Lateral Earth Pressure

[Sally_Ameen]

Hi Everyone,

I am trying to model lateral earth pressure from a user defined soil (Phi 23 degree, Density 1800). But, when I apply the load the pressure will become double on my model.

with hand calculation I expect 31.7 KN/m2 but robot shows 63.41 (exactly double amount!!).

Attached is my model and appreciate your support to let me know if I modeled anything incorrectly.

Thank you in advance..

[Krzysztof_Wasik]

Hi @Sally_Ameen 

This value describes contour load in one of 3 points determined for defined geometry and soil layers.

In that case value corresponds to pressure on level in point C  (z=-4.1 m)

Since model height is 4.1 applied load should be correct.

[Sally_Ameen]

Thank you Krzysztof. As a resultant point load I expect  ~ 63.41  KN per meter run ( 0.5 x lateral soil pressure x structure height = 0.5x31.7x4.1) but robot calculates 63.41 KN/m2 which translates to resultant point load of 0.5*63.41*4.1=129.97 KN per meter run

[Sally_Ameen]

This my hand calculation

[Krzysztof_Wasik · Accepted solution]

Hi @Sally_Ameen 

Results are correct. In contour load definition pressure 65 applied on level -4.1 correspond to pressure 32 applied at level 0

While pressure load application program describes pressure below wall bottom level.

In your case total horizontal reaction is 65 kN as expected.

[Sally_Ameen]

Thank you so much it is clear now. But, honestly it is over complicated 😁 why the "soil pressure model" generates a load at Z=-4.1 while my structure height is in the positive Z direction.

Is there any way to avoid generating earth pressure at negative Z direction?

[Krzysztof_Wasik]

Hi @Sally_Ameen 

No. You cannot modify this automatic procedure. You can correct generated load manually (as on screenshots from my previous emai) to obtain required load description. Regardless that load is applied to the structure correctly.