| The structure and rheological properties of soft clay have important influence on its consolidation behavior. At present, there isn't a consolidation theory that can reflect this two properties during the process of consolidation of natural soil, and so it is important to do research on the structure and rheological properties of soft clay. In this dissertation, a new one-dimensional elastic viscoplastic consolidation model is established based on the analytic result of consolidation of the structured soft clay, and by using this model, the consolidation behavior of the natural clay and disturbed clay are analyzed systematically.In order to establish a more rational consolidation model, the structure and rheological characteristics during the process of consolidation are across-the-board studied on the basis of the existing experimental data. The research indicate that the structured soft clay has below several characteristic, the viscous strain is produced during the stage of primary consolidation and of second consolidation, and in the prophase, the relation of stress-strain-strain rate is unique, so the form of constitutive model, such as, F(σv',e) = 0,F(σ'v,e,t) = 0, can't describe strain behavior of soil skeleton rationally; The time-dependent properties involve three aspects, in addition the time-dependent strain, apparent preconsolidation pressures that depend on strain rate, and the effect of creep compression on apparent preconsolidation pressures; Because of holding structural strength, the mechanics characteristic is determined by the magnitude of stress, and the compression curve is composed of several sections.By combining structural yield stress and it's characteristics with the improved time line model, a new one-dimensional elastic visco-plastic consolidation model is established. The results of simulation indicate that the new model can think the three time-dependent properties and subsection of compression curve, and can be applied to any loading manner. The model parameters can be gained from eight fundamental parameters, such as e0, k, Cεr,Cεc,Cεa,σ'0 (original effective stress), σp0-ref(apparentpreconsolidation pressure under the condition of the traditional consolidation test) and εp0-ref(strain rate while the effective stress equal to the apparent preconsolidationpressures), which can be easily gotten from traditional experiments. The new model is also compared with early models, and validated by known experiments data, and the mechanism of strain and the method of finite difference are given.Based on the new model, the influences caused by soil structure, apparent preconsolidation pressure, the re-compression index, the coefficient of secondary compression, the magnitude of loading, the coefficient of permeability, the rate of loading, the thickness of clay, the self-weight, the layered property etc, in the process consolidation of soil with structure, are analyzed in detail. The difference between the present model and Yin & Graham model was also given.Based on the analysis of soft soil structure characteristics, a new conception of degree of sample disturbance and quantitative relation between the degree of sample disturbance and its parameter are put forward. The analytical solution indicate that, the disturbance has a important influence on the behavior of structured soft clay, and, with the increasing of disturbance degree, and strain is added, but the dissipation of pore pressure is decelerated.Finally, two examples show that, the availability and practicability of the new model is verified. The analysis of calculation result of Berthiervill test embackment shows different part of compression curve have different influence upon the course of consolidation, and correct coefficient and viscous effect have great significance on deformation forecast. Associated with the wenzhou airport runway engineering, the reason of increasing of pore-water pressuer in under-lying soft layer and post-construction settlement are given.
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