Modified stress considering the fabric of soil particles and the elastoplastic constitutive model

As an aggregate of particles, soil changes its particle structure as a result of stress history. Even if the stress state and density are the same, the soil exhibits various behaviors depending on the differences in particle structure.

The fabric tensor, which represents the directional distribution of the particle contact normal, is known as an indicator of the particle structure. On the other hand, Nakai and Mihara (1984) proposed a modified stress tij using the normal tensor aij of a three-dimensional sliding surface in order to consider the effect of intermediate principal stress on strength deformation characteristics.

In this study, we focus on the similarity between the two and propose a new tensor quantity aij* and modified stress tij* using it by giving an evolution law that takes the stress history into account to aij, which is originally obtained from the stress only.

京川裕之, 菊本統, 中井照夫：修正応力を用いた等方硬化モデルによる誘導異方性の表現, 地盤工学ジャーナル, Vol. 5, No.4., pp.533-544, 2010年12月.