三向应力及湿度状态改变对非饱和黄土力学特征的影响

Influence of Spherical Stress and Humidity State on Mechanical Property of Unsaturated Loess

通过对黄土常规三轴试验结果分析,给出了非饱和黄土的强度参数随含水量的指数型变化关系式,并验证了D-P屈服准则对不同湿度状态下黄土发生塑性屈服的适用性。不同三向应力条件和温度状态下的压缩试验表明,Q3黄土的应力应变关系随着三向应力和含水量而变化,这种本构关系可以用一个简单的指数函数来描述。与已有的模型相比,基于室内试验提出的半经验型黄土本构关系具有模型简单、参数少、易确定的优点。

The exponential functions of unsaturation loess strength parameters changing with water content are given after analyzing the results of convention tri-axle test, and the suitability of D-P criterion to decide plastic yield of loess in different humidity states is also verified. The loess compress test result shows that the stressstrain relationship of loess varies with spherical stress and humidity condition. The constitutive relation of Q3 loess can be described by a simple exponential function. A constitutive model is advanced based on testing in laboratory and comparing with the constitutive model offered in other documents, the model not only has less parameters and is easy to be determined, but also is simple.