Retaining wall-drained or saturated

[WWTEng]

One design firm that I worked for had had a policy to design retaining walls for undrained/saturated condition, even if a drain was shown on the drawings. I was told that the reason behind that was the fact that the drain may get clogged and, with rain or high water table, the soil may be saturated.

Is this a common practice to simply ignore the drain?

 

[concretemasonry]

It all depends on the amount of control you have over the materials and placement of the drainage and backfill plus the piping installation.

Also, what confidence do you have over the landscape and grading?

It is a judgement call.

Dick

Engineer and international traveler interested in construction techniques, problems and proper design.

 

[hokie66]

I think it is common practice to ignore the drains. They almost always fail eventually.

 

[fcu45]

Ignoring the drain will be more conservative.

If you want to improve your drain and reduce the possibility of clogging, you may cover your perforated drain pipe with the modern Geotextile as there are types can be used for such purpose. You can find lots of details in this free book: 'Geosynthetic design and construction guidelines' from US department of transportation.