一种散粒体材料破坏准则研究

Failure criterion for granular soils

在Lade-Duncan准则和Matsuoka-Nakai准则的基础上,提出了适用于各种散粒体材料的新型破坏准则。该准则能够依据试验结果,调节准则方程中的参数,使得理论计算更加符合试验结果,这与传统的岩土类材料破坏准则相比有着较大优越性。通过构造三角恒等式,推导了π平面上距原点的长度函数,发现该准则在π平面上的形状则为光滑曲边三角形,这和大量的岩土类材料试验结果相符合。研究了该准则在一般应力状态下的内摩擦角与中主应力参数的关系,发现该准则能够取遍Lade-Duncan准则和Matsuoka-Nakai准则之间所有内摩擦角值。将各准则的计算结果与文献中已有的砾石料和中细砂的真三轴试验结果进行对比分析,表明所提出的准则要比Lade-Duncan准则和Matsuoka-Nakai准则更加符合试验结果,这进一步说明了该破坏准则能够适用于包括堆石料、砾石料、砂等散粒体材料。

A new failure criterion for granular soils is proposed to address the fact that the new criterion can adjust its parameters according to the experimental results in order to make agreeable predictions,while most criteria,including the Lade-Duncan criterion and the Matsuoka-Nakai criterion,can not agree well with the experimental results under general stress conditions.The distance function of the new criterion in π plane is deduced,and the shape of the new criterion in π plane is a triangular curve which is convex and smooth.The relationship between the internal friction angle and the intermediate principal stress parameter of the new criterion,which regards the Lade-Duncan criterion and the Matsuoka-Nakai criterion as its special cases,is presented.The results predicted by the new criterion are better than those predicted by the Lade-Duncan criterion and the Matsuoka-Nakai criterion compared with the experimental results of granular soils.So,the proposed criterion can be used for granular soils such as rockfill materials,gravel and sand.