Pile Movement Versus Movement 1

[Riggly]

Does anyone know of any literature that relates the blows per foot of a pile to it's capacity?


Thanks

 

[UcfSE]

"Foundation Engineering" by Braja Das has some equations that relate maximum rated hammer energy, efficiency, hammer type and number of inches per blow to pile capacity.

 

[SlideRuleEra]

The traditional Engineering News Formula does this. Here is an online calculator for Vulcan hammers

http://www.vulcanhammer.com/enr.php

Here is the Corps of Engineers "Design of Pile Foundations" for general information

http://www.usace.army.mil/inet/usace-docs/eng-manuals/em1110-2-2906/toc.htm

You may also want to look at the Corps of Engineers "Pile Driving Equipment" at the link given below:

http://www.SlideRuleEra.net

 

[BigH]

Use of dynamic formula for pile capacity - always a hot topic. I would refer anyone to the papers by Flaate back in the 1960s - he did very extensive study of lots of pile load tests and developed modified dynamic formulas. I found the use of the Gates formula to be straightforward and reasonable - have used it as a check of installation many times. Papers are in ASCE Foundation Journal (now Geotechnical Journal).

 

[DRC1]

Dynamic formulas have a dificult time capturing the true conditions of pile driving and consequently are a rough approximation at best. With the advent of computers, wave equation provides a much better answer and can be performed fairly quickly. I would strongly urge running a wave equation over a hammer formula.

 

[Riggly]

Thanks to everyone who have responded to this post. I appreciate you help.

 

[BigH]

DRC1 - you are right, of course, but... not everyone or every project will have a dynamic analyzer available.