Seismic stability of earth dams and embankments

In the design of earth dams and embankments under earthquake loading conditions, displacements offer a better criterion than a factor of safety on shear strength. The displacement depends on shear strength, inertia forces and pore-pressures generated during the earthquake. The model of a rigid block on a plane surface is used to analyse the effect of inertia forces and pore-pressures on the stability of an earth dam or embankment during strong earth-quakes. The study is based on limit equilibrium principles and the material obeys the Mohr-Coulomb failure criterion with effective stresses. It is shown that by using the pore-pressure parameters A and B, the excess pore-pressures generated during an earthquake can be accounted for in the effective stress analysis. It is also shown that displacements during an earthquake can be easily calculated by using simple pulses. Several interesting conclusions are drawn and an example of application of the method to earth dams and embankments is given. Dans le calcul d...