Evaluating Seismic Stability of Embankment Dams - Multiscale Geomechanics: From Soil to Engineering Projects - page 379

100

80

Rupture (2%)

60

Rupture (5%)

40

Rupture (2%)

Rupture (5%)

20

0

0 0 , 5 1
m a x im u m a c celeration atthesurfaceAmax(g)

maximum acceleration at the surface PGA (g)

Figure 10.20. Joint influence of the relative density Dr
and of the maximum acceleration PGA

The criteria adopted for characterizing the failure of the embankment are the
following:

− shear strain >2% along a sliding surface upstream-downstream or downstream-
upstream;

− maximum shear strain >5% in a zone within the embankment.

The conclusions of this study are:

− with Dr around 30%, the strongest earthquake acceptable has a PGA = 0.2g;

− with Dr around 50%, the strongest earthquake acceptable has a PGA = 0.5g;

− with Dr around 80%, the strongest earthquake acceptable has a PGA = 0.8g.

The model justification based on real failure and numerical study appears to be
quite satisfactory. An improvement in the robustness of the numerical method
remains to be achieved for assuring the model qualification.

10.7. Bibliography

[AFP 07] AFPS, Groupe de Travail Zonage 2005-2007, Résolution du Conseil, Avis du CST
et Rapport, Paris, 2007.