Pile ôFixed Head Conditionö
Pile ôFixed Head Conditionö
(OP)
There have been some discussions on this topic. What I wonder is the detail to be entitled as “Fixed Head”.
In my impression, it is generally required to have at least 12” pile embedment into concrete, and some reinforcement is also required in the 12” thick concrete. The main reinforcement is still above pile cut-off. But some engineer advises that the main reinforcement of the pile cap should be placed near the bottom of concrete to make it really “fixed”. This sound a bit odd to me, not only the rebar can not go through the piles, also the Strut-&-Tie model (for vertical load) will be off the “hook” with this detail.
This is a pile cap with two steel pipe piles and cap plates, plus strong anchor rods from plates into concrete.
What do you think?
In my impression, it is generally required to have at least 12” pile embedment into concrete, and some reinforcement is also required in the 12” thick concrete. The main reinforcement is still above pile cut-off. But some engineer advises that the main reinforcement of the pile cap should be placed near the bottom of concrete to make it really “fixed”. This sound a bit odd to me, not only the rebar can not go through the piles, also the Strut-&-Tie model (for vertical load) will be off the “hook” with this detail.
This is a pile cap with two steel pipe piles and cap plates, plus strong anchor rods from plates into concrete.
What do you think?






RE: Pile ôFixed Head Conditionö
RE: Pile ôFixed Head Conditionö
RE: Pile ôFixed Head Conditionö
In additional to the stiffness of the cap, fixty of the connection between pile and pilecap is another important measure to make the "Fixed-Head Condition".
I believe 12" embedment is conventional for "Fixed-Head", but I'm not sure what reinforcement detail in the 12" concrete is more practical. I remember some statement from Joseph Bowles' foundation design book, but I couldn't find it now.
prsconsultant, you're right, lateral stiffness (or allowable lateral load) is typically the business of geotechnical consultants. They advice the pile lateral load stiffness of "Free-Headed" piles and "Fixed-Headeded" piles. What I'm talking is about how to make the connection (or interface) fixed.
RE: Pile ôFixed Head Conditionö
Mike McCann
McCann Engineering
RE: Pile ôFixed Head Conditionö