ABSTRACT
Due to the cubic geometry, the soil balls can distribute more homogeneously in the container, leading to a smaller scatter band. While at the cubic container the variation coefficient of n is vc = 0.005, it is vc = 0.019 at the prismatic container. 2.2 Inner friction angle
When recalculating the inner friction angle of the soilϕ by the measured horizontal forces on the front walls at the state earth pressure at rest, again, scattering inner friction angles occur (Figs. 1 & 2). These deviating inner friction angles are even encountered at the same front wall at the same pore content. At the prismatic container the mean inner friction angle ϕm is 26.7◦ with vc = 0.19, at the cubic container ϕm is with 32.2◦ generally higher, vc = 0.06. The less pronounced variation of the inner friction angle of the numerical soil in the cubic container is due to the enlarged front wall area in respect to the prismatic container. Thus, more balls can stress the front wall and the influence of each single ball is less distinct.This also explains the overall higher inner friction angles.
