Shaking Table Tests of Embankment Models Reinforced with Geotextiles - Reinforced Soil Engineering: Advances in Research and Practice - page 402

Figure 32 Earth dam model 2.

materials, and, considering that this was a model experiment, these materials
were added at a rate of 60 kg/m 3 , and the unconfined compression strength of the
samples was qu 500-700 kgf/cm 2 . It was difficult to improve the foundations

in the earth dam model, so the improved section was constructed separately and
incorporated into the model. Loading in each case was conducted for 7 sec under
sin wave and 3-Hz conditions. The maximum input acceleration was targeted as
stepwise loads of 100, 200, 300, and 400 gal. Pore water pressure, acceleration,
and displacement were measured.

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4.2.2 Experimental Results

The states of deformation at 300 gal for C1-1, C1-2, and C1-3 are shown in Figs.
33, 34 , and 35 , respectively. Massive deformation occurred in the foundation and
embankment of the unreinforced C1-1, but there was almost none in the
embankment of C1-2, whose foundation had been improved. Deformation in
C1-3 was about the same as that in C1-1, but many cracks appeared on the surface
of the C1-1 embankment, while almost no cracking occurred on the C1-3
embankment, which showed a generally “smooth” deformation.
As acceleration increased in the geogrid-reinforced model, more of the
acceleration was transferred to the upper section than in the unreinforced model,
so it appears likely that geogrids did little to reduce settlement. Figure 35 shows
total settlement of the crests of C1-1, 2, and 3 after vibration. Here we can see that
there was almost no settlement in C1-3, whose foundation had been improved.

Figure 33 Displacement of earth dam model 1 (C1-1, 300 gal).