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The models were instrumented with accelerometers, pore pressure transducers, and displacement
transducers. The results are presented in Figure 5.4. The settlement at the crest of the
embankment is plotted as a function of the accumulated root mean square of the input
acceleration record. This method accounts for the intensity and duration of the input motions.
The relative effectiveness of the remedial methods is evident from Figure 5.4. Although the
ground treatment and structure mitigation techniques substantially reduced the resulting
embankment deformations, residual deformations were experienced.
Figure 5.4: Results of Model Testing of Embankments (Adalier et al. 1998)
These studies provide useful information for field applications. However, more work is needed
to before robust design guidelines can be produced. The soil improvement recommendations
provided by PHRI, though not deformation-based, provide an applicable method of estimating
the necessary extent of ground treatment based on advanced numerical and laboratory modeling.
Chapter 7 addresses methods for determining the extent of ground treatment required to
minimize permanent earthquake-induced deformations of embankments. The primary objective
of this work is the development of straightforward procedures for estimating the optimal volume
of soil improvement (by densification methods only) at bridge sites.
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