GeoCongress 2012

Numerical Insights into Liquefaction-Induced Building Settlement

Abstract

The effective design of earthquake resistant structures and liquefaction mitigation techniques requires an improved understanding of the consequences of liquefaction. To provide insight, a series of four centrifuge experiments were performed, which involved structural models founded atop a layered soil deposit that included a liquefiable layer. Results from these centrifuge experiments were utilized to evaluate the predictive capabilities of a state-of-the-practice numerical tool. Numerical simulations with the UBCSAND model implemented in FLAC-2D captured building settlements measured in these experiments reasonably well, mostly within a factor of 0.7 and 1.8. The soil model captured the overall contribution of deviatoric displacement mechanisms (i.e., SSI-induced building ratcheting and partial bearing failure) and localized volumetric strains during partially drained cyclic loading. The model was not able to capture all aspects of the soil's response to earthquake loading. In these experiments, it overestimated the extent of soil softening and building displacement for slower rates of earthquake energy buildup.