Retaining walls and Natural ground

[mgk13]

Does a retaining wall to engineers specs make landfill natural ground, or do I still have to sink my foundation into the original natural ground?

We are constructing against a slope and the north side is all filled up. It means that our foudnation should at least be 3 meters deep. A retaining wall on this side is also planned. Is it thus better to first construct the retaining wall and then dig normal foundations?

 

[Focht3]

I don't have a good mental picture of your site and layout. Please describe the layout again.

By "landfill", do you mean the material is trash - or soil that someone has moved? If "landfill" means trash, do not use it to support your wall. If "landfill" means man-made ground (and I suspect it does), then you may or may not be able to put your wall on top of the fill. You need to hire a local geotechnical consultant to answer that question.

Do you build the wall or foundation first? In general, you build the wall first so that your building site is protected from damaging soil movements. But you also need the advice of a local geotechnical consultant on this issue.