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On the seismic protection of free-standing art objects by base isolation technique: A case study
Published in Renato Lancellotta, Carlo Viggiani, Alessandro Flora, Filomena de Silva, Lucia Mele, Geotechnical Engineering for the Preservation of Monuments and Historic Sites III, 2022
Davide Pellecchia, Nicolò Vaiana, Salvatore Sessa, Luciano Rosati
Numerical assessments have been carried out on the Emperor Caracalla's bust, both with and without isolation. The results have shown that a base isolation having three helical wire ropes in Shear and Roll directions prevents overturning and provides small rocking angle and displacement. Finally, a one-dimensional analysis of the local seismic response, regarding seven ground accelerations compatible with the design spectra defined by the Italian Building Code, has been carried out. The results showed that the proposed isolation system can work satisfactorily even if the magnitude and the frequency content of the ground acceleration change due to seismic site effects.
Spatial distribution of soil shear-wave velocity and the fundamental period of vibration – a case study of the Saguenay region, Canada
Published in Georisk: Assessment and Management of Risk for Engineered Systems and Geohazards, 2018
Thomas Foulon, Ali Saeidi, Romain Chesnaux, Miroslav Nastev, Alain Rouleau
Local geological conditions have a major control on the intensity and frequency content of ground-shaking and on the spatial distribution of damage during strong earthquakes (Bard et al. 1988). Surficial soil deposits, having lower shear-wave velocities than bedrock, often tend to amplify and extend the duration of earthquake-related motion. This occurs as seismic waves, which carry a specific amount of energy, slow down upon encountering a low-velocity soil medium. To compensate for the reduced propagation of velocity (while conserving the amount of energy), the amplitude of the seismic waves increases. The potential for soil amplification of seismic energy is commonly referred to as the seismic site effect. Recent building codes in Europe and the United States incorporate the determination of the potential of seismic site effects into their provisions (CEN 2004; ICC 2012). Seismic site effects are defined by amplification factors with respect to a soil classification system based on the average shear-wave velocity (Vs) of the top 30 m (Vs30) as introduced by Borcherdt (1994). The current National Building Code of Canada (NBCC) (IRCC 2015) adopts the same principle although includes the modifications brought by Finn and Wightman (2004).
A multi-domain IBEM for the wave scattering and diffraction of P- and SV-waves by complex local sites
Published in Waves in Random and Complex Media, 2021
Zhenning Ba, Zhiying Yu, Ying Wang
Numerous seismic observations and damage investigations have indicated that ground motions can be extremely localized due to the seismic site effects. And in the past 40 years, local topographic effects have always been a hot research topic in the fields of geophysics, seismology and earthquake engineering. Many scholars have studied the simple single model i.e. alluvial valley, hill and inclusion etc. As for the alluvial valley, excellent analytical solutions have been provided [1–5]. Regarding the numerical methods, the semi-analytical method [4], the boundary integral equation method (BIEM) [5,6], indirect boundary element method (IBEM) [7], and boundary element-finite element coupling method (BEM-FEM) [8] are used to study the wave scattering around the single valley. As for the hill, starting from the work of Boore [9] on surface motion around a triangular hill, a large number of researches have solved the subject analytically and numerically. The analytical solution started with the solution of the semi-circular hill under plane SH-waves given by Yuan and Men [10]. Then, the solutions are extended to the semi-elliptical hill [11,12]. For the numerical methods, Sanchez-Sesma et al. [13] used IBEM to address the wave scattering by a Gaussian shape hill. Chen et al. [14–16] proposed a null-field BIEM to analyze the ground motion of a semi-circular hill, a semi-elliptical hill and a circular or an elliptical-arc hill with an inclusion. Liang et al. [17] developed indirect boundary integral equation method (IBIEM) to solve the broadband scattering of plane P, SV and Rayleigh waves by a hill topography. As for the inclusion, Pao and Mow [18] analyzed the stress concentrations for the plane waves by an embedded inclusion in infinite space. Manoogian and Lee [19] addressed the wave scattering by an arbitrary shape inclusion for the incident SH-waves in half-space. Regarding the numerical methods, Dravinski [20] adopted the BIEM to analyze the dynamic response of multiple inclusions. Dravinski and Yu [21] and Sheikhhassani and Dravinski [22] further used the BIEM to study the diffraction of the SH-waves by arbitrary number of inclusions. Chen et al. [23–25] used the null-field BIEM to study the wave scattering problem of a cavity and an inclusion.