The Stress-strain Behaviour Characteristics of the Decomposed Granite Soil in Cheongju District

This paper aimed at predicting the behaviour of characteristics of stress-strain to the decomposed granite soil at Cheongju district. Sample is weathered granite soil, then it is non-homogeneous and anisotropic as well as very various. To analyze geotechnical properties, isotropic compression test and cylinderical triaxial compression tests are performed under drained and undrained condition. At this time it was maintained compaction energy of 95% on the laboratory testing in order to regulate fracture effect by virtue of the compaction. The behaviour of stress-strain relationships were predicted using elasto-plastic constitutive model with single and double yield surface proposed by Lade. On the prediction analysis of the stress-strain behaviour, the slope of early stress state of double work hardening model is bigger than its slope of single model in behaviour of the undrained condition, but deviator stress of single model is bigger than double model in failure.