On the Shear Strength and Moisture Suction Property of Residual Granitic Soils after Soaking

Studies on physical properties of residual soils (3)

Abstract

The physical properties of residual soils vary with soaking. In this paper, we have described the influence of soaking on the shear strength and pF moisture property of residual granitic soils.
The results are summarized as follows:
1) By soaking, strength parameter C_u and tan φ_u of sandy soils, such as Kitayama soil decrease to about 50% in a dry and loose condition.
2) Strength parameter C_u and tan φ_u of fine-grained soils, such as Omishima soil show a remarkable decrease, occasionally to about 20-30%.
3) The pF-moisture content curves of these soils change remarkably. Namely, capillary water and gravitational water in these soils increase greatly by soaking.
4) The decrease of the shear strength by soaking is considered to be closely related to the change of the pF moisture property.