Low-magnitude earthquakes in Rome: structural interpretation and implications for the local stress field     

Fabrizio Marra 《Geophysical Journal International》1999,138(1):231-243

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Deconstructing Italy: (Northern) Italians and their new perception of territoriality     

Fabrizio Eva 《GeoJournal》1999,48(2):101-107

The nineties will go down in Italian history as the decade of great political change. By way of emphasising this change, the media and politicians use the expressions `Prima Repubblica' and `Seconda Repubblica' (first and second republics), adopting the terminology used by the French for their `republics'. During the so-called First Republic (1948–1994), the centrist Christian Democrat Party represented the moderate political force in every government. However, the corruption trials of 1992–1993, which involved many of this party's members, led to its collapse at the ballot box. In northern Italy, a consequence of the demise of the Christian Democrats was the resounding success of the Lega Nord at the local government elections of 1993 and the general election of 1994. The Lega Nord based, and continues to base, its success on the use of ethno-nationalist slogans and catchcries. Italy has an ancient tradition – dating at least from the fall of the Roman Empire – of political and linguistic splintering. Given today's situation, this factor may have impacts at the level of the structure of the state: federalism, special statutes for regions and/or provinces, the decentralization of the state, and so on. For the first time for perhaps more than a century, in this new period of uncertain political change, Italians are increasingly viewing territory and its characteristics as politically relevant. Justifications for `national' cohesion are being rediscovered, or invented, at the local level, transforming it into political claims. Italians have begun to talk about relationships with territories and neighbouring groups from a different perspective. At present, traditional political parties and politicians are too slow and insufficiently focused in their response to the rising call for autonomy and decision-making authority at the local level. This factor has provided the time and space for isolationist and culturally self-reliant localist ideologies to propagate. It is impossible to say how long this period of transition will last and what its outcomes will be. The three main choices now facing Italians would be appear to be:(1) reclaim the nationalist sentiment of a united state (abandoned after the Fascist era);(2) provide the space (ideological and territorial) for the numerous localist nationalisms;(3) construct a real and flexible `localist' democracy for Italy as a whole.  相似文献   

Improved risk‐targeted performance‐based seismic design of reinforced concrete frame structures          下载免费PDF全文

Paolo Franchin  Francesco Petrini  Fabrizio Mollaioli 《地震工程与结构动力学》2018,47(1):49-67

This paper presents a procedure for seismic design of reinforced concrete structures, in which performance objectives are formulated in terms of maximum accepted mean annual frequency (MAF) of exceedance, for multiple limit states. The procedure is explicitly probabilistic and uses Cornell's like closed‐form equations for the MAFs. A gradient‐based constrained optimization technique is used for obtaining values of structural design variables (members' section size and reinforcement) satisfying multiple objectives in terms of risk levels. The method is practically feasible even for real‐sized structures thanks to the adoption of adaptive equivalent linear models where element‐by‐element stiffness reduction is performed (2 linear analyses per intensity level). General geometric and capacity design constraints are duly accounted for. The procedure is applied to a 15‐storey plane frame building, and validation is conducted against results in terms of drift profiles and MAF of exceedance, obtained by multiple‐stripe analysis with records selected to match conditional spectra. Results show that the method is suitable for performance‐based seismic design of RC structures with explicit targets in terms of desired risk levels.  相似文献   

Global Research Patterns on Ground Penetrating Radar (GPR)     

Fabrizio Terenzio Gizzi  Giovanni Leucci 《Surveys in Geophysics》2018,39(6):1039-1068

The article deals with the analysis of worldwide research patterns concerning ground penetrating radar (GPR) during 1995–2014. To do this, the Thomson Reuters’ Science Citation Index Expanded (SCI-EXPANDED) and the Social Sciences Citation Index accessed via the Web of Science Core Collection were the two bibliographic databases taken as a reference. We pay attention to the document typology and language, the publication trend and citations, the subject categories and journals, the collaborations between authors, the productivity of the authors, the most cited articles, the countries and the institutions involved, and other hot issues. Concerning the main research subfields involving GPR use, there were five, physical–mathematical, sedimentological–stratigraphical, civil engineering/engineering geology/cultural heritage, hydrological (HD), and glaciological (GL), subfields.  相似文献   

Evaluation of liquefaction potential in an intermountain Quaternary lacustrine basin (Fucino basin,central Italy)     

Paolo Boncio  Sara Amoroso  Giovanna Vessia  Marco Francescone  Mauro Nardone  Paola Monaco  Daniela Famiani  Deborah Di Naccio  Alessia Mercuri  Maria Rosaria Manuel  Fabrizio Galadini  Giuliano Milana 《Bulletin of Earthquake Engineering》2018,16(1):91-111

In this study, we analyse the susceptibility to liquefaction of the Pozzone site, which is located on the northern side of the Fucino lacustrine basin in central Italy. In 1915, this region was struck by a M 7.0 earthquake, which produced widespread coseismic surface effects that were interpreted to be liquefaction-related. However, the interpretation of these phenomena at the Pozzone site is not straightforward. Furthermore, the site is characterized by an abundance of fine-grained sediments, which are not typically found in liquefiable soils. Therefore, in this study, we perform a number of detailed stratigraphic and geotechnical investigations (including continuous-coring borehole, CPTu, SDMT, SPT, and geotechnical laboratory tests) to better interpret these 1915 phenomena and to evaluate the liquefaction potential of a lacustrine environment dominated by fine-grained sedimentation. The upper 18.5 m of the stratigraphic succession comprises fine-grained sediments, including four strata of coarser sediments formed by interbedded layers of sand, silty sand and sandy silt. These strata, which are interpreted to represent the frontal lobes of an alluvial fan system within a lacustrine succession, are highly susceptible to liquefaction. We also find evidence of paleo-liquefaction, dated between 12.1–10.8 and 9.43–9.13 kyrs ago, occurring at depths of 2.1–2.3 m. These data, along with the aforementioned geotechnical analyses, indicate that this site would indeed be liquefiable in a 1915-like earthquake. Although we found a broad agreement among CPTu, DMT and shear wave velocity “simplified procedures” in detecting the liquefaction potential of the Pozzone soil, our results suggest that the use and comparison of different in situ techniques are highly recommended for reliable estimates of the cyclic liquefaction resistance in lacustrine sites characterized by high content of fine-grained soils. In geologic environments similar to the one analysed in this work, where it is difficult to detect liquefiable layers, one can identify sites that are susceptible to liquefaction only by using detailed stratigraphic reconstructions, in situ characterization, and laboratory analyses. This has implications for basic (Level 1) seismic microzonation mapping, which typically relies on the use of empirical evaluations based on geologic maps and pre-existing sub-surface data (i.e., age and type of deposits, prevailing grain size, with particular attention paid to clean sands, and depth of the water table).  相似文献   

Seismic response prediction of reinforced concrete buildings through nonlinear combinations of intensity measures     

Alessandra Fiore  Fabrizio Mollaioli  Giuseppe Quaranta  Giuseppe C. Marano 《Bulletin of Earthquake Engineering》2018,16(12):6047-6076

A widespread approach for the prediction of the structural response as function of the ground motion intensity is based on the Cloud Analysis: once a set of points representing the engineering demand parameter (EDP) values is obtained as function of the selected seismic intensity measure (IM) for a collection of unscaled earthquake records, a regression analysis is performed by assuming a specific functional form to correlate these variables. Within this framework, many studies have been devoted so far to evaluate the effectiveness of several IMs in estimating the EDPs through intrinsically linear functional forms, but it is still unknown to what extent the use of the linear regression analysis affects the quality of the final results. This paper is intended to provide an answer to such question by means of the calibration of suitable nonlinear combinations of scalar IMs, whose statistical performances are compared with those obtained by using the functional form usually adopted for linear regression-based calibrations. Specifically, the Evolutionary Polynomial Regression technique is adopted to calibrate nonlinear regression models for the prediction of maximum inter-story drift ratio and maximum floor acceleration. The comparative analysis is performed for fixed-base and base-isolated reinforced concrete buildings subjected to ordinary or pulse-like ground motion taking into account accuracy, complexity, efficiency and sufficiency. Final results demonstrate that the linear regression analysis is suitable for fixed-base reinforced concrete buildings, but nonlinear regression models provide better estimates. On the other hand, the linear regression analysis can introduce a significant bias in the seismic response prediction of base-isolated buildings, and nonlinear regression models are deemed more appropriate.  相似文献