A probabilistic finite element analysis of embankment stability under transient seepage conditions

Flood protection structures lend themselves to probabilistic design given the large uncertain variables. Taking into account the historical discharge statistics of rivers, the annual probability of failure by slope instability of an embankment along the river Elbe in Eastern Germany is determined using a finite element analysis. The effect of transient seepage within the embankment and its effect on embankment stability are considered. Whereas a steady-state seepage line is most critical for the embankment stability, a transient seepage calculation including the rise and drop of the river water level reveals stability reserves. It has been demonstrated that the First-Order Reliability Method with Adaptive Response Surface is an efficient calculation technique for coupling numerical simulations to a reliability analysis.