Meyerhoff vs Th. of Elasticity Settlement

[RJ62]

I have a soil profile consisting of 3 ft of ML followed by SM to a depth of 20 ft. The SPT counts are:
Depth (ft) N (corrected)
1 16
3.5 15
6 9
8.5 10
13.5 6
18.5 5

The estimated settlement using Theory of Elasticity (Timoshenko & Goodier, 1951) as presented in Bowles,1996 is 1.2 inches. Meyerhoff gives 0.6 inch.

Load is 75 kips, 5' X 5' footing, embedment 1.5'.

I believe Meyerhoff settlement is based on SAND. What's the opinion of the validity of Meyerhoff? And if valid, is it also valid for silt and clay? I've seen it used for clay settlement estimates. And why the big discrepency with Th. of Elasticity?

Jefferys

 

[Focht3]

Personally, roughly [½] inch "discrepancy" in settlement calculations from two different methods isn't cause for consternation - it's cause for celebration!

Theory of elasticity applies to both sands and clays; the key is picking the modulus of elasticity. That's easier said than done - a factor of two difference in selected values is actually quite common.

I can't remember whether Meyerhof's method addressed clay, sand or both. Have you looked up his original paper? What did it say?



Please see FAQ731-376 for great suggestions on how to make the best use of Eng-Tips Fora. See faq158-922 for recommendations regarding the question, "How Do You Evaluate Fill Settlement Beneath Structures?"

 

[cbosy]

Meyerhoff I believe is only for sand. We use it for the sands around the Great Lakes and it seems to work well.