Pile Cap Design - Tensile Forces

[chaechaeng]

Hi, I have a question, according to Reynolds' Handbook, there are two equations for determining tensile force: one that takes the column size into account and another that does not. I assumed that column size is considered when dealing with larger columns.

Are there any general guidelines or rules of thumb for deciding when to factor in the column size? Would a 400mm column be classified as a large column in this context?

 

[driftLimiter]

I plotted out a range of values for dimension 'a' for the 2 pile group case to compare graphically how these two values are different.
You could do the same for other cases. I figure if the column 'half width dimension, a' is greater than 10% of 'l' you get notably less tension.

 

[driftLimiter]

Since 'ignoring the column size' is not really a real scenario. It should always be safe to include column size here, the idea of ignoring the column size is to get an upper bound, or conservative answer.