Author:
Cappellaro Claudio,Dhakal Riwaj,Cubrinovski Misko
Abstract
Severe liquefaction-induced damage occurred in reclamation fills at the port of Wellington (CentrePort) in the 2016 Kaikōura earthquake, but little or no damage was reported in areas of older and shallower reclamations in central Wellington. Recent studies have therefore primarily focused on understanding the liquefaction hazard of the port, while little is still understood with regards to the fill characteristics and liquefaction potential of the Wellington reclamations outside CentrePort. This study utilizes data from comprehensive field investigations, including 58 new cone penetration tests (CPTs) performed both within and outside the port in the Wellington waterfront area, supplemented with over 100 CPTs from our previous studies at CentrePort, to characterize the liquefaction resistance of the reclaimed fills in Wellington. The geotechnical data is first used to define simplified schematic soil profiles and to determine characteristic CPT parameter values (25th–50th–75th percentiles) for fills encountered in different reclamation areas. These analyses highlight differences in the soil profiles, and the relative similarity in the estimate of liquefaction resistance based on conventional CPT-based assessment, of fills encountered in different reclamation areas despite differences in the age, techniques, and materials employed in the construction of these reclamations. Conventional liquefaction assessments of reclamation fills based on CPT data are then performed over the wider waterfront area for a range of earthquake scenarios and ground motion intensities relevant for Wellington. For recent, past earthquakes, correspondence between predicted and observed severity of the manifestations of liquefaction vary depending on the earthquake event and area of observations. Likelihood of liquefaction occurrence and severity of the effects of liquefaction are then discussed for characteristic return periods, in the context of the seismic hazard of Wellington.
Publisher
New Zealand Society for Earthquake Engineering
Reference72 articles.
1. Cubrinovski M and Dhakal R (2021). “Identification and mitigation of seismic hazards from inherited vulnerabilities”. 17th World Conference on Earthquake Engineering, 27 September-2 October 2021, Sendai, Japan.
2. Cubrinovski M, Bray JD, de la Torre C, Olsen MJ, Bradley BA, Chiaro G, Stocks E and Wotherspoon L (2017). “Liquefaction effects and associated damages observed at the Wellington CentrePort from the 2016 Kaikōura earthquake”. Bulletin of the New Zealand Society for Earthquake Engineering, 50(2): 152-173. https://doi.org/10.5459/bnzsee.50.2.152-173
3. USGS (1990). “Effects of the Loma Prieta Earthquake on the Marina District, San Francisco, California”. Open File Report 90-253, Dept. of the Interior, U.S. Geological Survey, Menlo Park, CA, United States. . https://doi.org/10.3133/ofr90253
4. Seed RB, Dickenson SE and Idriss IM (1991). “Principal geotechnical aspects of the 1989 Loma Prieta earthquake”. Soils and Foundations, 31(1): 1-26.
5. https://doi.org/10.3208/sandf1972.31.1