modelling cut off wall using plaxis 2d
I am having difficulties modeling the seepage in an earth dam enhanced with a cut off wall using Plaxis 2D. The cut off wall is made of plastic concrete and was introduced later as part of a maintenance procedure in order to prevent any potential leakage from the resevoir. The plastic concrete was defined using the soft soil creep model as a drained impermeable material. Tutorials nr.12 and nr.14 in addition to a webinar on running a groundwater analysis gave an overview of the GWF BC's and of how to use time dependent flow functions in a fully coupled flow deformation analysis and how to run a GWF analysis. I've tried to combine all these tutorials by the modeling process to obtain the most optimum seepage / flow line but still haven't succeeded. The results of the analysis show that the cut off wall doesn't influence the seepage, which indicates an error in the input data or in the definiiton of the GWF BC's.
Could anyone please help me solving this problem.
Thank you all in advance.