Abstract
This paper summarizes a theoretical and laboratory investigation to develop a procedure to predict the cyclic undrained stress-strain-time behavior of cohesionless soils under irregular cyclic loading patterns. It was found that the maximum shear strain amplitude induced in sand under a given irregular cyclic loading pattern can be predicted from a knowledge of the stress-strain behavior of the sand for uniform cyclic loading by using the cumulative damage concept. However, the cumulative damage concept cannot adequately predict the strain-time history of sand, and a new analytical method accounting for the deterioration in the stress-strain characteristics of sand was developed to provide this information.Cyclic undrained simple shear tests on sand were performed using uniform and cyclic irregular loadings to confirm the theoretical evaluations. Theoretical results compared with the test results showed good agreement.
