Simple Modeling of Stress-Strain Relation for Unsaturated Soil
Simple Modeling of Stress-Strain Relation for Unsaturated Soil
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DOI：
10.1061/41103(376)3
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发表时间：
2010-09
期刊：
影响因子：
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通讯作者：
H. Kyokawa;M. Kikumoto;T. Nakai;H. Shahin
中科院分区：
文献类型：
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作者：
H. Kyokawa;M. Kikumoto;T. Nakai;H. Shahin
非饱和土的应力-应变特性与饱和土的应力-应变特性有很大的不同，但在实际工程中，土往往处于非饱和状态，因此，非饱和土的应力-应变特性需要用土的本构模型来描述。本文将一个简单的饱和土弹塑性模型推广到非饱和土。建议的模型是制定使用主教的有效应力和剩余强度，因此，假定为常数。该模型将饱和度的减小（或增大）与平均有效应力和孔隙比压缩面内正常固结线的上移（或下移）联系起来，较好地描述了非饱和土的典型体积性状和变形性状。此外，一个简单的方法来扩展经典的水分保留曲线，如货车Wenchten的方程，能够将吸力的历史和密度的影响，提出并应用到所提出的模型。在本文中，该模型的轮廓解释和模型的适用性进行了讨论，通过典型的模拟结果。
Though stress-strain characteristics of unsaturated soils are complicated and rather different from those of saturated soils, it should be described properly by a constitutive model for soils because soil usually stays under an unsaturated condition in actual field. In the current study, a simple elastoplastic model for saturated soil is extended to one applicable to unsaturated soils. The proposed model is formulated using the Bishop’s effective stress and the residual strength is, therefore, assumed to be constant. In the proposed model, the decrease (or increase) in the degree of saturation is linked with upward (or downward) movement of normally consolidated line in the compression plane of mean effective stress and void ratio, by which the typical volumetric and distortional behaviors of unsaturated soils are properly described. In addition, a simple method to extend classical water retention curves such as van Genuchten’s equation to be able to incorporate the influences of suction histories and density is proposed and applied to the proposed model. In the present paper, the outline of the proposed model is explained and applicability of the model is discussed through typical results of simulations.