Effective base plate area for a PFC section

[nj86]

Morning guys,

I'm trying to calculate the effective area of a base plate for a PFC section (equal flange channel) sitting on a rectangular/square steel base plate but I'm not sure how to calculate the 'C' value.

I'm using British Standards: BS5950-1 clause 4.13.2.1

I have seen ways to work out the 'C' value with I and H sections but not sure PFC sections.

Any ideas?

Thanks!

 

[ishvaaag]

If you don't find solution and don't want (or musn't) use FEM investigation of the case, you (maybe) can close the C at bottom with a (stiffener-beam) rectangular plate to conform a rectangular line of contact.

 

[patswfc]

Its the same as how you calc it for any other type of section.
Assuming only axial load in the PFC then,

effective area of base plate = compression load / (0.6*fcu), where fcu is strength of concrete below base plate.

effective area is approx. equal to length of PFC section (depth of PFC + 2*flange width) * (2c + t)

Rearrange to find C.

 

[BAretired]

Exercising reasonable engineering judgment would seem to be the key to this dilemma. If in doubt, beef it up a bit.

BA