Site-city interaction: Theoretical, numerical and experimental crossed-analysis

L Schwan, C Boutin, L. A. Padrón, Matt Dietz, Pierre Yves Bard, Colin Taylor

Research output: Contribution to journalArticle (Academic Journal)peer-review

23 Citations (Scopus)
474 Downloads (Pure)

Abstract

The collective excitation of city structures by a seismic wavefield and the subsequent multiple Structure-Soil-Structure Interactions (SSSIs) between the buildings are usually disregarded in conventional seismology and earthquake engineering practice. The objective here is to qualify and quantify these complex multiple SSSIs through the design of an elementary study case, which serves as a benchmark for theoretical, numerical and experimental crossed-analysis. The experimental specimen consists of an idealized site-city setup with up to 37 anisotropic resonant structures arranged at the top surface of an elastic layer and in co-resonance with it. The experimental data from shaking table measurements is compared with the theoretical and numerical results provided respectively by an equivalent city-impedance model derived analytically from homogenization in the long-wavelength approximation and a model based on boundary elements. The signatures of the site-city interactions are identified in the frequency, time and space domain, and in particular consist of a frequency-dependent free/rigid switch in the surface condition at the city resonance, beatings in the records and the depolarization of the wavefield. A parametric study on the city density shows that multiple SSSIs among the city structures (five are sufficient) can have significant effects on both the seismic response of its implantation site and that of the buildings. Key parameters are provided to assess site-city interactions in the low seismic frequency range: They involve the mass and rigidity of the city compared to those of the soil and the damping of the building.
Original languageEnglish
Pages (from-to)1006-1031
Number of pages26
JournalGeophysical Journal International
Volume205
Issue number2
Early online date24 Feb 2016
DOIs
Publication statusPublished - 1 May 2016

Keywords

  • Earthquake dynamics
  • Earthquake ground motions
  • Body waves
  • Seismic anisotropy
  • Site effects
  • Wave propagation

Fingerprint

Dive into the research topics of 'Site-city interaction: Theoretical, numerical and experimental crossed-analysis'. Together they form a unique fingerprint.

Cite this