Energy Approach to Earthquake-Induced Slope Failures and Its Implications

So far, earthquake-induced slope instability has been evaluated by force equilibrium of soil mass in engineering practice, which cannot evaluate failure deformation once large failure occurs. An energy approach is proposed here, in which the amount of earthquake energy is evaluated in conjunction with the gravitational potential energy dissipated in slope displacement including large flow deformations. Shake table tests of dry sand slopes are carried out in which the earthquake energy used for slope failure can be successfully quantified. Measured slope displacement can be reliably evaluated by the proposed energy approach based on a rigid block model if an appropriate friction coefficient of the slope is specified. The energy approach is then applied to hypothetical slopes, indicating that even if extremely large earthquake energy is considered, slope failures with long run-out distance will not occur unless friction coefficients reduce near to or smaller than slope inclinations.