Foundation Design-Where to Start?


Enclosed is a project I would like to discuss about.

I am a little perplexed here, so any recommendations would be appreciated, e.g., where to start, what references are available, alternate approaches, etc.


Here it is (Couldn't upload it in the forum):

Thanks in advance,




Soil Mechanics / Geotechnical Design Analysis Construction Education Shallow Foundations Geotechnical Investigations & In-Situ Testing Deep Excavation & Retaining Walls Landslides - Slope Stability Deep Foundations

Asked 18/10/2013 18:31, updated: 14/03/2017 14:08
Ben Kingsley

1 Answer

Votes: 1

Gabrielle Rigaud

Hi Ben. I can see this was posted a while ago and you didn't get an answer. I've been out of school a while and working in geo-environmental more than geotechnical, not by choice. So I've been doing some soul/career-searching and decided to try breaking into geotech design. I came across your question because I was looking for exercises for myself. It's unfortunate that no one answer. But anyway... right off the bat, I have some questions. So I would say that you would need to have a session with your professor/client first. Architects are very particular. You could easily come up with a design that totally doesnt' suit their vision. 

The first thing is that first layer of soil. Hauling soil off-site costs money but at the same time, they might want unobstructed view from all sides. I wouldn't assume that they want it to say or go, especially that it's a LEED-certified building. They might have designed it to retain as much of the topography as possible. I'd ask.

The second thing I'd ask is floor heights and how much of the lower level is submerged. That will go into your cost estimate calculations. It might be worthwhile to keep the building above ground and collapse the slope around it or dig down to put the lower level etc... You should know what your options are. Remember that with LEED, the more stays on-site, the better and more sustainable. 

Then you have to worry about those faults in the soil layer. You want to know more about the nature of these faults. 

There's also the water table. You want to ask about water level history in the area. The water table is only 9' below ground surface. I'd want to know if it's been higher.

Anyway... to someone who does this every day, maybe these are not the right questions to ask but I'd personally want to know. And then start your bearing capacity analysis for the layers of material that you are given. You want to use the proper calculations for each layer type. It looks like you're dealing with sands and clay, or maybe till and clay. You want to consider the loads that you are given as well for the columns and determine whether you want to float this building or install drilled/driven elements of some sort.