Super Loading Yield Surface Concept for the Saturated Structured Soils
“Superloading surface concept” is newly developed for the description of elasto-plastic behavior of highly structured soils. The superloading surface, which is similar in shape to the original Cam-clay yield surface, is located above the Cam-clay and the size ratio between two yield surfaces gives the degree of the structure of soil skeleton. The evolution law of the size ratio describes the decay of the structure as plastic deformation proceeds, and the superloading surface falls exactly on the Cam-clay yield surface at the end of the completely remolded state. When the soil is reloaded after elastic unloading, the elasto-plastic behavior of the soil is described by the Hashiguchi’s subloading surface, which is also similar in shape to the superloading surface. The size ratio between super and subloading surfaces gives the OCR.
The one dimensional consolidation deformation is numerically solved by the use of super subloading Cam-clay model, in which “secondary consolidation” is naturally observed. The reason for which can be found simply because the delayed collapse of the structure of soil skeleton leads the delayed compression/consolidation.
KeywordsYield Surface Stress Path Excess Pore Pressure Soil Skeleton Critical State Line
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