ABSTRACT
Dynamic effective stress analysis (ESA) is performed to back-analyze the seismic responses of a liquefiable site in Christchurch during the 2010-2011 Canterbury earthquake sequence. Different amounts of ejecta were observed at this site after earthquakes of different intensities and durations. The severity of liquefaction manifestations is used to assess the capability of ESA for estimating the likelihood and amount of ejecta. The ESA employs the PM4Sand and PM4Silt constitutive models after they were calibrated to capture the contractive-dilative response of liquefiable materials at the site. The simulation results show there is a unique trend between the computed excess pore water pressures and total head distributions to the severity of ejecta observed. The different patterns of the total head distribution generated by the earthquakes show promise as the basis for developing a methodology to estimate the amount of ejecta.
