horizontal thrust

[rittz]

what have you found to be the acceptable max thrust resistance of 16" dia cast in place pile say 20ft deep for a foundation for a rigid frame building so to avoid the necessity of thrust rods or clothes pns, or battered piles

 

[rittz]

We fully expect sone heaving in the floor slab-on-grade (highly plastic clay) so the slab should be independent of the grade beam

 

[rowingengineer]

Don’t know what i have found to be an acceptable max thrust, but I have used piers of about that size to take the base reaction for wind loads, without connections to the floor slab.

An expert is a man who has made all the mistakes which can be made in a very narrow field

 

[rscassar]

I may be ignorant here, but can you please elaborate on a thrust rod or clothes pns?

Are you referring to the lateral resistance of piles?

I have typically found the lateral resistance of piles to be governed by the soil conditions before the structural failure of the CIP pile. Where it has been critical for the pile to resist horizontal thrust (such as piles for large signs), I have requested the geotechnical engineer to perform a borehole and provide the undrained shear strength of the soil. From this, I have been able to calculate the embedment depths required for a particular lateral thrust based on the method of Brom's for laterally loaded piles.

When it comes to construction, I request the geotechnical engineer to confirm the minimum end bearing capacity, minimum shaft adhesion, minimum socket length into whatever material and a minimum undrained shear strength of soil.

This is referred to as 'Brom's method' and a good textbook which covers the topic is 'The Foundation Engineering Handbook' by Guraratne.

*CIP=cast-in-place