Abstract Research results show that rotation of principal stress axes (RPSA) has a large influence on the mechanical properties of soil. To study the mechanical and deformation properties of frozen saline soil under RPSA, in this paper, a constitutive model considering RPSA is proposed for frozen saline soil by considering the plastic deformation caused by the increase of principal stress amplitude and the plastic deformation caused by RPSA separately. The proposed model has the following properties: (1) For the part of principal stress amplitude increase, the critical stress ratio Mc(s)g(θ) changing with hydrostatic pressure is adopted to describe pressure melting and crushing phenomenon characteristic of frozen saline soil under high confining pressure. A function of plastic shear strain and plastic volumetric strain is taken as hardening parameter to control the size of the bounding surface under plastic volumetric compression mechanism. (2) Based on the experimental results, a new shape function is presented for frozen soil, and the proposed shape function is introduced into bounding surface function and plastic potential function to control the shapes change of bounding surface and plastic potential surface. (3) For the part of RPSA, a more accurate method for determining loading direction and a formula for solving non-coaxial angle are given. A plastic modulus formula considering the effects of hydrostatic pressure, generalized shear stress, and anisotropy is proposed. A dilatancy equation which can reflect the effect of intermediate principal stress coefficient is presented. By comparing the simulated results of the proposed model with the experimental results, it is found that the proposed model not only can reflect the effect of the increase of principal stress amplitude on the mechanical and deformation behaviors of frozen saline soil, but also can describe the effect of RPSA on the mechanical and deformation behaviors of frozen soil.

中文翻译：

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考虑主应力轴旋转的冷冻硫酸盐盐质粘土边界面模型

摘要 研究结果表明，主应力轴的旋转（RPSA）对土体的力学性质有很大影响。为研究RPSA作用下冻盐土的力学和变形特性，本文分别考虑主应力幅增加引起的塑性变形和RPSA引起的塑性变形，提出了一种考虑RPSA的冻盐土本构模型。 . 该模型具有以下性质： (1)对于主应力幅增大的部分，采用随静水压力变化的临界应力比Mc(s)g(θ)来描述冻盐土的压熔压碎现象特征。在高围压下。将塑性剪切应变和塑性体积应变的函数作为硬化参数来控制塑性体积压缩机制下边界面的尺寸。(2) 根据实验结果，提出了一种新的冻土形状函数，并将所提出的形状函数引入到边界面函数和塑性势函数中，以控制边界面和塑性势面的形状变化。(3)对于RPSA部分，给出了更准确的加载方向确定方法和非同轴角的求解公式。提出了考虑静水压力、广义剪应力和各向异性影响的塑性模量公式。给出了一个能反映中间主应力系数影响的剪胀方程。