@article{fdi:010070276,
  title = {{U}sing ambient vibration measurements for risk assessment at an urban scale : from numerical proof of concept to {B}eirut case study ({L}ebanon)},
  author = {{S}alameh, {C}. and {B}ard, {P}. {Y}. and {G}uillier, {B}ertrand and {H}arb, {J}. and {C}ornou, {C}{\'e}cile and {G}erard, {J}. and {A}lmakari, {M}.},
  editor = {},
  language = {{ENG}},
  abstract = {{P}ost-seismic investigations repeatedly indicate that structures having frequencies close to foundation soil frequencies exhibit significantly heavier damages ({C}aracas 1967; {M}exico 1985; {P}ujili, {E}cuador 1996; {L}'{A}quila 2009). {H}owever, observations of modal frequencies of soils and buildings in a region or within a current seismic risk analysis are not fully considered together, even when past earthquakes have demonstrated that coinciding soil and building frequencies leads to greater damage. {T}he present paper thus focuses on a comprehensive numerical analysis to investigate the effect of coincidence between site and building frequencies. {A} total of 887 realistic soil profiles are coupled with a set of 141 single-degree-of-freedom elastoplastic oscillators, and their combined (nonlinear) response is computed for both linear and nonlinear soil behaviors, for a large number (60) of synthetic input signals with various {PGA} levels and frequency contents. {T}he associated damage is quantified on the basis of the maximum displacement as compared to both yield and ultimate post-elastic displacements, according to the {RISK}-{UE} project recommendations ({L}agomarsino and {G}iovinazzi in {B}ull {E}arthq {E}ng 4(4): 415-443, 2006), and compared with the damage obtained in the case of a similar building located on rock. {T}he correlation between this soil/rock damage increment and a number of simplified mechanical and loading parameters is then analyzed using a neural network approach. {T}he results emphasize the key role played by the building/soil frequency ratio even when both soil and building behave nonlinearly; other important parameters are the {PGA} level, the soil/rock velocity contrast and the building ductility. {A} numerical investigation based on simulation of ambient noise for the whole set of 887 profiles also indicates that the amplitude of {H}/{V} ratio may be considered as a satisfactory proxy for site amplification when applied to measurements at urban scale. {A} very easy implementation of this method, using ambient vibration measurements both at ground level and within buildings, is illustrated with an example application for the city of {B}eirut ({L}ebanon).},
  keywords = {{S}pectral coincidence ; {N}onlinearity ; {S}eismic damage ; {M}icrotremor ; {B}eirut ; {N}eural network ; {LIBAN} ; {BEYROUTH}},
  booktitle = {},
  journal = {{E}arth {P}lanets and {S}pace},
  volume = {69},
  numero = {},
  pages = {art. 60 [17 p.]},
  ISSN = {1880-5981},
  year = {2017},
  DOI = {10.1186/s40623-017-0641-3},
  URL = {https://www.documentation.ird.fr/hor/fdi:010070276},
}