Difference in shear enhancement between beams and pile cap

[Eric Yip]

Dear all,

I would like to ask the difference in shear enhancement between beams and pile cap. For both elements, the enhancement factor is 2d/av. In beam design, av is measured from the face of the support. However in pile cap design, av is measured form the face of the concentrated load (column above) and the critical section is taken at 20% of the pile diameter inside the face of the pile. What I think is the pile being a support for the column above, why av is not calculated from the face of pile, instead from the face of the column above? Thanks.

 

[KootK]

What code are you using? Are you able to post the pertinent sections here?

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.