CPTI11). 2.3 Post-disaster phase 2.3.1. Damage assessment The effects of the Friuli 1976 earthquake sequence were very severe, in all the region. It is worth to recall that 46 Municipalities were declared as “destroyed”, 41 “severely damaged” and 52 “damaged”. Between the most hit towns, Gemona del Friuli, Buja, Bordano, Trasaghis, Majano, Osoppo, Montenars and Venzone should be cited. Particularly, Venzone was only partially damaged after the first quake in May; but the destruction level reached 90% after the two September quakes (Figure 2). Since after the first earthquake in May 1976, damage assessment was conducted by teams of volunteer technicians, who used survey forms to assess the damage entity for each building, and to estimate the financial efforts necessary to repair the damaged structures. Particularly, according to the reports elaborated between May and September, around 140 buildings were damaged in the Municipality: between these, 15% completely collapsed, 20% suffered severe structural damage, and just few of them, located far from the historic center and realized with more recent structural techniques, did not suffer any damage (Faleschini et al. 2017).

Figure 2. Temporal sequence of building damage in via Alberton del Colle (Venzone). Images retrieved from the Museum of the Earthquake “Tiere Motus” of Venzone.


Concerning the historic monuments, St. Andrew’s Church was severely damaged. The May sequence did not cause severe damage to the structure: only the southern bell collapsed, transept walls and tympanum overturned. However, the September quakes increased significantly the damage level on this Church, which was almost completely destroyed after the 11th September: the main bell tower collapsed, as well as almost all the perimeter walls. 2.3.2. Disaster waste: quantitative estimation The estimation of the amount of debris produced after a disaster represent a challenging issue. Furcas and Balletto (2012) estimated that, in all the Friuli-Venezia Giulia region, about 188,741 m3 of demolition waste were produced. This amount was completely removed after 1 year from the main event. Considering the specific case of Venzone, it can be estimated that about 30,000 m3 were produced in the historic center, taking into account a destruction level of about 90% of the buildings. Additionally, huge amount of debris was also produced due to some earthquake-induced landslides, which were located close to the historic center of Venzone, in the hamlets of Sottomonte and Portis Vecchio. 2.3.3. Disaster waste: management strategy and reconstruction An important aspect should be highlighted when explaining the waste management strategy followed by the Municipality of Venzone at that time. Indeed, the social acceptability of the postdisaster strategy was the main criterion followed during this phase. A committee and a laboratory for restoration of architectural and cultural heritage were immediately formed after the first quake. Afterwards, disaster waste was quickly regulated, with a regional law enacted one month after the event. This law aimed to: 1) recover all of the buildings suffering slight-to-moderate structural damage; 2) preserve the region’s architectural and cultural heritage. Guidelines for waste collection were formulated in July, and in September the waste management plan was approved by both the region and municipalities. Hence, as the historic center was considered as a monument of national importance, then the principle of preservation was followed during the reconstruction of Venzone, and the anastylosis technique was employed to almost all the buildings located in the center. This technique uses large amount of the original materials, and it is devoted to reuse the original stones in the same place from where they collapsed. The uncontrolled removal of debris which occurred in the first days after the event, for allowing rescue operations, was fully recovered in 1982, and each stone was un-dumped.

Figure 3. The storage site “Rivoli Bianchi”, 2 km far from Venzone’s core town (from Bellina et al. 2006).


The debris generated after the two events was analyzed, manually and visually inspected. The undamaged stones were separated, transported to the laboratory for restoration and cataloged. They were then located in various deposit (see Figure 3), structures were re-build on land (see Figure 4), and they were re-used in the same structure from they had detached from. The parts of the structures which cannot be saved were substituted with novel materials, having the same color, texture and roughness of the original. Lastly, walls were plastered only in the buildings portion of the novel material, leaving the original stones clearly visible in the façades.

Figure 4. Re-composition “on the ground” of St. Andrew Church vaults. Images retrieved from the Museum of the Earthquake “Tiere Motus” of Venzone.

2.3.4. Disaster waste: reuse rate of the disaster waste Debris produced after the seismic sequence was almost completely used in two main applications in Venzone. First of all, debris were separated between the undamaged original stones coming from the historic buildings of the center, and the materials coming from the landslides triggered by the earthquake. The former were applied to recover and re-build the damaged buildings (mainly used on the façades and external walls). The latter were employed to realize earthen walls, necessary to protect the centers from the instable landslides in the hamlets of Portis Vecchio and Sottomonte. To estimate the ratio of re-use of demolition waste in the historic building, a visual inspection of the buildings was carried out by the authors. Particularly, one “insula” was investigated: indeed, the town center can be divided into eight “insulae”, which are building agglomerates with similar geometric area, population density and structural types. For each building of one insula, the main geometric characteristics were evaluated: façade height h, width w and wall thickness t. Then, the ratio of the recovered materials was assessed, being the recycled material unplastered and hence visible in the façade walls (Figure 5). Hence, the rate of recycling within the analyzed aggregate is about 17.5% by volume of building façades. Assuming that almost the same recycling rate is maintained in the other “insulae”, the amount of recovered original stones is estimated to be around 1150 m3 in the whole historic center.


Concerning instead the debris employed for the construction of the river engineering works, after a visual inspection, it was possible to estimate the amount of re-used material. This amount was estimated as 59,000 m3, for one wall with 640 m length in Sottomonte; another located in Portis Vecchio, having an extension of 400 m, employed about 19,000m3 of debris.

Figure 5. Assessment of the recovered amount of original stones in a building in via Alberton del Colle (Venzone).

3. THE Mw 6.3 L’AQUILA EARTHQUAKE On April 6, 2009 a Mw 6.3 event hit the Abruzzo region (central Italy); L’Aquila was the principal city located close the epicenter, and there 308 casualties were reported. A swarm, lasting since the end of 2008, occurred previously the main shock; then a long series of aftershocks followed, some of these with a magnitude greater than Mw 5.0 (D’Ayala and Dolce, 2011). After this event, various estimation of the amount of earthquake waste were carried out, with results ranging between 1 and 3 million m3. A more precise estimate is furnished by Furcas and Balletto (2012), this being about 2,650,000 m3. It is worth to note that the debris removal operations are not concluded yet, even though a Ministerial Decree was quickly enacted, in the immediate months after the event, to ensure a rapid waste management and encouraging high recycling ratio of such material. However, the recommended application of recycled aggregates potentially obtained after debris treatment was environmental filling and rehabilitation of closed quarries only. The plan selected one site for potential placement of about 935,000 m3 of recycled aggregates, and it also estimated the required time for debris removal from the affected areas, aiming to achieve a removal of around 2000 metric tonnes/day, for about 250 days. However, the theoretical expectations of such plan encountered a great limitation: when analyzing the waste management strategy, one of the criteria necessary for a satisfying waste management plan was not considered. Indeed, the administrative diligence was not properly taken into


account: Furcas and Balletto (2012) reported that earthquake waste was assimilated to municipal waste, and hence municipalities must deal with its removal, collection, transportation, recovery and disposal. However, the mayors could not proceed with the complete removal of debris because they reported a lack of technical and economic resources. Brown et al. (2010) analyzed the situation of L’Aquila after 11 months from the main event, and observed that debris management process had already started. Many temporary and permanent disposal sites had almost been approved after one year later, and a large part of the so-called “red zone” of inside the historic center was still full of debris. Table 1 shows the removal data of the demolition waste collected after the 2009 L’Aquila earthquake (expressed in tonnes). Data are available until May 2016.

Table 1. Debris removal after the 2009 L’Aquila earthquake (expressed in tonnes). YEAR

AMOUNT OF REMOVED DEBRIS

2009

33,029

2010

69,720

2011

94,939

2012

436,595

2013

641,490

2014

543,739

2015

564,381

2016

564,380

4. THE Mw 5.86 EMILIA-ROMAGNA EARTHQUAKE On May 20, 2012 a Mw 5.86 earthquake hit a densely populated area in northern Italy, between the regions Emilia-Romagna, Lombardia and Veneto. The event caused 7 deaths, about 50 people injured, and left 5000 people homeless. A series of aftershocks occurred in the following days, until a second Mw 5.66 main shock struck the same zones on May 29, causing 20 further deaths and about 350 people injured. After this second event, the number of people left homeless increased to about 15,000 (Magliulo et al. 2014). The most affected region was Emilia-Romagna, and mainly the districts of Bologna, Modena, Reggio Emilia and Ferrara. The estimated amount of debris produced in the region after the seismic sequence is about 364,400 m3, according to the annual reports of the Environmental Agency of Emilia-Romagna. The overall amount of debris produced instead in all the region affected by the seismic event was not established, due to difficulties reported by the different strategies performed by the involved Regional Authorities. In Emilia-Romagna, the waste management strategy was to assign them a CER code 20.03.99: this choice allowed a faster removal of the debris, which was performed by existing solid waste management companies. A regional regulation was approved on June 6, 2012 to establish the storage sites and the duration of the removal operations, estimated in 150 working days. However, lastly the collection took almost 2 years, as shown in Table 2. Concerning the potential re-use of such disaster waste, a regional ordinance encouraged the reuse of the debris as recycled aggregate for environmental filling and potential application in civil engineering works, e.g. in road sub-base. However, its implementation in the latter types of application was not effectively applied at large scale.


Table 2. Debris removal after the 2012 Emilia-Romagna earthquake (expressed in tonnes). YEAR

AMOUNT OF REMOVED DEBRIS

2012 2013 2014

268,648 289,707 576,943

5. CONCLUSIONS Management of disaster waste still represents a problem of great concern during postdisaster phase. Four criteria should be considered for developing a satisfying waste management strategy, being environmental desirability, economic optimization, administrative diligence, and lastly social acceptability and equity. Considering these criteria, three Italian experiences were analyzed, highlighting how administrative diligence and social acceptability are fundament for the success of such management strategies. Particularly, after the 1976 Friuli earthquake, a policy of recycling of C&DW and earthquake-induced landslides debris was implemented in the town Venzone. Huge amount of recycled material was employed in river protection works, whereas the original whole stones from the historic buildings in the town center were stored, classified, and re-used for building restoration. This operation not only allowed the preservation of Venzone cultural heritage, but also savings in terms of environmental emissions, by avoiding the use of virgin aggregates, and land consumption. Even though the initial costs to carry out such strategy could be higher than the ones for alternative strategies, the benefits during time could be observed also in terms of tourism income, which has been increasing over the last few years, and whose efforts have been rewarded by the nomination of Venzone as “Italy’s Most Beautiful Village of 2017”. Conversely, no effective recycling policies were promoted by the regions involved after the L’Aquila 2009 and Emilia-Romagna 2012 earthquakes.

AKNOWLEDGEMENTS The authors would like to thank the Museum of the Earthquake “Tiere Motus” of Venzone (UD, Italy) and Mr. Aldo Di Bernardo for their support; the Municipality of Venzone (UD, Italy) and the Major Mr. Fabio Di Bernardo.

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