Nicola Ruggieri

Typical Failures, Seismic Behavior and Safety of the “Bourbon System” with Timber Framing

All the research on the behavior and failure of specimens of the Bourbon System, masonry with timber framing, has been done on early 1900 C photographic records. The photos show some case baraccate damaged by the 1905 and 1908 seismic events. The damage is recorded also in the official documents of the technicians sent from Rome, just like Commissione del Genio Civile [, including Canevazzi and Panetti. More data come from Baratta punctual description [ who visited Calabrian towns damaged in the 1908 earthquake. Other news has been taken out from some old chronicles regarding timber frame buildings before 1783.

Behaviour of the Borbone Constructive System Under Cyclic Loading: Preliminary Report

The Borbone constructive system, constituted by masonry reinforced with timber frames, was conceived in the Calabria region after the earthquake of 1783. In fact, subsequently to this catastrophic event Ferdinando of Borbone the IV immediately drew up an anti-seismic code in which prescribed, among the other rules, the buildings reconstruction to be carried out with the reinforcement of a skeleton of timber elements. Also the residence of the Bishop of Diocese of Mileto-Nicotera-Tropea was built in Mileto (Vv), at the end of 18th c., adopting the Borbone anti-seismic system. This “baracca” of the Bishop was investigated with an accurate dimensional and structural survey, supported by petrographic and chemical analysis of mortars and stones and by assessment of the wood species of the inner members of the load bearing system. All these data allowed the designers to realize an “imperfectly” identical copy of the bishop’s building wall. The paper will present the results of quasi-static cyclic tests according to UNI EN 12512:2003, on the full scale specimen of the Mileto masonry reinforced with timber framing. Furthermore, the hysteretic behaviour (ductility, energy dissipation, equivalent viscous damping ratio, strength impairment) of the Borbone constructive system will be discussed in the document, with a special focus on the single anti-seismic contribution of masonry and timber frame to the overall cyclic stiffness.

In-Plane Versus Out-of-Plane “Behavior” of an Italian Timber Framed System—The Borbone Constructive System: Historical Analysis and Experimental Evaluation

The Borbone system, elaborated after the terrible earthquake that in 1783 hit the southern part of the Calabria Region, is constituted by masonry reinforced with timber frames. It represents the synthesis of the most advanced anti-seismic criteria of the time, the Age of the Enlightenment. With the present study based on pictures and reports of the time as well as on the results of experimental trials on real scale (1:1) models, the authors intend to contribute to the interpretation of the behavior to seismic actions of the cited Borbone system and decoding the answer of the system to horizontal forces both parallel (by means of experimental analysis) and perpendicular to the walls (relied on historical data). The values collected in the cyclic tests—such as ductility, strength impairment, equivalent viscous damping, and energy dissipation, conducted on two samples: masonry wall reinforced by timber frames and timber framed wall without infill)—have been compared with the experimental data concerning other framed masonry systems (Gaiola and Dhajji Dewari) bringing out the constructive and mechanical differences as well as similarities.

Pompeii’s Stabian Baths. Mechanical behavior assessment of selected masonry structures during the 1st century seismic events

ABSTRACT The eruption of Mount Vesuvius in 79 AD buried and preserved the Stabian Baths building in the exact configuration which the archaeological excavations carried out in the second half of the 19th century recovered. By combining archeologists’ studies with the analysis of deformations and cracking pattern due to the 1st century seismic events, in this article numerical models have been formulated which allowed the formation of some hypotheses coherent on the timeline of the events, the damage to as well as the change of the shape and stylistic language of the thermal building. Specifically, through global seismic analyses and kinematic analyses of masonry portions of the “destrictarium” block, it is proven that during the 1st century not only a sole catastrophic earthquake occurred but, at least, two important seismic events took place. The purpose of this article is to identify and parameterize the responsible earthquake by the analysis of seismic effects detectable in the damages and archaeological remains of the masonry walls of the Stabian Baths. The identification of the earthquake and the grading of provoked damages represent a useful knowledge tool that provides information about the vulnerability of ancient buildings and can be suitably used also to safeguard architectural heritage from seismic risk.

A Novel Numerical Tool for Seismic Vulnerability Analysis of Ruins in Archaeological Sites

ABSTRACT Ancient masonry constructions in archaeological sites are often ruins or remains of wider portions. Therefore, archaeological artifacts generally occur as a discontinuous set of walls or columns detached from the original context. The absence of most of the original structural portions makes them much more vulnerable. Indeed, even if their current existing condition is an indicator of their equilibrium condition under gravitational loads, this condition is not sufficient to guarantee their preservation in the case of an unexpected earthquake. Furthermore, the cracking patterns and collapses make them even more vulnerable. For these reasons, the vulnerability of ruins should be addressed as regard to the possible failure mechanisms that can be activated by seismic actions. Accordingly, in this article a novel and targeted numerical tool for seismic vulnerability assessment of remains in archaeological sites, that considers collapse mechanisms occurrence as the main cause of masonry constructions being lost, is presented. Results of the numerical procedure proposed are compared with the results obtained by the canonical formulation of virtual works. Finally, the seismic vulnerability level of selected masonry constructions in the archaeological sites of Pompeii and Arpino (Italy) has been assessed by the use of this procedure.

Seismic Protection in Pompeii during the Age of Nero and Vespasian

AbstractAn earthquake of significant magnitude struck the Vesuvian area in common era (CE) 62. The earth tremors, originated by subterranean winds according to Roman seismology, provoked extensive ...

Seismic Vulnerability of the Ancient Pompeii through the Evaluation of the 62 AD Earthquake Effects

ABSTRACT The ancient Pompeii was hit by a sequence of earthquakes during the 1st century with disastrous consequences on the buildings. Many constructions were repaired after the ground shaking, others, in particular public buildings present, still today, signs of active works at the time of the Vesuvius eruption. Moreover, cracks and deformations originated from the 1st century tremors are visible on the walls and represent a precious source of information on the ultimate performance of the constructions. Despite a high in-plan geometric heterogeneity, the Pompeians’ housing stock was limited to two storeys with, often, an in-plan and along the height uniform distribution of masses, strength and stiffness, hence a reduced torsional motions tendency under earthquake actions. Furthermore, the seismic performance of the building could be influenced by the masonry arrangement and components properties, ranging, in the analysed cases, from the opus quadratum to the structura fabric, i.e. a concrete nucleus covered by stones or bricks leaf. The paper provides the key features, although of qualitative type, of the constructions vulnerability level during the last phase of the Pompeii’s history, basing on the “seismic” improvement interventions, on ancient deformations and repaired cracks, compared to the buildings configuration and the used constructive techniques.

Gaiola vs. Borbone System: A Comparison between 18th Century Anti-Seismic Case Studies

ABSTRACT This article briefly discusses the seismic-resistant heritage of the 18th century, circumscribed in Lisbon’s Baixa Pombalina (post 1755) and case baraccate of Southern Italy (post 1783). A comparison of these anti-seismic systems is discussed through the architectural principles and the mechanical behavior. It is shown that, despite the wide diversity of cases and the different geo-historical conditioning, both systems arise from an intuition of the compound seismic efficiency, the typical pragmatism of the enlightenment period and an interpretation of the classic composition code. Two specific case studies, a private building in Baixa Pombalina (Lisbon) and the Bishop’s Palace of Mileto (Calabria region) are compared. We briefly analyze: (i) configuration and structural principles; (ii) characteristics of the materials; and (iii) seismic behavior. A standardized spatial morphology closely linked to traditional construction techniques positively determines the seismic response and it is one of the key common factors in this heritage to be preserved. In both cases, the architectural and structural choices are crucial to the seismic response of the building and must be respected as an identity of a specific technical knowledge. Moreover, this materiality represents a historical continuity of the community’s memory that requires transdisciplinary, critical understanding, and preservation.

Seismic Performance Evaluation of Timber—Framed Masonry Walls Experimental Tests and Numerical Modelling

The Borbone constructive system used in Calabria at the end of the 1700s consisted of a particular composite structure realized by means of a timber frame suitably embedded inside masonry walls. This system used with similar purposes, although in different ways, in other places in the world (especially in seismic regions), can represent, with good reason, the synthesis of scientific knowledge in eighteenth century seismic engineering. The aim of the paper is to investigate and evaluate the seismic performance of the structure described above through a comparison between experimental tests, carried out by means of cyclic tests on 1:1 scale models, and the results obtained by the numerical modeling of the mechanical system that is capable of interpreting the actual contribution of the wooden structure, as well as that of the masonry, to the overall stiffness of the wall. In the numerical procedure, the masonry infill is modeled by rigid blocks connected by unilateral elastic contact constraints. A convenient way to define the contact device which links the blocks, through which a mortar joint or dry joint could be simulated, is to consider a set of elastic links, orthogonal to the contact surface between two adjacent blocks, and an additional link, parallel to the interface through which the shear forces can be transmitted. Reasonable hypotheses can be assumed for the link parallel to the contact surface in order to calibrate both the shear behaviour and the influence of the friction between the blocks. Furthermore the timber frame is modeled by using finite elements with elastic and bilateral behaviour. Unilateral contact constraints are again used in the contact interfaces between elements in wood and masonry blocks which take into account the actual contribution of friction. The mechanical parameters used in the numerical model were deduced from the experimental laboratory tests.

The Borbone “Istruzioni per Gli Ingegnieri”: A Historical Code for Earthquake-Resistant Constructions

ABSTRACT The paper examines the instructions (Istruzioni and Suggerimenti) issued by order of Ferdinando IV of Borbone, King of Naples, in 1783 soon after the terrible earthquake that hit the Calabria Ulteriore region. The tremor had disastrous consequences on the morphology of the territory and on the local economy also making 30.000 human victims. The code was drawn by the two supervisors of the public works in the Calabria region, La Vega and Winspeare. It touches several points of building policy such as hygienic precautions, city planning, measures of civil protection and administrative rules for the distribution of soils for the reconstruction of the ruined estates. The very interesting point is that the document contains updated indications for the best practice of building in a zone with high seismicity, based on the most advanced theories of the time in the field of earthquake-resistant constructions. The document suggests to keep low the height of the new buildings, forbids the construction of vaults and prescribes the construction of a timber frame to be built into the masonry walls with the aim of connecting the various walls of the building and achieve a box behaviour of the whole construction. Furthermore, indications deal with the best practice for increasing the durability of the internal timber frame.