A Resilience and Robustness Oriented Design of Base-Isolated Structures: The New Camerino University Research Center

This paper analyses the new Research Centre designed for the University of Camerino and entirely financed by the national Civil Protection Department (DPC), following the seismic events in Central Italy in 2016. The building has been designed to guarantee speed of execution as well as a high level of safety, especially regarding seismic actions. The structural solution was to create an isolated system with a steel braced super-structure with pinned joints and r.c. sub-structures able to adapt to the complex morphology of the area. As described in the first part of the paper, design choices have been made to achieve a high level of resilience and robustness, i.e., to limit damage to structural and non-structural components and equipment under moderate and design seismic actions and to avoid disproportionate consequences in the event of extreme actions, larger than the design ones. In the second part of the paper, specific risk analyses have been carried out to evaluate the real performance of the building under increasing intensity levels, with reference to both serviceability and ultimate conditions. To this purpose a site-specific hazard study was first conducted, then non-linear analyses were performed using a hazard-consistent set of records with return periods ranging from TR = 60 years to TR = 10000 years. The main demand parameters of both the isolation system and the super-structure were recorded and capacity values corresponding to different ultimate and damage limit conditions were defined. The results obtained in terms of demand hazard curves show that the building performances in terms of robustness and resilience are very high, confirming the efficacy of the strategies adopted in the design

Behaviour of structures isolated by HDNR bearings at design and service conditions

High-Damping Natural Rubber (HDNR) bearings are widely employed for seismic isolation. These bearings are characterized by a remarkable nonlinear behaviour and often by a degrading cyclic response, induced by the addition of filler to enhance its dissipation capacity. This latter phenomenon, denoted as stress-softening or Mullins effect, can significantly influence the nonlinear dynamic response of isolated structures leading to a variability of the seismic response of isolated buildings. Moreover, the behaviour of HDNR bearings may produce an amplification of response, due to higher modes contribution, which can affect the performance of non-structural components and equipment. Models providing an accurate description of the nonlinear behaviour of HDNR bearings with significant stress-softening have been proposed only recently. Thus, the studies in the literature are generally based on simplified models. In this paper, an advanced HDNR model, accounting for variation of stiffness and damping with the strain amplitude and deformation history, is used to analyse the seismic performance of isolated structures at different intensity levels. First, a parametric analysis is carried out on a two-degree of freedom system to study different configurations of practical interest. Subsequently, a multi-degree of freedom system representing a realistic building is analysed to evaluate the response at different floors and the contribution of higher modes of vibration. The influence of practical aspects, such as the superstructure damping and the friction of the sliders, is also investigated

Seismic reliability of buildings isolated with rubber bearings

The full-text of the thesis is availabl

Statistical modelling of HDNR bearing properties variability for the seismic response of isolated structures

This paper reports some results of an ongoing Research Project called RINTC aimed at computing the risk of collapse of buildings conforming to the Italian Seismic Design Code. The project involves different areas of application (reinforced concrete, masonry, steel buildings, etc.) including reinforced concrete (RC) buildings equipped with isolation systems. In particular, this paper focuses on seismic isolation systems based on High Damping Natural Rubber (HDNR) bearings, which are widely employed for buildings and other structures. The aim of the paper is to evaluate the response dispersion due to the uncertainties in the seismic input as well as the variability of the isolation system properties. The study proposes a model to define the production variability of the bearing properties, taking into account the tolerance allowed in factory production control tests (FPCT) by the European code on anti-seismic devices (EN15129). To this purpose, in the first part of the paper, experimental results of groups of HDNR bearings belonging to different batches (classes) has been analysed, focusing on the values of shear stiffness and damping coefficient at design deformation and their correlation inside and between device groups. Both the intra-class and inter-class variability affecting the HDNR isolator properties are evaluated, by using a proper statistical model. Successively, the effect on the properties variability of the FPCT acceptance criteria provided by the European code is evaluated. In the second part of the paper, results of multi-stripe analyses carried out on a base isolated prototype consisting of a 6-storey RC building are presented for increasing ground motion intensities. In particular, several varied parameters of bearings are sampled starting from mean properties and by using the statistical model calibrated from test data. The influence of the bearings parameters variability on the most interesting engineering demand parameters (EDPs) and on collapse modalities is evaluated and discussed

Innovazioni tecnologiche nella filiera olivicola-olearia per la produzione di oli funzionali di alta gamma ad elevato impatto bionutrizionale e salutistico

Some results concerning the compositional traits of destoned and organic-destoned extravirgin olive oils are referred to in this research paper. An innovative destoning-based olive processing technology has been studied. The purpose of this scientific investigation was to obtain new products with enhanced quality level and increased contents of nutraceuticals and bioactive phytomolecules. The drawn oil samples were fully characterised by using different instrumental analytical techniques. The above new oil kinds (the organic-destoned ones noticeably) stood out for their marked hedonicity, due to the optimal composition of their aroma and flavour, and for their contents of bioactives and bionutritional factors. They are thus high-added value products and therefore can contribute to enhance the competitiveness of the olive oil sector

Profiling the volatile and biophenol fractions in new oil products from olive processing

This experimental work is a focus on new virgin olive oil kinds (characterized by enhanced quality level) obtained by processing both non-organic and organic destoned olives. These latter products have excellent quality features and are also called biodestoned oil. Comparisons with reference oils have been made. In fact destoner, due to its bland action, does not induce the mechanical and thermal stress of olive paste. Moreover, the oxido reductase enzymes (peroxidases and polyphenoloxidases noticeably), plentifully present in the fruit kernel, which fix O2 to both glycerides and fatty acids, are removed. Their action also results in biophenol oxidation processes. However, the kernel oil is essentially not extracted under the operating conditions used in oil mill (1-2). Removal of the endocarp leads to obtain a solid by-product (olive pomace) in which the minute stone fragments are fully absent. So, its digestibility and nutritional value are significantly enhanced. Its relative oil content also is meaning fully increased, so that a remunerative industrial recovery of this by hexane could alternatively be carried out. The vegetation water is richer in biophenol sowing to lower presence of oxidoreductases. The olive seed oil is industrially interesting as well, thanks to their contents of oleuropein, nüzenide and squalene. The woody part of olive stone, in addition to being an excellent fuel (calorificpower=~4000kcalkg-1), can be utilized to recovery furan products. These in turn are exploitable to obtain other chemicals. Such a global industrial exploitation of the highly polluting oil mill by-products moreover solves the well-known problem concerning their strong environmental impact