Abstract: A new constitutive model of sand considering complex stress path has been proposed. It offers an insight into a fact that, with the mean stress p a little changed, stress ratio is the essence that stress path influences the stress-strain relation of sand. When calculating the stress-strain relation using this model, the stress path is linearized in order to calculate respectively the strain on the mean stress path and equal stress ratio path. The test results accord with the theoretical prediction of pretty well, which proves the rationality of the way the model uses the function . The comparison between prediction and test results under the condition of complex stress path reflects that the model can rationally consider the influence of stress path on the stress-strain relation.

Key words: stress path, constitutive model, three-dimension, tests, sand