화강토의 이방특성 연구 = A Study on the Anisotropic Characteristics of Weathering Granite Soil

다국어 초록 (Multilingual Abstract)

Weathering granite soil is the typical residual soil in Korea and it is known as a problematic soil because the strength characteristics is changed significantly when it is exposed to air and mixed or contacted with water. the aim of this study is to evaluate its strength characteristics.
The three-dimensional anisotropic strength characteristics of weathering granite soil was examined using cubical triaxial tests with independent control of the three principal stresses. The cubical triaxial tests were performed with various values of 'b'=(σ2 - σ3) /(σ1 - σ3).
In the cubical triaxial tests, it was found that the slope of the stress-strain curve increased and the rate of dilation decreased and major principal strain at failure decreased with increasing value of 'b'. The adjusted effective friction angles obtained by the stress state projected on octahedral plane turned out to fit Lade's failure criterion well.
The strain increment vectors are generally not perpendicular to the failure surface in the octahedral plane. This implies that anisotropic weathering granite soil follows with non-associate flow rule.
The intermediate principal stresses have an effect on the three-dimensional strength of anisotropic weathering granite soil, therefore the effects of the intermediate principal stresses should be considered in failure criterion.