In pavement design, the CBR and direct shear tests are two very common laboratory investigations for predicting the strength of a subgrade layer. The relationship between the CBR and water content has been commonly presented in analyses, with the result of the direct shear being expressed from the aspect of effective cohesion and the internal friction angle. Even though most natural soil is in...

Prediction method for undrained shear behaviour of unsaturated soils is discussed in this paper. Based on Original Cam Clay model, authors have proposed constitutive model for unsaturated soils that the effect of water content is incorporated into superloading surface concept. Firstly, stress path of constant volume shear test is formulated under constant void ratio condition. And relationship ...

This study focuses on investigation of the undrained shear strength unsaturated frozen silts prepared at varying initial thermal and hydraulic conditions. The degree saturation controls ice unfrozen water contents temperatures below depression point. properties soils are highly influenced by which is coupled with state soils. To evaluate silts, a series direct simple experiments were performed ...

This paper presents an overview of elasto-plastic modelling of unsaturated soils. Alternative stress and strain variables that have been used in constitutive models for unsaturated soils are discussed. The use of an effective stress equation may simplify constitutive relations, but often result in a stress space that depends on the material state. In this case, the constitutive behaviour is emb...

In slope engineering, soils are commonly at unsaturated state. The question of how to apply unsaturated soil mechanics theory to the slope stability analysis has become a hot spot in today’s geotechnical engineering research. Based on the experimental research of how shear strength of residual soil varies with water content, reasonable computation modules can be created. By using limit equilibr...

A new simple shear apparatus is fabricated which is capable of applying monotonic and cyclic load on soil specimens. A series of tests was conducted to study the pore pressures (or suction), volume change, and shear behavior of the soil samples with anisotropic consolidation pressure. The simple shear apparatus is capable of controlling as well as measuring pore-air and pore-water pressure in t...

There has been a proliferation of equations proposed to describe the unsaturated shear strength envelope going back 1970s. However, there have limited studies verify suitability one equation over another. Most attempted relate an soil some aspect(s) soil–water characteristic curve (SWCC). Estimation procedures generally focused on using that air-entry value (AEV) as defined by drying (or desorp...