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si da conto nell'articolo di oltre dieci anni di studi, progetti accademici, workshop e sperimentazioni sul sito di alcuni comuni dell'aree interne centro meridionali del Molise, attualmente nelle aree di sperimentazione Snai, e delle considerazioni desunte da tali esperienze sul campo

Ritenere i paesaggi che oggi osserviamo delle entità consolidate e definitivamente compiute nella forma attuale, sarebbe un errore madornale oltre che un’incongruenza logica, sarebbe come pensare che la storia termini nell’attualità. Risulta facile, e forse scontato, riferirsi in tal senso al Panta rei di Eraclito, per comprendere ancora meglio, se ce ne fosse bisogno, come sia ingannevole considerare il paesaggio stabile e immutabile; il filosofo afferma che “nessun uomo entra mai due volte nello stesso fiume, perché il fiume non è mai lo stesso, ed egli non è lo stesso uomo”, allora è del tutto ingannevole considerare il paesaggio come un quadro da ammirare e fissare una volta per tutte nella memoria. In base a tali presupposti si può allora affermare che le azioni da porre in essere per salvaguardare il patrimonio paesaggistico ereditato dai nostri antenati devono necessariamente assecondare il cambiamento, che non può essere fermato ma solo ragionevolmente governato.

This paper deals with the influence of the rolling shear deformation on the flexural behavior of CLT (Cross-Laminated Timber) panels. The morphological configuration of the panels, which consist of orthogonal overlapped layers of boards, led to a particular shear behavior when subjected to out-of-plane loadings: the low value of the shear modulus in orthogonal to grain direction (i.e., rolling shear modulus) gives rise to significant shear deformations in the transverse layers of boards, whose grains direction is perpendicular with respect to the tangential stresses direction. This produces increases of deflections and vibrations under service loads, creating discomfort for the users. Different analytical methods accounting for this phenomenon have been already developed and presented in literature. Comparative analyses among the results provided by some of these methods have been carried out in the present paper and the influence of the rolling shear deformations, with reference to different span-to-depth (L/H) ratios investigated. Moreover, the analytical results have also been compared with those obtained by more accurate 2D finite element models. The results show that, at the service limit states, the influence of the rolling shear can be significant when the aspect ratios became less than L/H = 30, and the phenomenon must be accurately considered in both deflection and stress analysis of CLT floors. Contrariwise, in the case of higher aspect ratios (slender panels), the deflections and stresses can be evaluated neglecting the rolling shear influence, assuming the layers of boards as fully-connected.

The interest of the scientific community for the seismic behaviour of existing masonry buildings has largely increased in recent years, due to the fact that the seismic events have evidenced a great need of rehabilitation. Masonry structures, and especially low rise buildings, are in fact the most diffused all over the world and in particular in seismic areas in developing countries because of their ease in construction and economy. Moreover unreinforced masonry is the most diffused construction material in the major part of historical centrers in Europe. In a well engineered and constructed masonry building subjected to earthquake forces, in which out of plane mechanisms can be avoided, the contribution of in-plane shear resistance of the masonry walls is a determinant factor for the stability of the whole structure. Based on this last consideration, this paper presents an approach for the analysis of masonry walls loaded with in-plane forces, involving a minimum energy procedure. The results of the numerical analyses presented are compared with those obtained by laboratory tests on brick masonry panels.

In this paper the results of a wide experimental campaign on the structural behaviour of ancient chestnut beams are presented. The beams were taken from the floor slab of an existing building, they being representative of the bearing structures of common historical buildings of many Mediterranean countries. Therefore, they were characterized by natural defects and degradation phenomena, which may have a significant effect on the evaluation of the load bearing capacity of the member. Four beams in actual dimension have been considered, which have been subjected to static bending tests, aimed at the evaluation of stiffness, strength, post-elastic behaviour and collapse mechanism. In the paper, the global influence of relevant defect patterns on the behaviour of these beams has been evaluated by comparing their overall behaviour with the actual material response obtained by compression, bending and shear tests on defect-free small specimens. The obtained results show that the simplified methods commonly used to evaluate the bearing capacity of wooden beams can be safely applied to ancient structural members as well, provided that adequate reduction factors for the shear resistance are considered.

The refurbishment of ancient timber structures requires an acquaintance of the residual structural capacity of members in order to design reliable repairing interventions. Such information cannot be obtained by means of destructive tests on sacrificial elements extracted from the existing structures, while non-destructive tests (NDT) are currently performed in situ on timber elements. In this article, a methodology based on resistographic NDTs is analysed. In particular, an experimental campaign of NDTs on ancient chestnut elements has been carried out for determining a correlation between NDT results and mechanical wood properties, previously obtained by means of destructive tests. Then, a numerical formulation between resistographic tests carried out along the direction parallel to the grain and the longitudinal ultimate compressive stress has been proposed. In addition, since in situ NDTs can be performed only along direction transversal to the growth rings, a correlation between longitudinal and transversal NDTs has been obtained. Finally, in order to validate the proposed procedures, a series of analogous tests have been carried out also on new spruce elements.

European Timber Buildings as an Expression of Technological and Technical Cultures, ELSEVIER, 2002