The critical states of saturated loess soils

Highlights

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The detailed shearing behaviour of loess specimens depends on the combination of v_i and ${p_0}^{\text{'}}$.

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The plasticity index and particle gradation parameters of loess do not appear to significantly affect the M value.

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The intercept Γ and gradient λ of CSL against grading indices has an overall liner trend.

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The intact loess generally has a higher liquefaction potential.

Abstract

This paper presents an experimental investigation on eleven loess soils retrieved from NW China to explore the influence of grading and age on soil mechanics. There are overall consistent characteristics in stress-strain relationship and stress paths for the loess tested though detailed property depends on the combination of v_i and ${p_0}^{\text{'}}$. The critical state parameters are quantitatively analyzed against the soil properties. The critic state line (CSL) in p^' − q plane is less variable. The M value of specimens tested varies from 1.15 to 1.41 and the corresponding φ_cs^' is between 28.8° and 34.8°, which is not clearly related to the loess grading and plasticity index. In the volumetric plane, the intercept Γ of CSLs varies from 1.63 to 2.17 and the gradient λ of loess fall within a narrow range of λ = 0.08 ± 0.03. The λ linearly increases with the increasing plasticity index I_p. The intercept Γ and gradient λ against grading indices has an overall liner trend, i.e., decrease with the increase of D₅₀ and increase with the increasing C_u and C_c values. The intact loess usually has a higher I_B value, roughly between 0.5 and 0.9, indicating a relatively high liquefaction potential.