Evaluation of Liquefaction Using Disturbed State and Energy Approaches

The disturbed state concept (DSC) and the dissipated energy approach can provide simplified, fundamental, and mechanistic methods for the identification of the initiation and growth of liquefaction in saturated soils under cyclic and earthquake loading. Both approaches are developed and used for the analysis of liquefaction in the soil deposits at Port Island, Kobe, Japan, during the Hyogo-ken Nanbu earthquake. They are also used to analyze liquefaction of two sands during laboratory cyclic tests using torsional and multiaxial devices. It is shown that the DSC and energy criteria can lead to improved understanding of the mechanism of liquefaction, and to rational and simplified procedures compared to those based on empirical and index properties. Furthermore, the DSC possesses certain advantages over the energy approaches, particularly in terms of its implementation in computer (finite-element) programs for dynamic and liquefaction analysis.