Towards specific T–H relationships: FRIBAS database for better characterization of RC and URM buildings

FRIBAS database is an open access database composed of the characteristics of 312 buildings (71 masonry, 237 reinforced concrete and 4 mixed types). It collects and harmonizes data from different surveys performed on buildings in the Basilicata and Friuli Venezia Giulia regions (Southern and Northeastern Italy, respectively). Each building is defined by 37 parameters related to the building and foundation soil characteristics. The building and soil fundamental periods were experimentally estimated based on ambient noise measurements. FRIBAS gave us the opportunity to study the influence of the main characteristics of buildings and the soil-building interaction effect to their structural response. In this study, we have used the FRIBAS dataset to investigate how the building period varies as a function of construction materials and soil types. Our results motivate the need of going beyond a 'one-fits-all' numerical period-height (T-H) relationship for generic building typologies provided by seismic codes, towards specific T-H relationships that account for both soil and building typologies

Evaluation of the performance of Dutch Lipid Clinic Network score in an Italian FH population: The LIPIGEN study

Background and aims: Familial hypercholesterolemia (FH) is an inherited disorder characterized by high levels of blood cholesterol from birth and premature coronary heart disease. Thus, the identification of FH patients is crucial to prevent or delay the onset of cardiovascular events, and the availability of a tool helping with the diagnosis in the setting of general medicine is essential to improve FH patient identification.Methods: This study evaluated the performance of the Dutch Lipid Clinic Network (DLCN) score in FH patients enrolled in the LIPIGEN study, an Italian integrated network aimed at improving the identification of patients with genetic dyslipidaemias, including FH.Results: The DLCN score was applied on a sample of 1377 adults (mean age 42.9 +/- 14.2 years) with genetic diagnosis of FH, resulting in 28.5% of the sample classified as probable FH and 37.9% as classified definite FH. Among these subjects, 43.4% had at least one missing data out of 8, and about 10.0% had 4 missing data or more. When analyzed based on the type of missing data, a higher percentage of subjects with at least 1 missing data in the clinical history or physical examination was classified as possible FH (DLCN score 3-5). We also found that using real or estimated pre-treatment LDL-C levels may significantly modify the DLCN score.Conclusions: Although the DLCN score is a useful tool for physicians in the diagnosis of FH, it may be limited by the complexity to retrieve all the essential information, suggesting a crucial role of the clinical judgement in the identification of FH subjects

Soil-building resonance effect in the urban area of Villa d’Agri town (southern Italy).

This study aims to evaluate the possible increase of seismic effects due to the interaction between near surface eology and buildings in the urban area of the Villa d’Agri town (Basilicata, south Italy). 190 single-station seismic ambient noise measurements were performed, 105 on urban soils and 85 on the overlaying buildings. These measurements, analysed based on the Horizontal-to-Vertical Spectral Ratio technique, together with the detailed geological map allowed to reconstruct isofrequency and isoamplitude maps for the whole urban area as well as the relationship between the first vibrational period T(s) and the corresponding height (H) of the measured buildings. Finally, the frequencies of all buildings (659) estimated on the basis of their height have been compared to the frequency of the underlying soil thus enabling us to assess where the soil-building double resonance effect could more likely occur in case of future shaking

Soil-building resonance effect in the urban area of Villa d’Agri (Southern Italy)

This study aims to evaluate the possible occurrence during seismic shaking of interaction effects between the shallow subsoil and the overlying buildings of the Villa d’Agri town (Southern Italy). From the geological and building heritage points of view, the investigated area represents a typical town along the Apennines chain and therefore the obtained results could be easily exported to similar urban areas. A total of 239 single-station seismic ambient noise measurements were thus performed, 154 on the urban soils and 85 within buildings. Both subsets of measurements were planned to cover the main outcropping lithologies and building typologies. By means of the Horizontal-to-Vertical Noise Spectral Ratio technique, isofrequency and isoamplitude maps have been reconstructed for the whole area. The results evaluated on the 65 tested buildings allowed to infer the empirical relationship between the first vibrational period, T(s), and their height, H(m). Using this relationship and available information on the height of each building, the first vibrational frequency was estimated for 659 buildings belonging to the urban area of Villa d’Agri. Finally, in order to assess the possible occurrence of the double resonance phenomenon, we compared the main frequency of each building with that interpolated for the underlying foundation soil. The results show that the probability of being affected by the double resonance effect is very high only for a couple of buildings, high for about 16% of the buildings, moderate for the 23% and practically null for most buildings (60%)

Sharing soil and building geophysical data for seismic characterization of cities using CLARA Webgis. A case study of Matera (southern Italy)

In the context of seismic risk, studying the characteristics of urban soils and of the built environment means adopting a holistic vision of the city, taking a step forward compared to the current microzonation approach. Based on this principle, CLARA WebGIS aims to collect, organize, and disseminate the available information on soils and buildings in the urban area of Matera. The geodatabase is populated with (i) 488 downloadable geological, geotechnical, and geophysical surveys; (ii) geological, geomorphological, and seismic homogeneous microzone maps; and (iii) a new Digital Surface Model. The CLARA WebGIS is the first publicly available database that reports for the whole urban area the spatial distribution of the fundamental frequencies for soils and the overlying 4043 buildings, along with probability levels of soil‐building resonance. The WebGIS is aimed at a broad range of end users (local government, engineers, geologists, etc.) as a support to the implementation of seismic risk mitigation strategies in terms of urban planning, seismic retrofitting, and management of post‐earthquake crises. We recommend that the database be managed by local administrators, who would also have the task of deciding on future developments and continuous updating as new data becomes available