Foundation - Flexible or Rigid?
Foundation - Flexible or Rigid?
(OP)
Hi floks!
What defines the foundation to behave as a flexible or as a rigid?
Ive seen dozens of articles where people call foundations - flexible, semi-flexible, semi-stiff, stiff....and this applies to strip foundations, rafts....
Ive always thought of strip footing (under the wall), whoes 45 degree disperse load line doesnt pass thru the bootom, as a stiff foundation.
If I imagine this same strip footing placed under 3 columns (spaced few meters away and acting as 3 point loads) I would say that the foundation would behave a flexible since it will start bending.
But this "flexible term" would again depend on the b x h dimensions and the E modulus of the strip.
Looking the at the same strip with 3 point load, strip with a height of 1m would be considered stiff compared to a strip of a height =0.5m.
Loads should also be considered in this classification...
Thank you.
What defines the foundation to behave as a flexible or as a rigid?
Ive seen dozens of articles where people call foundations - flexible, semi-flexible, semi-stiff, stiff....and this applies to strip foundations, rafts....
Ive always thought of strip footing (under the wall), whoes 45 degree disperse load line doesnt pass thru the bootom, as a stiff foundation.
If I imagine this same strip footing placed under 3 columns (spaced few meters away and acting as 3 point loads) I would say that the foundation would behave a flexible since it will start bending.
But this "flexible term" would again depend on the b x h dimensions and the E modulus of the strip.
Looking the at the same strip with 3 point load, strip with a height of 1m would be considered stiff compared to a strip of a height =0.5m.
Loads should also be considered in this classification...
Thank you.





RE: Foundation - Flexible or Rigid?
Now I'm guessing that a decent computer program could analyze the in-between cases. But you still need soil stiffnesses which are not always provided by the Geotechnical Report.
RE: Foundation - Flexible or Rigid?
The following link has a spreadsheet that will calculate what you are asking.
http://www.steeltools.org/resources/viewdocument/?...
http://www.soilstructure.com/
RE: Foundation - Flexible or Rigid?
This is great!