关键词: 地基沉降, 大变形, 本构关系, 有限应变, 切线体积压缩系数

Abstract:

Aimed at the controversy on the results of ground settlements predicted both by large-strain and small-strain methods, the significant concepts of finite-strain stress and strain measures, constitutive relations and related parameters etc., are investigated. Based on fundamentals of continuum mechanics, the large-strain settlement formula in respect to Green strain, Almansi strain, and natural strain are presented. The large-strain constitutive relationship of soil compression is proposed with respect to Euler stress – Almansi strain pair and Euler stress – natural strain pair. A transform method between the tangent volume compressibility coefficients using large-strain and small-strain schemes is put forward. The theoretical analysis and the corresponding case study show that the computational settlements by large-strain and small-strain methods should be identical in the case of strictly following the presented transform method; otherwise the value of large-strain settlement might be over or under that of small-strain method. The transform method can also provide new reference for determining reasonably the large-strain constitutive parameters.

Key words: foundation settlement, large deformation, constitutive relation, finite strain, tangent volume compressibility