Centrifuge Modeling of Seismic Performance of Reinforced Earth Structures - Reinforced Soil Engineering: Advances in Research and Practice - page 408

2 CENTRIFUGE IN STUDY OF EARTH REINFORCEMENT

2.1 Principles of Centrifuge Modeling

The behavior of soil structure highly depends on its stress conditions (s,t), which
are mainly caused by the self-weight of the soil. For example, the strength of soil
t f and the shear stress t on a possible slip plane in a slope are functions of the
normal stress s.

t f ¼ c þ stanf ð 1 Þ

t ¼ f ð H ; b ; g ; etc :Þ ð 2 Þ

where c and f are the cohesion and internal friction angle, respectively, and
H, b, and g are the slope height, angle, and unit weight of soil as shown in
Fig. 1.
The behavior of the slope depends on the mobilized strength or factor of
safety defined by the following equation:

t f
t

F s ¼ ð 3 Þ

Therefore, this nondimensional number (F S ) should be properly represented in a
model in order to simulate the prototype behavior in it. However, confining
stresses (or overburden pressures) as well as shear stresses of soil in a small-scale
model under the ordinary gravity field (1 g) are very small compared with its
prototype, which causes an erroneous behavior between the model and the
prototype.
Provided that the soil in a 1/N-scale model has the same properties as
that in the prototype, which means c m ¼

c p , f m ¼ f p , and g m ¼ g p , the safety

Figure 1 Slope and possible failure surface.