Posted Wed, 26 Mar 2008 17:50:15 GMT by Claudia Martínez Geologist Consultant (Hydrogeology)
I need to simulate a sub-horizontal tunel excavation to evaluate the impact in groundwater system. I used head boundary condition and restricion with max flux =0. It works for steady contidion or to see the impact after the tunel excavation but to see the impact during the excavation, it doesn't work. I used Time-varing power funcion to asign different head in different time, but the deepest nodes which should start to drain after one year, the boundary condition starts to drain at the begining of the simulation. also I made a function for restricion but it is the same, it start at the begining. How i can set this excavation. I'am using version 5.0.

thanks
Claudia
PD. please sorry my Espanglish writing.
Posted Wed, 02 Apr 2008 21:44:08 GMT by mnovotny
Claudia,
I don't understand your situation very well.  Perhaps you should attach a figure...

First, check to make sure your simulation 'initial time' is correct under the 'temporal and control data' dialog.  It is possible that you could be starting a simulation at time greater than you are expecting, which might explain why neither bc or restriction controls worked.







Posted Fri, 04 Apr 2008 16:00:57 GMT by Carolina Vera
Hi, it’s me again. I change my user because my password doesn’t work and I didn’t receive the mail for pass changing.

No, it was not a problem with the simulation time. It was the time-varying function setting.

I made a really simplistic example. I used a three layers model and use the middle slice to simulate the geometry of the ramp. It has approximately 150m of depth and 1,5 km of length. I set only six nodes with fix head BC and max flux = 0 restriction to represent the ramp excavation which takes 1 year then I set one time –varying function for each node. Until this stage is the same model that I did before. The difference is that I started the time-varying function every 60 days without set any value for first 59 days. (See below). Then (I think) FEFLOW used the first data (60 days) at first simulation days anyway.  If I set the ground elevation plus the seepage restriction (max flux =0) nothing happened with this node until day 60.1 when the elevation changes.  Well, now It’s working. I put this if someone has the same problem.


[b]Before[/b]
Time (day) F
60 361.67 (ramp elevation)
365 361.67



[b]NOW[/b]
Time (day) F
0 400 (ground elevation)
60 400
60.1 361.67 (ramp elevation)
365 361.67


Saludos
Claudia Martínez

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