Probabilistic evaluation of seismically induced permanent deformation of slopes

A probabilistic approach that can systematically model various sources of uncertainty involved in the assessment of seismically induced permanent deformations of slopes is presented. This approach incorporates probabilistic concepts into the classical-limit equilibrium and Newmark-type deformation analysis and the risk of damage is then computed by Monte Carlo simulations. The spatial variability of the material properties and the uncertainty arising from insufficient information are treated in the framework of random fields. The uncertainty of seismic loading is modeled by generating a large series of hazard-compatible artificial motions. This approach provides a consistent level of risk within the time period of interest. The results of the case analyses show that the uncertainty of the soil properties can have a significant impact on the computed risk of failure for a slope with spatially correlated soil properties exposed to relatively low levels of seismic hazard (RMS<0.1–0.2 g); however, it appears to have little impact on the computed risk if the slope is exposed to relatively high hazard levels (RMS>0.1–0.2 g).

► We present a probabilistic approach to seismic deformations of slopes. ► The uncertainty of loading is modeled by a number of hazard-compatible motions. ► The results indicate that the earthquake hazard is the more critical factor. ► A moderate variability in soil properties has a small effect on the risk.