What bearing factors to use?

[maximus808]

To find the ultimate bearing capacity of a shallow footing, is it safe to use the bearing factors from the fe reference handbook for the general bearing factors. When I checked it with Terzaghi factors from Das Geo blue

Book it differs. The main factor that changes is Nq. I don't know why? So my question is if it does not mention terzaghi or meyorhof, what factors should I use. The general case or terzaghi case? Thanks

 

[Badger]

To find the ultimate bearing capacity of a shallow footing, is it safe to use the bearing factors from the fe reference handbook for the general bearing factors. When I checked it with Terzaghi factors from Das Geo blueBook it differs. The main factor that changes is Nq. I don't know why? So my question is if it does not mention terzaghi or meyorhof, what factors should I use. The general case or terzaghi case? Thanks

If they don't specify which ones, I would default to the table in the CERM, I think it is Meyerhof ones.

More than likely they will give you the values.

I think there was a another thread about this, and it suggested that when in doubt use the method in the CERM.

If you look at the afternoon geotechnical question #516 in the NCEES 2008 sample exam it gives an abreviated table.

The NCEES folks couldn't agree on which shape and depth factors to use and changed from a square footing to a strip footing so they didn't need shape and depth factors.

So i hope they specify which one or give you the bearing capacity factors.

 

[maximus808]

Thanks! I like the All in One's equations for bearing capacity too. Yes, the book was only about $50 fornmw but I use it for almost every practice problem I do now. My Cerm will be my back up tool

If I can't find what I need in the all in one.

 

[pmblair]

I noticed that there was a problem in the NCEES that used the same factors as the CERM, but..... I think as they did in that problem.... they will give you the factors in a table based on angles or something similar.