Retaining Wall for Agricultural Building

[BayPointArchitect]

I am dealing with someone who wants to build a large storage barn into a hill side but they do not want to excavate and backfill along the entire length of wall. And that excavation would otherwise be necessary for the cast-in-place concrete heal (spread footing). And basic engineering would require a very wide spread footing to resist overturning. Note also within the attached sketch that there is no concrete slab on the inside of the wall.

I originally thought that I could provide dead men to resist overturning but that's not working for me with what I have so far.

What then would be a good alternative to the five foot wide spread footing?

Retaining wall illustration:

https://www.dropbox.com/s/9xvc3a0ylr9eq1k/Question%20for%20Jim.pdf?m

Thanks

ICC Certified Plan Reviewer

 

[Frank]

Sheet pile wall placed and anchors drilled into the hillside to retain as excavated--depth and type of anchor depends on type of soils encountered-- similar to marina constrction--drive piles anchor back to earth at the top. These are also used for shoring deep excavations.

 

[Mark K]

You do not need a heal if the toe of the retaining wall is long enough and there is enough dead weight. Drilled piers could also work. In any case they need to hire an engineer.

The deadman shown in the sketch is really a butress and is not an efficient way to go. A smaller heal and larger toe without the butress would be more economical and cut down on the amount of excavation.

Contrary to the sketch the centroid of the "deadman" is not 5 feet from the face of the wall. Do not see calculations showing the impact of overturning forces on the soil. Submission to be rejectedl An engineer should be retained.

 

[Phil]

I'll second Mark's recommendation for an engineer. Just because the calculations are pretty does not mean thay are right. It looks like there are two sets of calculations with different assumption. I don't think either overturning moment calc includes the wind load from the building and the soil bearing pressure does not include the overturning forces from the foundation. Without an interior slab, the retaining wall can have problems with sliding. Also, it is common to use the weight of the soil (approximately 100pcf versus 150pcf for conc) on the heel instead of adding a mass of concrete. But, then the footing needs to designed for bending.

 

[ICE]

Let me be Frank, I think that you aught to trust a guy named Phil when it come to holding back dirt. The other guy hit the Mark too.