| Popis: |
The determination procedure of coefficient of friction μ for unsaturated sandy soil by a series of box shear tests is proposed in this paper. At first, it is assumed that slip surface is Spatially Mobilized Plane (SMP). And coefficient of friction μ is obtained from energy dissipation equation on SMP. That is, coefficient of friction μ is determined by the value of τ/σ when compressive displacement y reach to the maximum y_max ( i.e., maximum negative dilatancy). Here, σ and τ are normal stress and shear stress on SMP. Secondly, coefficients of friction μ for unsaturated Toyoura sand are obtained from a series of box shear test datum with different relative density. And relationship between coefficients of friction μ and degrees of saturation S_r are clarified. Finally, the value of critical state parameter M (capital μ) is calculated by relationship between M and μ in conventional triaxial compression test condition. |
