Seismic soil–structure interaction in multi‐span bridges: Application to a railway bridge     

Sandro Carbonari  Francesca Dezi  Graziano Leoni 《地震工程与结构动力学》2011,40(11):1219-1239

The effects of soil‐structure interaction on the seismic response of multi‐span bridges are investigated by means of a modelling strategy based on the domain decomposition technique. First, the analysis methodology is presented: kinematic interaction analysis is performed in the frequency domain by means of a procedure accounting for radiation damping, soil–pile and pile‐to‐pile interaction; the seismic response of the superstructure is evaluated in the time domain by means of user‐friendly finite element programs introducing suitable lumped parameter models take into account the frequency‐dependent impedances of the soil–foundation system. Second, a real multi‐span railway bridge longitudinally restrained at one abutment is analyzed. The input motion is represented by two sets of real accelerograms: one consistent with the Italian seismic code and the other constituted by five records characterized by different frequency contents. The seismic response of the compliant‐base model is compared with that obtained from a fixed‐base model. Pile stress resultants due to kinematic and inertial interactions are also evaluated. The application demonstrates the importance of performing a comprehensive analysis of the soil–foundation–structure system in the design process, in order to capture the effects of soil‐structure interaction in each structural element that may be beneficial or detrimental. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

Prediction of equilibrium Li isotope fractionation between minerals and aqueous solutions at high P and T: An efficient ab initio approach     

Piotr M. Kowalski  Sandro Jahn 《Geochimica et cosmochimica acta》2011,75(20):6112-6123

The mass-dependent equilibrium stable isotope fractionation between different materials is an important geochemical process. Here we present an efficient method to compute the isotope fractionation between complex minerals and fluids at high pressure, P, and temperature, T, representative for the Earth’s crust and mantle. The method is tested by computation of the equilibrium fractionation of lithium isotopes between aqueous fluids and various Li bearing minerals such as staurolite, spodumene and mica. We are able to correctly predict the direction of the isotope fractionation as observed in the experiments. On the quantitative level the computed fractionation factors agree within 1.0‰ with the experimental values indicating predictive power of ab initio methods. We show that with ab initio methods we are able to investigate the underlying mechanisms driving the equilibrium isotope fractionation process, such as coordination of the fractionating elements, their bond strengths to the neighboring atoms, compression of fluids and thermal expansion of solids. This gives valuable insight into the processes governing the isotope fractionation mechanisms on the atomic scale. The method is applicable to any state and does not require different treatment of crystals and fluids.  相似文献   

Linear soil–structure interaction of coupled wall–frame structures on pile foundations     

Sandro Carbonari  Francesca Dezi  Graziano Leoni 《Soil Dynamics and Earthquake Engineering》2011

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Implementing conservativeness in REDD+ is realistic and useful to address the most uncertain estimates     

Giacomo Grassi  Sandro Federici  Frédéric Achard 《Climatic change》2013,119(2):269-275

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Notes on Hori Method for Non-Canonical Systems     

Sandro da Silva Fernandes 《Celestial Mechanics and Dynamical Astronomy》2003,87(3):307-315

In this paper the new approach for the integration theory of the canonical version of Hori method recently proposed is extended to the non-canonical one. It will be shown that the non-homogeneous ordinary differential equation with an auxiliary parameter t* associated with the mth order equation of the algorithm can also be replaced by a non-homogeneous partial differential equation in the time t. Using a generalized canonical approach, the general algorithm proposed by Sessin is then revised; as well as the Lagrange variational equations for the non-canonical version of Hori method. A simplified algorithm derived from Sessin's algorithm is presented for non-linear oscillations problem.  相似文献   

A homogeneous sample of sub-damped Lyman     systems – IV. Global metallicity evolution     

Céline Péroux  Miroslava Dessauges-Zavadsky  Sandro D'Odorico  Tae-Sun Kim  Richard G. McMahon 《Monthly notices of the Royal Astronomical Society》2007,382(1):177-193

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Counts, Sizes and Colours of Faint Infrared-Selected Galaxies     

Paolo Saracco  Sandro D'Odorico  Alan Moorwood  Jean G. Cuby 《Astrophysics and Space Science》2001,276(2-4):991-998

Deep J- and K _s-band images covering a 5 × 5 arcmin area centred on the NTT Deep Field have been obtained during the Science Verification of SOFI at the NTT. These images were made available via the Web in early June, 1998. The preliminary results we have obtained by the analysis of these data are the following: (i) the counts continue to rise with no evidence of a turnover or of a flattening down to the limits of the survey (K _s = 22.5 and J = 24 mag); (ii) we find a slope d log(N)/dm≈ 0.37, in agreement with most of the faintest surveys but much steeper than the Hawaii survey; (iii) fainter than K _s ≈ 19and J ≈ 20 mag, the median J-K colour of galaxies shows a break in its reddening trend turning toward bluer colours; (iv) faint bluer galaxies also display a larger compactness index, and a smaller apparent size. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

List of papers from other journals     

Luciano Baresi  Sebastiano Colazzo  Luca Mainetti  Sandro Morasca 《Solar physics》1992,140(2):397-410

List of papers from other journals  相似文献   

List of papers from other journals     

Luciano Baresi  Sebastiano Colazzo  Luca Mainetti  Sandro Morasca 《Solar physics》1991,135(1):199-209

List of papers from other journals  相似文献   

Remote sensing techniques using Landsat ETM+ applied to the detection of iron ore deposits in Western Africa   总被引：1，自引：0，他引：1  

Andrea Ciampalini  Francesca Garfagnoli  Benedetta Antonielli  Sandro Moretti  Gaia Righini 《Arabian Journal of Geosciences》2013,6(11):4529-4546

Remote sensing methods enable the rapid and inexpensive mapping of surface geological and mineralogical features. This capability proves highly useful when working on isolated or inaccessible areas. In this study, several enhancements of Landsat Enhanced Thematic Mapper plus (i.e. band ratios, false colour composites and principal component analysis) were used and evaluated to obtain the best possible visualisation of iron deposits hosted in the Devonian sedimentary rocks of northwestern Africa. In particular, two test sites were chosen: southern Algeria (Djebilet area), where the literature mineralogical and geological data on iron mine fields were already available, and the Western Sahara (the southern flank of Tindouf Basin), which was investigated during a field campaign and was where the occurrence of an analogous sedimentary succession led us to hypothesise the possible presence of exploitable iron deposits. This work demonstrates the usefulness of multispectral imagery in the detection of iron-rich areas and establishes a full remote sensing procedure, which can be profitably applied to a wider region of Western Sahara and can provide interesting perspectives on the possibility of detecting new exploitable iron ore deposits in arid environments.  相似文献