Post-seismic settlement mitigation for a building in Richmond, B.C.

Mustapha Zergoun, Ivan River Cruz

In the proceedings of: GeoSt. John's 2019: 72nd Canadian Geotechnical Conference

Session: Foundations

ABSTRACT: This paper describes the ground improvement scheme implemented to mitigate post-seismic settlement of a building in Richmond, British Columbia. The site topography is flat and below the expected regional flood level. The site is in a seismically active zone with shallow groundwater level. The subsoil stratigraphy includes loose sand deposits which are potentially liquefiable under a strong seismique event. The building foundations consisted of spread footings and the soil liquefaction mitigation included vibro-replacement soil densification. Due to site and economic restraints, the mitigation scheme did not extend to the full depth of the potentially liquefiable soils and its lateral extent was limited to the building perimeter. Therefore, vertical seismic drains were installed along the building perimeter to mitigate potential adverse effects on the building due to excess pore pressure generated during an earthquake. The paper outlines how the soil densification target criteria were established and points out the limitations of the vibro-replacement method. The paper describes the methods available to assess the building post-seismic settlement.

RÉSUMÉ: Cet article décrit lpost-sismique un bâtiment à Richmond, Colombie-Britannique. La topographie du site est plate et en-dessous du niveau prévu de crue régionale. Le site est dans une zone sismique eau est proche de la surface. La stratigraphie des sols inclut un dépôt de sable lâche qui est potentiellement liquéfiable en cas dséisme. Les fondations du bâtiment consistaient mélioration du sol contre la liquéfaction comprenait la densification des sols par vibro-remplacement. En raison des contraintes dues au site et des conditions mélioration es sols liquéfiables et son étendue latérale était limitée au périmètre du bâtiment. Par conséquent, des drains verticaux ont été installés le long du périmètre du bâtiment pour atténuer la liquéfaction des sols sous le bâtiment. Cet article montre comment le critère de densification des sols a été établi et montre les limites de la méthode de vibro-remplacement. Cet article décrit les méthodes disponibles pour estimer le tassement post-sismique du bâtiment.

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Cite this article:
Mustapha Zergoun; Ivan River Cruz (2019) Post-seismic settlement mitigation for a building in Richmond, B.C. in GEO2019. Ottawa, Ontario: Canadian Geotechnical Society.

@article{Geo2019Paper567,author = Mustapha Zergoun; Ivan River Cruz,title = Post-seismic settlement mitigation for a building in Richmond, B.C. ,year = 2019}