Underground Column Design

[Ahmed A. Alamin]

Hello, a 3m short column " column that extends from the foundation up to the suspended floor level" was designed as such, the client whiches to elevate the ground floor up higher "1.2 m " due various reasons. The problem with that is that one particular column fails. When designing theses columns considering the new height no consideration for the surrounding soil from the foundation level up to the groubd level was made. I was wondering if threre is a way to consider such effect in hope that is to reduce columns effective length. Is this right?

 

[Lomarandil]

In a native soil... Maybe.

In backfill -- I would lean toward no.

----
just call me Lo.

 

[human909]

No, so much no.

Though like Lomarandil if it is completely surrounded by undisturbed natural soil then it could work but then it would likely be a pile not a column.

 

[jayrod12]

Are you compacting fill back underneath? We've had to specify compacted granular around stuff like this to maintain lateral stability. The geotech gave the compaction requirements.