Meyerhof Point Bearing Capacity - The Limiting Factor

[T2ioTD]

I am troubled with the so called Meyerhof limiting factor for the point bearing capacity, which always seems to be much lower than the formula it intends to control, up to making the main formula completely obsolete- either this, or I miss something completely.
First, some extract from Braja book:

Then, I did the calculations using Excel for different values of Phi', and in all cases, there is that huge gap between the 2 formulas:

Any thought?[highlight #FCE94F][/highlight]

 

[Smoulder]

I think meyerhof is outdated. I remember the name but haven't used in decades. I seem to recall the same. Meyerhof was spec'd by client's engineer on a job which needed really deep piles. The maximum limit governed after about 10m and it wasn't even close to the other equations. Meyhof has really high Nq numbers if I remember right and the max limit is needed to get something reasonable. Change your numbers to Mpa and you'll probably be happier. For 40 degrees you're at 76Mpa without the limit. Better than rock which isn't right.

 

[DanielSgeo]

The Meyerhoff method is still around I the AASHTO world, but it’s a different formulation than what you’ve shown above. It’s based on SPT blow count directly. I’ll post some screen shots tomorrow when I’m back in the office.