The Triple-Shear Unified Structured Constitutive Model For Saturated Clay Based On The Disturbed State Concept

The soils has a certain structure in the natural state.The structure of soils,refers to the arrangement of the soil grains and the pore,and the interaction between the soil grains.The mechanical properties of soils is influenced by the structure deeply.The structure of soils is affected by various factors such as the arrangement.At present most of the constitutive models of soils are based on the remolded soils,and the constitutive models neglect the structure of soils.With the development of the computer programming,if the constitutive model can be established,the stress and strain curves of soils can be simulated by computer easily.So it is the most important problem is to establish the constitutive model that considering the structured soil.Based on the disturbed state concept and the modified cam-clay model,and the structured constitutive model of saturated clay is established.The triple-shear unified yield criterion is used in the new constitutive model.The modified of soil failure ratio M by using the method of equicalent substitution and coordinate translation.The structural constitutive model considering the intermediate principal stress effect parameter b.imply on the three-dimensions in order to show the stress-strain relationship under six-dimensions.The parameters of the soil parameters and constitutive model are obtained through a large number of laboratory soil tests and conventional triaxial tests to saturated undisturbed laterite in Jiangxi.The characteristic curves of mechanical and deformation properties are got by conventional three axis tests and K0 consolidation tests in different drainage conditions.The influence of the structure on strength and deformation characteristics of the soil is explained emphatically.The programs of the new constitutive model is compiled by Fortran9.0.The relationship between stress and strain of soil and its variation are simulated through conventional three axis tests,0K consolidation tests and true triaxial tests.The rationality and accuracy are verified by comparing the test and numerical results of equal replacement method and translating coordinate.Moreover,the influence of the middle principal stress on the new constitutive model is studied.