Evaluating Seismic Stability of Embankment Dams - Multiscale Geomechanics: From Soil to Engineering Projects - page 373

Figure 10.14. (continued) Comparison between reconstituted in situ and calculated shear
bands for the 1971 earthquake (from top to bottom: shear strains <5%, shear strains
<20%, liquefaction factor, horizontal displacement and vertical settlement)
10.6.7.8. Justification of the stability of the upper embankment during the 1971
earthquake
The numerical results for the upper dam are different from those obtained for the
lower dam. First of all, the curves of 5% shear strain values are not continuous from
upstream to downstream. We obtain zones of strain concentration, but they are not
generalized from one side of the dam to the other. In reality, failure did not occur,
which is in agreement with the model prediction showing a non-continuous 5%
shear strain zone. The liquefaction factor reached only 50%, which indicates that the
liquefaction did not spread within the embankment base. The calculated
displacements remained small, reaching 0.75 m for the horizontal displacement due
to the sliding of the upstream and downstream facings, compared to the 2.20 m
displacement measured downstream. The calculated vertical settlement reached
0.70 m, in complete agreement with the measured value of 0.76 m. For this
embankment, the stability criteria were not exceeded, which is confirmed by its real
behavior during the earthquake (see Figure 10.15).