Retaining Wall with Piles on slope

[pshirls]

I am new to designing retaining walls/piles. I am designing a house on a slope that has a retaining wall to hold up a proposed back yard. The retaining wall runs from 16' above grade to 24' above grade. It will be holding back a fill that will create a flat ground above. Beneath the retaining wall we will have a grade beam to tie the piles and retaining wall together. Can anyone recommend a good resource (either book or program) to help my calculations and general knowledge on the subject? The project is in Los Angeles, CA. Thanks!

 

[jdonville]

A 16- to 24-foot high wall is a major undertaking on a slope, as the slope at the toe will generally not provide the passive pressure required to restrain the movement of the fill soil.

Additionally, you will need to look at the deflection of the wall system due to the retained fill and the overall slope stability.

You indicate that you are a structural engineer, so my advice is to work with a geotechnical engineer who can provide recommendations for the wall design, including the type of wall (if feasible).

Again, this sounds expensive (the engineering fee is small potatoes compared to the construction costs), and your client may get some sticker shock.

Good luck!

Jeff

 

[MSEMan]

What are the soil conditions at the site? Depending on the materials you are founding the wall in you may find that an intermediate foundation system such as Geopiers is more economical - also you may not want to tie the wall system and the foundation supports together since this will drive up the cost of the foundation. Have you thought about putting an MSE wall on an intermediate foundation system?

 

[structuralaggie]

Yea, you need goetech help for sure. This sounds similar to a house I did in Houston. We created a sort of terrace that stepped up about a total 40' to the finish floor. Everything was structurally supported on slurry piers, some were 60' deep due to slope stability concerns. We used a combination of a cantilver retaining wall system and piers to retain the soil. The geotech told us the max. lateral loading we could have on them.