Cyclic loads frequently are a non-destructive operation. The resulting de-formations of the cyclic load is different from the static load deformation. The reaction of the soil to cyclic loading requires a different description because of the possibility to differentiate the size of plastic deformation and elastic in one load cycle. The reaction of cyclically loaded cohesive soil is affected by many factors such as the degree of saturation, over-consolidation ratio or density. Conditions in which the soil is subjected to a load such as the size of the principal stress (σ3), value of the deviatoric stress (qmax) or stress amplitude (σa) in the case of repeated loads lead to different reaction cohesive soil. The article presents results of research on cohesive soil namely sandy – silty caly. The study was conducted using a cyclic triaxial apparatus. The objective of this study was to characterize the stress causes a different reaction cohesive soil. The article presents the methodology of research and analysis of the behavior of the soil. Also it proposed empirical equation for determining the growth of plastic deformation in subsequent cycles load.

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