How to simulate the rainfall for slope stability problem?

Hello,

I was trying to simulate this paper. I want to see the effect of rainfall on slope stability. I don't know where I am making mistake. I am describing step by step of my model.

Here is the original model in this paper (Effect of long duration rainstorm on
stability of Red-clay slopes)

At first, I wanted to try with SEEP/W analysis. I am facing some issues boundary conditions. At first, I defined water table through piezometer surface as above figure mentioned that point F,G water pressure zero where I drew the water table line like this:

Then I defined left and right side boundary as an impermeable. Also, I put the total head in left side as 10 m and right side as 2 m (same as water table line value for left and right point).

After this, I run the analysis with having water flux (6.25 mm/hr) value at the following picture.

But, I can match their results as they drew the pore water pressure at various locations. I am pretty much sure that I am doing some mistake in Boundary conditions. Can anybody help me in this regard?

I am also adding some photos for your understanding.

I believe that SIGMA/W will have the same Boundary conditions.