МОДЕЛЬ ЛЕССА, УЧИТЫВАЮЩАЯ ХАРАКТЕРИСТИКИ СТРУКТУРЫ И АНИЗОТРОПИЮ A constitutive model for loess considering the characteristics of structurality and anisotropy

Аннотация

Представлена модель лесса, основанная на модифицированной модели Cam-clay, в которую вводятся параметры структуры и анизотропии. Новая модель имеет восемь параметров, которые могут быть получены с помощью обычных лабораторных испытаний. Сравнение результатов трехосных испытаний показывает преимущества этой модели при расчете напряженно-деформированного состояния естественного ненарушенного лесса.

Полный текст статьи публикуется в английской версии журнала
«Soil Mechanics and Foundation Engineering” vol.59, No.1

Natural undisturbed loess has unique characteristics of structurality and anisotropy. How to reflect their influence in the constitutive model is the key to simulating its mechanical behavior accurately. In this paper, a new model of structural and anisotropic loess was presented based on the modified Cam-clay model. The structural parameter  is introduced into the  plane to show the structural properties of natural loess. The anisotropic parameter  is introduced through yield surface rotation to reflect the anisotropy of natural loess. The model hardening law considers the influence of anisotropy. The associated flow rule, combined with the consistency condition, is used to derive the incremental stress-strain relationship and establish a new model with the effects of structurality and anisotropy considered. When the two properties are not considered, the model is reduced to the modified Cam-clay model. The new model has a total of 8 parameters, which can be obtained through routine laboratory tests. A triaxial test is conducted by selecting natural undisturbed loess. A comparison between the experimental results and calculated results shows that the new model considering structurality and anisotropy is better than the modified Cam-clay model in simulating the stress-strain characteristics of natural undisturbed loess.