The Use of Dissipated Energy in Cyclic Mobility Modeling

A short-term flow, kind of softening of soil during cyclic loading, makes a perceivable impact on strain progression in saturated soil during cyclic loading. A short-term flow developed during cyclic mobility of soil can be seen from the stress-strain relationship observed during cyclic triaxial tests. After few cycles of loading soil starts to exhibit very low stiffness at the beginning of a load cycle and it strengthen latter. It is obviously that strain developed during this short-term flow presents the main share of a total strain developed during cyclic loading and it leads therefore the deformation behavior of a soil. The duration of this phenomenon and stiffness of soil during this phase is in the question. The paper describes energy dissipation during this short-term flow phase. The duration of this phase, as well as shear modulus of soil during the softening phase were studied. Besides the short-term flow duration, also the pore pressure changes are effected by dissipated energy. Energy dissipated during the cyclic loading in saturated soil presents the parameter which enables a simple way of soil behavior modeling.