ABSTRACT
An elastic visco-plastic (EVP) constitutive equation for a natural structured clay is presented in consideration of strain rate effect and structure damage. The constitutive equation is derived based on Shen’s masonry damage theory and reference time line concept in Yin & Graham’s EVP model. The new modelling results are compared with experimental results from drained and undrained triaxial compression tests with several strain rates. The critical strain rate and the critical-strain-rate effect found in the tests are interpreted and demonstrated in the modelling. The proposed model has nine material parameters, which can be determined by traditional oedometer confined and triaxial compression tests.
