Stress-strain transformations and liquefaction of sands

Abstract

Presented in this paper are the results of the laboratory tests of sands performed for the purpose of defining the characteristics of the dynamic shear stress-shear strain relationships. For this purpose, the transformation of the initial stress-strain characteristics of undrained saturated sands was investigated separately. These transformations take place under conditions of an increase in pore pressure under the effect of sufficiently intensive dynamic excitations. The process of occurrence and development of liquefaction was investigated simultaneously. The obtained results show that the transformation of the stress-strain relationships leads to intensive reduction in the initial dynamic characteristics of sands. At the moment of occurrence of initial liquefaction, for the selected strain, shear moduli are considerably reduced in respect to their initial values. These parameters tend to be further reduced in the phase of post-initial liquefaction. It is concluded that the process of liquefaction of sands can be completely defined through the transformation of the stress-strain relationships.