THE LETTER KILLS: ON SOME IMPLICATIONS OF 2 CORINTHIANS 3:62

The paper focuses on an argument put forward by Augustine in his De doctrina Christiana: there are passages in the Bible that need to be read in a literal, contextual, and ultimately rhetorical perspective. This approach to the Bible (usually overshadowed by Augustine's own parallel emphasis on the importance of allegory) was needed to deal with customs—for instance the patriarchs' polygamy—that had to be evaluated, Augustine argued, according to standards different from those prevailing in the present day. This need inspired Augustine to utter some sharp remarks on the need to avoid (as we would say today) ethnocentric, anachronistic projections into the Biblical text. The long‐term impact of Augustine's argument was profound. The emphasis on the letter played a significant role in the exchanges between Christian and Jewish medieval readings of the Bible, which affected Nicholas of Lyra's influential commentary (Postilla). The same tradition may have contributed to Valla's and Karlstadt's audacious hermeneutic remarks on the Biblical canon, which covertly or openly focused on contradictions in the Biblical text, questioning the role of Moses as author of Deuteronomy. Traces of those discussions can be detected in Spinoza's Tractatus theologico‐politicus. The paper suggests that the emphasis on a literal, contextual reading of the Bible provided a model for secular reading in general. The possible role of this model in the aggressive encounter between Europe and alien cultures is a matter of speculation.     

DAMAGE AND DUCTILITY DEMAND SPECTRA ASSESSMENT OF HYSTERETIC DEGRADING SYSTEMS SUBJECT TO STOCHASTIC SEISMIC LOADS

Damage phenomena observed in structures subject to intense seismic events are the result of stiffness and strength degradation. This paper studies the damage assessment of hysteretic degrading structures described by means of the Bouc-Wen model, modified to represent the mechanical degradation induced by severe earthquakes. In order to consider randomness of seismic action, the analysis is performed by adopting a stochastic approach and the Park and Ang damage functional is also evaluated in stochastic way. A parametric analysis is carried out with the aim to analyse the effect of mechanical characteristics and measure parameters of earthquake intensity on seismic response and damage level. Damage spectra are finally obtained and they are used to develop, on the basis of the Performance Based Seismic Design, ductility demand spectra.     

THE LEAD INGOTS OF CAPO PASSERO: ROMAN GLOBAL MEDITERRANEAN TRADE

Summary.   Epigraphic and isotopic analysis of the lead ingots recovered from a shipwreck off Capo Passero (in Sicily) in mid-2006 suggests that the ingots were produced in Spain, in the Cartagena region. The shipwreck is estimated to have occurred around 38 BC, at the beginning of the Hispanic era. This provides further evidence that the Romans were trading lead throughout the Mediterranean Sea.     

OUT-OF-PLANE SEISMIC RESISTANCE OF MASONRY WALLS

Seismic vulnerability of unreinforced masonry buildings is studied by means of simplified out-of-plane collapse mechanisms that take into account connections with transversal walls. According to experimental evidence, the analysis assumes that failure is reached with a rigid body motion of a part of the facade that falls down. Two classes of mechanism are examined: the overturning of the facade due either to a vertical crack at the connection or a diagonal crack on the transversal wall, both defined resorting to a simple model of masonry fabric, viewed as a regular assembly of rigid blocks and elastic plastic joints with friction but no cohesion. The use of simplified mechanisms give rise to an explicit evaluation of the seismic resistance to changes in the geometry and in the masonry fabrics, that could be used by practising engineers. This formulation is developed for both static horizontal actions and ground velocity peak, in the belief that the latter probably gives a better approximation of seismic action, while also providing, by comparison with the results of static forces, an estimate of the behaviour factor for unreinforced masonry. Eventually, the analytical forecasts are compared with numerical results obtained by means of the distinct element method.     

REPEATABLE DYNAMIC RELEASE TESTS ON A BASE-ISOLATED BUILDING

The main activities and the relevant results of an experimental program aimed at evaluating the dynamic characteristics of a large seismically isolated building are described. The building is situated in Potenza (Italy) and is the largest of five seismically isolated blocks of the University of Basilicata. Cyclic shear tests on scaled isolators and some small amplitude free vibration tests were preliminarily carried out. The latter ones were aimed at getting a preliminary linear characterisation of the structure. Finally, many in situ release tests on the isolated structure were carried out, using a mechanical device purposely designed to statically move the building and then suddenly release it, thus making it vibrate freely. The variations of the dynamic characteristics of the system while the oscillation amplitude decreases have been evaluated by using the “Short Time Fourier Transform (STFT)”. The results were elaborated in terms of stiffness and equivalent damping and compared to the results of the laboratory tests on scaled isolators, finding an excellent agreement.     

EXPERIMENTAL BEHAVIOUR OF R/C FRAMES RETROFITTED WITH DISSIPATING AND RE-CENTRING BRACES

An extensive program of shaking table tests on 1/4-scale three-dimensional R/C frames was jointly carried out by the Department of Structure, Soil Mechanics and Engineering Geology (DiSGG) of the University of Basilicata, Italy, and the National Laboratory of Civil Engineering (LNEC), Portugal. It was aimed at evaluating the effectiveness of passive control bracing systems for the seismic retrofit of R/C frames designed for gravity loads only. Two different types of braces were considered, one based on the hysteretic behaviour of steel elements, the other on the superelastic properties of Shape Memory Alloys (SMA). Different protection strategies were pursued, in order to fully exploit the high energy dissipation capacity of steel-based devices, on one hand, and the supple-mental re-centring capacity of SMA-based devices, on the other hand. The experimental results confirmed the great potentials of both strategies and of the associated devices in limiting structural damage. The retrofitted model was subjected to table accelerations as high as three times the acceleration leading the unprotected model to collapse, with no significant damage to structural elements. Moreover, the re-centring capability of the SMA-based bracing system was able to recover the undeformed shape of the frame, when it was in a near-collapse condition. In this paper the experimental behaviour of the non protected and of the protected structural models are described and compared.     

DUCTILITY AND LOAD CARRYING CAPACITY PREDICTION OF STEEL BEAM-TO-COLUMN CONNECTIONS UNDER CYCLIC REVERSAL LOADING

Abstract

The economy and reliability of steel-framed buildings in seismic areas depend basically on the hysteretic behaviour of its individual components, such as members and joints. With reference to the latter, despite the recent semi-continuous frame approach (which appears generally very convenient for the design of low- and medium-rise steel buildings), the present state of knowledge does not allow for a complete understanding of the behaviour and the low-cycle fatigue life of beam-to-column connections under dynamic loads.

This paper presents a criterion for the definition of the low-cycle fatigue strength of steel connections, and proposes two approaches for the design of steel frames in seismic zones via the assessment of the fatigue damage, which is evaluated alternatively on the basis of either the ductility or of the load carrying capacity.