Abstract
Unconfined flow is considered to be a crucial issue in geotechnical engineering and a challenge, to identify how the uncertainties of the soil parameters propagate to the output quantities of the problem. In the current paper, a new algorithm of stochastic finite element method using generalized polynomial chaos is presented as a method to propagate the permeability’s uncertainty to the output pore pressure results. A numerical example of unconfined flow with rainfall has been solved for various level of uncertainty and for different boundaries conditions and the results compared with those obtained by random finite element method which is treated as the exact solution.