Two Columns On one pile cap 2

[Sam1993]

We are designing two building and we have two close columns in between so we are going to design these two columns on one pile cap with one pile
(2columns are 200 kips and 100 kips, clay soil, end bearing 4000 psi, skin friction ignored, Pile Diameter shaft is 3.3ft,bell is 10ft)

we can not make it two piles because the piles are drilled shaft bell diameter and the bells will conflict

If we designed two columns on one pile how about differential settlement between the two building would affect the pile cap?

 

[dik]

As long as you can accommodate the unbalanced loading, there should be no problem. It's not common. Is there a 'work around'? Just because you can do things, does't mean you should.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Do you feel any better?

-Dik

 

[SlideRuleEra]

Agree with dik, two loads on one pile is not a good idea. Design loads may be 200 kips and 100 kips, but what happens if (when) actual loading differs? Say, 200 kips and 70 kips?

 

[TigerGuy]

How about eliminating the bells and switching those to straight shafts? At 4,000 psf, your 200 kip column would require a shaft diameter of 8 feet, and the 100 kip column would require a shaft diameter of 6 feet. What is the spacing between the columns? If there is not room for the 2 shafts under the columns, I would increase the size of the cap and add another shaft or 2 to balance it all.

 

[le99]

Depending on the distance between the columns, I may consider two approaches: 1) enlarge the pile, and align the center of the pile with the center of the greatest gravity loads, and 2) provide two slightly inclined piles.