System response of liquefiable deposits

• Published in: Soil dynamics and earthquake engineering (1984) Vol. 124; pp. 212 - 229
• Main Authors: Cubrinovski, Misko, Rhodes, Aimee, Ntritsos, Nikolaos, Van Ballegooy, Sjoerd
• Format: Journal Article
• Language: English
• Published: Barking Elsevier Ltd 01.09.2019; Elsevier BV
• Subjects: Case histories; Case history; Damage assessment; Earthquake; Earthquake damage; Earthquakes; Effective stress; Effective stress analysis; Liquefaction; Seismic activity; System response; Effective stress analysis; Earthquake; Liquefaction; System response; Case history
• ISSN: 0267-7261; 1879-341X
• DOI: 10.1016/j.soildyn.2018.05.013

Detailed geotechnical characterization and in-depth liquefaction assessment using seismic effective stress analyses are presented for 55 liquefaction case histories (sites) from Christchurch. Fifteen of the sites manifested liquefaction in the two major earthquakes during the 2010–2011 Canterbury earthquakes (YY-sites), while 17 sites did not manifest liquefaction in either event (NN-sites). The YY- and NN-sites are shown to have practically identical critical layer characteristics, with low CPT tip resistance (qc1Ncs = 80–86), and shallow location of the critica.l layer at approximately 2 m depth. However, there are significant differences between the YY- and NN-sites with regard to their deposit characteristics including the thickness and vertical continuity of their critical zones and liquefiable materials. Effective stress analyses are used to demonstrate key mechanisms of system-response of liquefying deposits that either intensify (for the YY-sites) or mitigate (for the NN-sites) liquefaction manifestation at the ground surface. The study illustrates the need to consider system-response of liquefying soils in the assessment of liquefaction manifestation and severity of liquefaction-induced damage. •System response effects of liquefiable deposits have governing influence on liquefaction manifestation at the ground surface.•System response effects increase the severity and consequences of liquefaction manifestation for YY-sites.•A set of cascading mechanisms produce system response effects that mitigate liquefaction manifestation for NN-sites.•Simplified liquefaction evaluation procedures ignore system response of liquefiable deposits.