ABSTRACT
The key aspect controlling liquefaction induced displacements is the fundamental stress-strain response of the liquefied soil element. Cyclic stresses imposed by the earthquake cause the soil element to experience a large drop in stiffness and strength. A soil structure comprises a collection of such elements, and its response can be computed from the laws of mechanics once the element stress-strain behaviour is known. Characteristic liquefaction response based on cyclic element tests is reviewed. Empirical and mechanics based methods for estimating liquefaction induced displacements are also discussed. The empirical methods are considered to represent a database of field experience, and have been used to verify the mechanics based methods. Two case histories (Mochikoshi Dam No. 1 and La Marquesa Dam) are evaluated using the mechanics approach. Good agreement between the analyses and the field observations is obtained, both in terms of magnitude and pattern of displacement.
