Abstract
The presence of a non-liquefied crust overlying a liquefied layer has been found to have a significant effect on sand ejecta and surficial liquefaction damage, as observed by Ishihara (1985). Following the 2010-2011 Canterbury seismic sequence in New Zealand, almost no foundation deformation occurred in areas with liquefaction susceptible soils overlain by at least a 3 m-thick crust [3]. In contrast, the 2012 Emilia-Romagna earthquake in Italy provided surface evidence of liquefaction despite 6- to 10 m-thick crusts. Several researchers have proposed liquefaction prediction models [e.g. LPI [6], Ishihara Curves [8], LSN [9], LPIISH [10] and the methods proposed by Towhata, et al. [11] and Hutabarat and Bray [12]]. Data from 2000+ Cone Penetration Tests (CPTs) were used to evaluate these methods for the 2012 Emilia-Romagna earthquakes to determine their effectiveness at predicting liquefaction surface ejecta manifestations. LPI was able to correctly predict the most liquefaction manifestation sites, however, LPI predicted a liquefaction surface ejecta manifestation for many sites that did not have a manifestation. The results from LSN were similar to LPI but were not able to predict as many liquefaction manifestation sites, and still had a large number of overpredictions. The method proposed by Hutabarat and Bray (2022) showed potential to perform better than LSN, but because of the binary nature of the output, only one threshold was able to be assessed. The Ishihara Basic and Cumulative methods had a median performance, but the Cumulative method was able to capture more true manifestation sites than the Basic method. The Towhata method performed nearly randomly in each of the statistical methods evaluated.
Degree
MS
College and Department
Ira A. Fulton College of Engineering; Civil and Environmental Engineering
Rights
https://lib.byu.edu/about/copyright/
BYU ScholarsArchive Citation
Flinders, Holten T., "The Assessment of Liquefaction Surface Ejecta Predictions on a New Large Dataset from the 2012 Emilia Romagna, Italy Earthquakes" (2024). Theses and Dissertations. 11119.
https://scholarsarchive.byu.edu/etd/11119
Date Submitted
2024-12-10
Document Type
Thesis
Keywords
Liquefaction, Cone penetration tests, Surface manifestation
Language
english