Interference between closely spaced shallow foundation embedded at different depths

[killswitchengage]

Hi
I know i shouldn't be asking this stupid question but what are the risks associated with closely spaced shallow foundations embedded at different depths ( One higher than the other by about 40 cm ).

thank you

 

[TigerGuy]

How close are they to each other? What size are they individually? What are the foundation loads?

If the loads are high enough and the foundations close enough, you could see some uneven settlement within the individual elements.

 

[killswitchengage]

Differential settlement is an issue obviously but I was thinking of lateral stresses on the lowest foundation imparted from the higher one, meaning the soil flows laterally against the lowest footing.

 

[EireChch]

This is only an issue if the foundations are closer than approx 40cm, which I doubth they would be , and if they are it would possibly make more sense to construct it as one foundation.

Agree that size and loading is a factor to consider. If small and lightly loaded then not an issue if wide, with high loading, supporting critical/sensitive infrastructure then may need an assessment