Shaking Table Tests of Embankment Models Reinforced with Geotextiles - Reinforced Soil Engineering: Advances in Research and Practice - page 401

Figure 31 Damage to an earth dam caused by liquefaction.

damage to this dam, which was completely destroyed, in the central area. Boring
surveys conducted after the earthquake suggested that since both body of the dam
and its foundation were mainly composed of fine sand with an N-value of less
than 5, the damage was caused by liquefaction (Fig. 31). To make a comparison
with geogrid reinforcement and to confirm the reinforcement effects in a model
experiment of foundation improvement, find sand similar to that used in the
actual dam was used to construct a 1:10 scale model, which was then subject to
shaking table tests. The model dam was divided into two models of 4.5 m in
length, 2.8 m in width and were simultaneously subjected to seismic vibration.
Test were conducted for the following cases:

C1-1: Nonreinforced embankment.
C1-2: The foundation of the embankment was improved with cement-type
materials.
C1-3: The embankment was reinforced with geogrids.

Diagrams of each of three cases are shown in Fig. 32 .
The sand used in the model experiment had a particle size distribution that
was almost exactly the same as the fine sand that was the main component of the
body and foundation of the destroyed earth dam. Specifications were sand content
of 94%, uniformity coefficient of 2.5, maximum particle diameter of 4.75mm,
e min ¼

0.627, and e max ¼ 0.957. The relative density of each model was

approximately Dr ¼ 60%. The foundation was improved with cement-type