Spring settings for pile buckling

[Anonymous]

Hi,

I'm trying to analyze a simple pile buckling case, with the soil represented by elastic springs.

To keep it simple I started in 2D frame analysis using a bar.

Lets say my soil stiffness is 500kN/m3 and the pile is 0.1m wide with 1m distance between nodes.

Should the spring constant then be 500*0,1*1 = 50 kN/m?

It gives me strange results, for example too long buckling length and too low buckling load.

So my question is how do I set the spring stiffness to represent the soil?

Thanks in advance!

[Simau · Accepted solution]

Hi @Anonymous 

Lets say my soil stiffness is 500kN/m3 and the pile is 0.1m wide with 1m distance between nodes.

Should the spring constant then be 500*0,1*1 = 50 kN/m?

Yes

It gives me strange results, for example too long buckling length and too low buckling load.

Could you be more precise, what results do you expect?

Could you send your model

So my question is how do I set the spring stiffness to represent the soil?

You may use your first method, or assign elastic ground to the pile

[Anonymous]

Simau concluded that the problems were due to incorrect spring stiffness. It should be 500 kN/m3 input instead of 50.

Thank you very much for your help Simau!

[yesterday55555]

For example : If you have this continue footing and Kz=500 kN/m3
That means you must set Kz in the box = 500*1.2 = 600KN/m2

You must set like this.