砂土的密度相关状态参量的划分及分析

Strength and deformation of soil is closely related to its density, so density or density⁃related physical quantity should be considered as a state parameter to reflect its influence on stress⁃strain relationship. Hence, according to their characteristics, the state parameters are divided into initial porosity ratio e₀, relative porosity ratio γ based on normal compression line or overconsolidation ratio OCR, relative porosity ratio ψ based on critical state line and relative porosity ratio ξ based on dynamic anisotropic compression line, and the relationship and difference between the state parameters are analyzed. It is proved that sand has a unique NCL and its initial point coincides with CSL. The state parameter ξ takes the anisotropic compression line covering NCL and CSL as the reference line, and corrects the problems that the state parameter ψ is not applicable to isotropic compression, K₀ compression or other stress paths. Based on CSUH model, the influence of state parameters ψ and ξ on the calculation results under different stress paths is analyzed. The results show that compared with the state parameter ψ, the stress⁃strain relationship calculated by CSUH model with the state parameter ξ is more suitable for various complex stress paths.