Tie/Grade Beam for Piled Foundation
Tie/Grade Beam for Piled Foundation
(OP)
Hello,
I am designing a piled building foundation for a metal building. Currently we have two piles under each column (aligned perpendicular to building wall), with pile caps and concrete piers. We are using a perimeter grade beam to tie the pile caps and piers together, and distribute column lateral reactions along the foundation line, as well as support the exterior building wall. See sketch of plan: Plan Layout
The question that I have is this: The grade beam is used to take the lateral reaction from the columns and provide stability for the foundation. Since the grade beam is smaller in width than the piers, the centreline of the grade beam does not coincide with the centreline of the piers/columns. Does this create a concern for the twisting of the piers when considering the load transfer from column to grade beam? Is this a good design layout? Is there something that is better for achieving the design intent?
Any comments would be appreciated :)
Thanks in advance.
I am designing a piled building foundation for a metal building. Currently we have two piles under each column (aligned perpendicular to building wall), with pile caps and concrete piers. We are using a perimeter grade beam to tie the pile caps and piers together, and distribute column lateral reactions along the foundation line, as well as support the exterior building wall. See sketch of plan: Plan Layout
The question that I have is this: The grade beam is used to take the lateral reaction from the columns and provide stability for the foundation. Since the grade beam is smaller in width than the piers, the centreline of the grade beam does not coincide with the centreline of the piers/columns. Does this create a concern for the twisting of the piers when considering the load transfer from column to grade beam? Is this a good design layout? Is there something that is better for achieving the design intent?
Any comments would be appreciated :)
Thanks in advance.






RE: Tie/Grade Beam for Piled Foundation
1) assume that the grade beams constitute lateral restraint at the top, exterior corners of the piers. Design the concentrated ties at the top of pier to be able to transfer the lateral load from the column back to the line of the grade beams.
2) work out the torque resulting from the pier / grade beam eccentricity and design the pier to transmit that torsion down to the pile cap.
Depending on how the slab on grade is detailed, you can sometimes make use of that too, at least in a belt and suspenders sense.
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.
RE: Tie/Grade Beam for Piled Foundation
RE: Tie/Grade Beam for Piled Foundation
RE: Tie/Grade Beam for Piled Foundation
Does anyone know of a good reference that addresses this issue or provides some design examples?
RE: Tie/Grade Beam for Piled Foundation
Kootk, nice stationary.
RE: Tie/Grade Beam for Piled Foundation
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.
RE: Tie/Grade Beam for Piled Foundation