PDA (Case Method)
PDA (Case Method)
(OP)
Why is the resultant divided 2(R/2)when the downward compression way meets the shaft friction? Why is it not some other ratio which would be dependent on the value of the upward friction?
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS Come Join Us!Are you an
Engineering professional? Join Eng-Tips Forums!
*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail. Posting GuidelinesJobs |
|
RE: PDA (Case Method)
RE: PDA (Case Method)
one thing to point out is that you can have higher tension forces say if you have hard driving passing through a hard layer in to a very soft layer. you could also have high stresses for hard toe conditions. i believe the theory says you could approach 2x the input at the toe for the hard toe condition with no/minimal side friction.
RE: PDA (Case Method)
Conversely, for a free toe, you reflect a tension wave, which is why tension cracking has to be monitored during the early stages of pile driving for concrete piles.
A quick program which is good to illustrate this and many other aspects of wave propagation is the Pilewave program, which can be downloaded from
http://www.piletest.com
http://www.vulcanhammer.net
http://www.vulcanhammer.info
RE: PDA (Case Method)
Fix end - compression 2x top force
Free end- high tension
Infinit pile-no return wave
RE: PDA (Case Method)
RE: PDA (Case Method)
http://www.vulcanhammer.info/drivability/isa.php
In practical applications, the numerical solutions are necessary.
http://www.vulcanhammer.net
http://www.vulcanhammer.info
RE: PDA (Case Method)
RE: PDA (Case Method)
RE: PDA (Case Method)
http://www.vulcanhammer.info/drivability/
That includes the FHWA manual on driven piles, which is a good starting reference.
http://www.vulcanhammer.net
http://www.vulcanhammer.info
RE: PDA (Case Method)
RE: PDA (Case Method)
RE: PDA (Case Method)
RE: PDA (Case Method)
RE: PDA (Case Method)