Shake table tests on standard and innovative temporary partition walls          下载免费PDF全文

Crescenzo Petrone  Gennaro Magliulo  Gaetano Manfredi 《地震工程与结构动力学》2017,46(10):1599-1624

Shake table tests are performed on temporary internal partitions for office buildings. Four different specimens are tested. A steel frame is designed to exhibit relative displacements which typically occur at a given story of ordinary buildings. Four different partition walls are tested simultaneously for each specimen typology. This allows investigating the influence of an innovative device on the seismic performance of the tested components. The innovative device avoids the unhooking of the panels from the supporting studs. Several shake table tests are performed subjecting the specimens to interstory drift ratios up to 1.57%. Both the hysteretic curves and the natural frequency trend highlight that the partitions do not contribute to the lateral stiffness of the test setup. The damping ratio increases after the partition walls are installed within the test frame, causing a beneficial effect in the dynamic response. Minor damage state occurs for interstory drift ratio (IDR) in the range 0.41–0.65% in standard specimens, whereas moderate and major damage states are attained for IDR in the range 0.51–0.95%. Significant increase of collapse IDR is recorded with the introduction of the innovative device, up to IDR larger than 1.45%. It can be therefore concluded that a simple innovative device is defined, which significantly improves the seismic performance of the tested specimen. Copyright © 2017 John Wiley & Sons, Ltd.  相似文献   

Solar internal rotation and dynamo waves: A two-dimensional asymptotic solution in the convection zone     

Gaetano Belvedere  Kirill Kuzanyan  Dmitry Sokoloff 《Journal of Astrophysics and Astronomy》2000,21(3-4):379-380

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Starved versus alluvial river bedforms: an experimental investigation     

Gaetano Porcile  Paolo Blondeaux  Marco Colombini 《地球表面变化过程与地形》2020,45(5):1229-1239

Laboratory experiments were conducted to investigate the formation of river bedforms under sediment supply-limited conditions, i.e. when a motionless substratum is bared by the dynamics of the mobile sediments. Three series of experiments were organized in a laboratory flume by fixing all the hydrodynamic and morphodynamic parameters but varying the thickness of the initial layer of mobile sediments which covers the rigid bottom of the flume. At the end of all the experiments, which lasted for the same amount of time, the formation of transverse sand dunes was observed. For decreasing , the rigid bottom of the flume was bared progressively earlier during the experiment and the measurements showed a clear tendency of the bedforms to lengthen, i.e. to increase their crest-to-crest distance. Moreover, under strong supply limitation, the two-dimensional transverse dunes turned into three-dimensional barchanoid forms and into isolated barchan dunes characterized by an abrupt reduction in bedform heights. A two-dimensional Fourier analysis of the bottom profile was performed, providing the amplitude of the main streamwise and spanwise harmonic components of the bottom morphology as a function of . © 2019 John Wiley & Sons, Ltd.  相似文献   

Parametric study on seismic ground response by finite element modelling     

Angelo Amorosi  Daniela Boldini  Gaetano Elia 《Computers and Geotechnics》2010

In this paper the results of 2D FE analyses of the seismic ground response of a clayey deposit, performed adopting linear visco-elastic and visco-elasto-plastic constitutive models, are presented. The viscous and linear elastic parameters are selected according to a novel calibration strategy, leading to FE results comparable to those obtained by 1D equivalent-linear visco-elastic frequency-domain analyses. The influence of plasticity on the numerical results is also investigated, with particular reference to the relation between the hysteretic and viscous damping effects. Finally, different boundary conditions, spatial discretisation and time integration parameters are considered and their role on the FE results discussed.  相似文献   

Non-life insurance consumption in Italy: a sub-regional panel data analysis   总被引：1，自引：0，他引：1  

Giovanni Millo  Gaetano Carmeci 《Journal of Geographical Systems》2011,13(3):273-298

We analyze the consumption of non-life insurance across 103 Italian provinces in 1998–2002 in order to assess its determinants, in the light of the empirical literature. Using sub-regional data, we overcome an important limitation of cross-country analyses, i.e. the systemic heterogeneity due to country-specific characteristics. Individual heterogeneity is accounted for through panel data techniques. However, considering spatial units within a single market raises issues of cross-sectional or spatial dependence, either due to common nationwide and/or regional factors or to spatial proximity. We carefully assess spatial dependence, employing recent diagnostic tests, finding out that the regressors included in our specification successfully account for spatial dependence. Insurance turns out to depend on income, wealth and some demographics, as already established, but also on trust, judicial efficiency and borrowing conditions. These findings help in explaining the gap between Central-Northern Italy and the south of the country.  相似文献   

Numerical prediction of tunnel performance during centrifuge dynamic tests   总被引：2，自引：1，他引：1  

Angelo Amorosi  Daniela Boldini  Gaetano Falcone 《Acta Geotechnica》2014,9(4):581-596

In this paper, a comparison between numerical analyses and centrifuge test results relative to the seismic performance of a circular tunnel is provided. The considered experimental data refer to two centrifuge tests performed at Cambridge University, aimed at investigating the transverse dynamic behaviour of a relatively shallow tunnel located in a sand deposit. For the same geometry, different soil relative densities characterise the two tests. The four seismic actions considered, of the pseudo-harmonic type, are characterised by increasing intensity. The 2D numerical analyses were performed adopting an advanced soil constitutive model implemented in a commercial finite element code. The comparison between numerical simulations and measurements is presented in terms of acceleration histories and Fourier spectra as well as of profiles of maximum acceleration along free-field and near-tunnel verticals. In addition, loading histories of normal stress and bending moments acting in the tunnel lining were considered. In general, very good agreement was found with reference to the ground response analyses, while a less satisfactory comparison between observed and predicted results was obtained for the transient and permanent loadings acting in the lining, as discussed in the final part of the paper.  相似文献   

Atmospheric Background Measurement in the 300–400 nm Band with a Balloon Borne Experiment During a Nocturnal Flight     

Giovanni La Rosa  Gaetano Agnetta  Benedetto Biondo  Osvaldo Catalano  Filippo Celi  Renato Di Raffaele  Salvatore Giarrusso  Angelo Mangano  Francesco Russo  John Linsley  Angelo Lo Bue 《Astrophysics and Space Science》2001,276(1):219-226

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L’Istituto vulcanologicom l’ Osservatorio etneo e l’attività scientifica del personale     

Gaetano Ponte 《Bulletin of Volcanology》1937,2(1):201-204

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Finite element simulation of freezing processes in soils     

S. Del Giudice  G. Comini  R. W. Lewis 《国际地质力学数值与分析法杂志》1978,2(3):223-235

The finite element method, formulated for non-linear heat conduction, allows the solution of practically any ground freezing problem. Stabilization of wet soils by artificial freezing and freezing under roads induced by cold winter conditions are considered in this paper. Special features of the program used include parabolic isoparametric elements, a new time stepping scheme and an improved procedure for the estimation of thermal properties.  相似文献   

Damage‐dependent vulnerability curves for existing buildings     

Maria Polese  Marco Di Ludovico  Andrea Prota  Gaetano Manfredi 《地震工程与结构动力学》2013,42(6):853-870

Seismic behavior of damaged buildings may be expressed as a function of their REsidual Capacity (REC), which is a measure of seismic capacity, reduced by damage. REC can be interpreted as the median value of collapse vulnerability curves. Its variation owing to damage is a useful indication of increased building vulnerability. REC reduction, indicating the lowering of seismic safety after an earthquake (performance loss, PL), represents an effective index for assessing the need of seismic repair/strengthening after earthquakes. The study investigates the applicability of a pushover‐based method in the analysis of damaged structures for the case of existing under‐designed RC buildings. The paper presents a systematization of the procedure in an assessment framework that applies the capacity spectrum method based on inelastic demand spectra; furthermore, the vulnerability variation of a real building is investigated with a detailed case study. The behavior of damaged buildings is simulated with pushover analysis through suitable modification of plastic hinges (in terms of stiffness, strength and residual drift) for damaged elements. The modification of plastic hinges has been calibrated in tests on nonconforming columns. The case study analysis evidenced that, for minor or moderate damages, the original structural displacement capacity was only slightly influenced, but the ductility capacity was significantly reduced (up to 40%) because of the increased structure deformability. This implied performance loss in the range 10%–20%. For severe damages the PL ranged between 41% and 56%. Local mechanism types exhibit PL nearly double with respect to global mechanism types. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献