Optimum geosynthetic-reinforcement effect for unsaturated soil structures and evaluation of quality change with time

建立了复合土工合成结构模型，讨论了土工合成材料约束土体变形所产生的加筋效应。对土工合成材料包裹的压实砂土进行了一系列压剪试验，以定量检验土工合成材料加筋对压实土在剪切过程中变形的约束作用。在此基础上，提出了一种压实土的弹塑性模型和弹塑性模型所需输入参数的合理确定方法。然后，为了描述压实土在剪切过程中的不可逆变形特性，将次加载屈服面引入弹塑性模型。由于压实土本质上是非饱和的，其力学性质受工作在压实土介质中的吸力的影响，因此在判断压实度时考虑了吸力效应。最后进行了弹塑性有限元模拟，给出了土工合成材料的加筋效果。

The modeling of the composite soil-geosynthetic structure is presented and the effect of the reinforcement arising from the confining of the deformation of the soil by geosynthetics is descussed. A series of compressive shear tests for compacted sandy soil specimens, wrapped in geosynthetics, is carried out for the purpose of quantitatively examining the effect of the geosynthetic reinforcement arising from the confining of the deformation of compacted soils during shearing. Furthermore, an elasto-plastic modeling for compacted soil and a rational determination procedure for input parameters, needed in the elasto-plastic modeling, are presented. Then, the subloading yielding surface is introduced to the elasto-plastic modeling in order to describe the irreversible deformation characteristics of compacted soil during shearing. Since compacted soil is essentially unsaturated and its mechanical behavior is influenced by the suction working in the compacted soil media, the suction effect is taken into account in estimating of the degree of compaction. Finally, an elasto-plastic finite element simulation is conducted and the geosynthetic-reinforcement effect is presented.