LIQUEFACTION RESISTANCE FROM A DUCTILITY VIEWPOINT

MOTOKI KAZAMA, AKIRA YAMAGUCHI and EIJI YANAGISAWA

ABSTRACT Very few attempts have been made to evaluate the liquefaction resistance from a ductility viewpoint. The authors propose a new method to evaluate the ductility of soils against liquefaction, based on the energy dissipation capacity obtained from stress-strain loops of the constant-strain-controlled cyclic triaxial test. The method makes it possible to evaluate the liquefaction resistance against large earthquakes like the 1995 Hyogoken-Nambu earthquake. The effectiveness of the proposed method is explained using the test results of various soils. To confirm its effectiveness, a comparison was made of the energy dissipation capacity for Masado soil on Kobe Port Island obtained from the cyclic triaxial test, the array observation data and the seismic response analysis. The energy dissipation capacity obtained from the above three procedures shows very consistent results.

Key words: array observation, cyclic triaxial test, decomposed soil, dissipation energy, ductility, Hyogoken-Nambu earthquake, liquefaction resistance, Masado, strain-controlled test (IGC: E8/D7)