Numerical Method in Modeling the Elastoplastic Constitutive Relationship of Sand Under the Path of Constant Proportion of Principle Stress

Based on the numerical method modeling the constitutive law of rock and soil and the elastoplastic constitutive relationship of sand under the path of constant proportion of principle stress are established. The yield lines of plastic volum etric strain and plastic generalized shear stain are given. The constitutive mo del provides an exact constitutive equation for this k ind of engineering, which reflects the effect of practical stress path occurred in soils. Also, by comparing the stress-strain surfaces and yield locus of thre e stress paths, it is found that the difference among three stress paths are obvious, which demonstrates the influence of stress path on constitutive l aw can not be neglected.