Failure criterion for granular soils

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.