Integrated geophysical surveys at the archaeological site of Tindari (Sicily,Italy)

The results of geophysical survey carried out at the archaeological site of Tindari, located 70 km west-north-west of Messina (Sicily, Italy), are presented and discussed. The site is one of the most important archaeological sites, about 90 ha large, on the north-eastern side of Sicily and it was one of the last Greek settlements in Sicily. Keeping in mind the vastness of the site, according to the archaeologists an area, of about 1200 m² was selected, for a geophysical survey. Electrical resistivity tomography (ERT), including induced polarization (IP) measurements, and seismic refraction tomography were applied in the course of geophysical exploration in the area. The objective of this preliminary geophysical investigation was to verify the effectiveness of the technique for a spatial definition of the buried archaeological structures (mostly walls, columns, etc.) to determine their characteristics and to study the presence of collapsed columns within the zone of archaeological interest, in view of their application in the rest of the site, that, for obvious reasons, could not be entirely excavated in brief times. The geophysical data, visualized in 3D space, revealed a distribution of low-contrast shallow anomalies that indicate the presence of different types of buried structures in the surveyed area. Also, the probable accumulations of collapsed columns could be determined. These results confirm the hypothesis of a large northern extension of the archaeological site and provide useful information to design a more efficient excavation plan.     

Jet-Pacs Project: Dynamic Experimental Tests and Numerical Results Obtained for a Steel Frame Equipped with Hysteretic Damped Chevron Braces

The experimental and numerical results obtained by Research Units of the University of Basilicata and University of Calabria for a steel frame, bare or equipped with metallic yielding hysteretic dampers (HYDs), are compared. The shaking table tests were performed at the Structural Laboratory of the University of Basilicata within a wide research program, named JETPACS (“Joint Experimental Testing on Passive and semiActive Control Systems”), which involved many Research Units working for the Research Line 7 of the ReLUIS (Italian Network of University Laboratories of Earthquake Engineering) 2005–2008 project. The project was entirely founded by the Italian Department of Civil Protection. The test structure is a 1/1.5 scaled two-story, single-bay, three-dimensional steel frame. Four HYDs, two for each story, are inserted at the top of chevron braces installed within the bays of two parallel plane frames along the test direction. The HYDs, constituted of a low-carbon U-shaped steel plate, were designed with the performance objective of limiting the inter-story drifts so that the frame yielding is prevented. Two design solutions are considered, assuming the same stiffness of the chevron braces with HYDs, but different values of both ductility demand and yield strength of the HYDs. Seven recorded accelerograms matching on average the response spectrum of Eurocode 8 for a high-risk seismic region and a medium subsoil class are considered as seismic input. The experimental results are compared with the numerical ones obtained considering an elastic-linear law for the chevron braces (in tension and compression), providing that the buckling be prevented, and the Bouc-Wen model to simulate the response of HYDs.     

Force-Based Beam Finite Element (FE) for the Pushover Analysis of Masonry Buildings

A simplified approach for analyzing the nonlinear response of masonry buildings, based on the equivalent frame modeling procedure and on the nonlinear equivalent static analyses, is presented. A nonlinear beam finite element (FE) is formulated in the framework of a force-based approach, where the stress fields are expanded along the beam local axis, and introduced in a global displacement-based FE code. In order to model the nonlinear constitutive response of the masonry material, the lumped hinge approach is adopted and both flexural and shear plastic hinges are located at the two end nodes of the beam. A classical elastic-plastic constitutive relationship describes the nonlinear response of the hinges, the evolution of the plastic variables being governed by the Kuhn-Tucker and consistency conditions. An efficient element state determination procedure is implemented, which condenses the local deformation residual into the global residual vector, thus avoiding the need to perform the inner loops for computing the element nonlinear response. The comparison with some relevant experimental and real full-scale masonry walls is presented, obtaining a very good agreement with the available results, both in terms of global pushover curves and damage distributions.     

Simulation Of Shake Table Tests on Out-of-Plane Masonry Buildings. Part (II): Combined Finite-Discrete Elements

ABSTRACT

Out-of-plane response of unreinforced masonry elements is frequently the most critical aspect of the seismic performance of existing masonry buildings. The response of such elements is usually governed by equilibrium rather than strength. Hence, it is customary to resort to rigid-body models, accounting for possible rotations, and/or sliding. However, the results of such analyses depend on the initial choice of the mechanism. In this article, the shaking-table experiments on a brick-masonry specimen, and on a stone-masonry specimen have been modeled by resorting to a combined finite-discrete element strategy. Despite the coarse discretization of both discrete and finite elements, the three-dimensional models are able to capture the experimentally observed multi-degree-of-freedom mechanisms, without any a priori assumption on the mechanism. A sensitivity analysis is carried out, addressing eight different parameters. The identification of the mechanism is sufficiently robust, but the assessment of its activation and failure is best done by combining the finite-discrete element model with a simplified model of the recognised mechanism.     

New compositional data on ancient mortars from Hagia Sophia (Istanbul,Turkey)

This study shows the results of a multidisciplinary collaboration between the University of Calabria (Italy) and the National Autonomous University of Mexico (UNAM), about the compositional characterization of some mortars taken from Hagia Sophia in Istanbul (Turkey), one of the most important buildings in antiquity. Twenty samples of joint mortars were analysed by micro-chemical analyses (SEM-EDS), X-ray powder diffraction (XRPD), optical microscopy (OM) and transmission electron microscopy (TEM). The compositional study allowed us to define, with more detail, the construction phases of the fifth, sixth and tenth century. The petrographic analysis in thin section by optical microscopy showed four typologies of sands, used as aggregate, with specific compositional features. SEM-EDS analyses and TEM observations of the binder around the ceramic fragments of the aggregate showed the presence of different morphologies of single C-S-H compounds.     

Identification of animal skin of historical parchments by polymerase chain reaction (PCR)-based methods

This study deals with establishing of a PCR-based strategy with the aim to recognize the animal origin of different historical parchments. This is one of relatively rare studies on the analysis of ancient DNA from parchments. Robustness of the PCR technology is demonstrated by successful identification of the animal species using only a small amount of DNA isolated from 12 parchment samples. Ten PCR-based assays specific for the detection of different animal species (Bos taurus, Ovis aries, Capra hircus, Sus scrofa, Oryctolagus domestica, Cervus elaphus, Capreolus capreolus, Dama dama) and two PCR assays utilizing universal primers were evaluated and optimized with the aim to find a rapid parchment identification method, which would be more reliable than the classical microscopic examination. The optimized PCR methods produced satisfactory results. Out of 12 investigated parchments, 9 items were unambiguously identified, DNA from 2 samples could not be amplified with any of the species-specific PCR assays, and only one parchment produced controversial results. The species-specific PCR results were confirmed by direct sequencing and PCR cloning with consequent sequencing. Our approach, including isolation of parchment DNA by chaotropic solid-phase extraction, optimization of the PCR programs and high-stringency annealing temperatures, demonstrated to be effective, easy and reliable for the analysis of historical parchment DNA. We consider this PCR-based strategy potentially useful also for investigation of other types of animal items conserved in museums, galleries or libraries.     

Stable isotope analysis of Late Upper Palaeolithic human and faunal remains from Grotta del Romito (Cosenza), Italy

Stable isotope analysis of carbon (δ¹³C), nitrogen (δ¹⁵N) and sulphur (δ³⁴S) were carried out on one of the largest assemblages of Late Upper Palaeolithic human remains in Southern Europe, at Grotta del Romito (Cosenza), Italy. The burials were stratigraphically dated from ca. 18,000 to 13,000 cal BP, which was confirmed by a series of new AMS dates made directly on the bone collagen. Dietary reconstruction from carbon and nitrogen stable isotopes revealed that eight of the nine individuals analysed, dating to the Final Epigravettian, had very consistent diets, rich in terrestrial animal protein, regardless of their age or sex. These included two individuals who were suffering from severe pathologies. A single individual, dating to the Evolved Epigravettian had a more variable diet, which was significantly enriched in protein from marine or freshwater fish compared to the later burials. Overall, the results are consistent with the very limited number of other studies which describe a change to more specialised and less variable subsistence strategies, in this case the hunting of large herbivores, towards the end of the Palaeolithic period. Sulphur isotope values of all of the nine burials and several faunal samples were notably consistent, showing no evidence of long-distance migration to the site from a different geological zone.     

Seismic Risk Assessment of New Zealand Unreinforced Masonry Churches using Statistical Procedures

ABSTRACT

The 2010–2011 Canterbury earthquake sequence provided extensive evidence of the significant seismic vulnerability of New Zealand unreinforced masonry (URM) churches. Given the high seismicity of the country, the exposure of human lives and the societal significance of ecclesiastic buildings, for both historical and religious reasons, the reduction in seismic vulnerability of this building type is of primary importance. By analyzing the seismic performance of a sample of 80 affected buildings, regression models correlating mean damage levels against ground-motion parameters were developed for observed collapse mechanisms, accounting for vulnerability modifiers whose influence was estimated via statistical procedures. Considering the homogeneity of New Zealand URM churches, the vulnerability models developed for the Canterbury region were extended to the whole country inventory, and a synthetic index was proposed to summarise damage related to several mechanisms. Territorial scale assessment of the seismic vulnerability of churches can assist emergency management efforts and facilitate the identification of priorities for more in-depth analysis of individual buildings. After proper calibration, the proposed approach can be applied to other countries with similar building heritage.     

Dynamic One-Sided Out-Of-Plane Behavior of Unreinforced-Masonry Wall Restrained by Elasto-Plastic Tie-Rods

Past earthquakes have shown the high vulnerability of existing masonry buildings, particularly to out-of-plane local collapse mechanisms. Such mechanisms can be prevented if façades are restrained by tie rods improving the connections to perpendiculars walls. Whereas in the past only static models have been proposed, herein the nonlinear equation of motion of a monolithic wall restrained by a tie rod is presented. The façade, resting on a foundation and adjacent to transverse walls, rotates only around one base pivot and has one degree of freedom. Its thickness is explicitly accounted for and the tie rod is modeled as a linear elastic—perfectly plastic spring, with limited displacement capacity. The model is used to investigate the response to variations of wall geometry (height/thickness ratio, thickness), tie rod features (vertical position, length, prestress level), and material characteristics (elastic modulus, ultimate elongation, yield strength) typical of historical iron. The most relevant parameter is the steel strength, whereas other characteristics play minor roles allowing to recommend reduced values for pre-tensioning forces. The force-based procedure customary in Italy for tie design is reasonably safe and involves protection also against collapse, although probably not enough as desirable.     

Planning Time: An Emergent European Practice

In the 1960s, a reduction in the time spent at work promised an increase in leisure time. Architects and planners thought that the effects of this could lead to a new form of city. Nowadays, new changes in production, technology and gender relationships de-synchronize the time regime and have fundamentally changed life in cities. Tourism and globalization exchange across the world different cultures of time. In France, the UK, and other European countries time policy is dealing with the problems arising from these changes. This article presents a short overview of time planning in Italy in two main domains: time for care, and city time. It focuses on issues such as the social demand for new shops's and services' opening hours, or how the life cycles of individuals and populations are accommodated in urban spaces. Other problems, usually not thought of in terms of time concerns, such as rehabilitation of blighted areas, historic preservation and traffic flow control, may also be treated through a time approach. Two models of planning process are presented at the end of the paper.