CORRELATING CYCLIC STRENGTH WITH FINES CONTENTS THROUGH STATE PARAMETERS

Abstract

Attempts have been made in the past few decades to establish an equivalent void ratio indicative of the effective density state of sands that contain fines. The concept of an equivalent void ratio is most useful when the grain size distribution of the sand/silt mixture is similar to that of binary packing. Due to its grain characteristics and the wide range of compressibility when the fines content changes, correlating the cyclic strength to fines content via the equivalent void ratio for Mai Liao Sand (MLS) is not a straightforward procedure. Earlier studies have demonstrated the effectiveness of relating cyclic strength to state parameters for sands. Using a series of cyclic triaxial test results as a database, the authors demonstrated the effectiveness of relating cyclic strength to fines contents (f_c) through a state parameter for MLS with an f_c ranging from 0 to 30% that takes advantage of the equivalent void ratio. In addition to the density and stress states, the state parameter based correlations indirectly reflect the effects of soil grain characteristics. The drawback of requiring a separate critical state line when f_c changes can be circumvented by using a unified critical state line based on the equivalent void ratio.