Application of Fuzzy Set Theory to Evaluate the Effect of Pore Pressure Build-Up on the Seismic Stability of Karkheh Dam, Iran

Abstract

It is a current practice to employ composite clay—a mixture of clay and aggregates that float within the clayey matrix—as the core of embankment dams that have classically been constructed from pure clays. Experience has shown that significant pore pressures could build up during cyclic undrained loading in composite clays. This may threaten dam stability during earthquake loading. However, it is difficult to attribute a single value to excess pore pressure in conventional seismic stability analysis because of the random nature of earthquake loading, leading to uncertainty in the evaluation of factor of safety against sliding. This article evaluates the importance of pore pressure build-up in composite clays on the seismic behavior of Karkheh embankment dam in Iran and then documents a quantitative scheme using fuzzy set analysis to evaluate the failure potential of the dam.