Soil stress visualization

[benairo]

Hello,

I'm trying to visualize the stress in the soil due to the action of a shallow foundation, but I only know how to see the stress in the bottom of the slab.
How can I see the soil stress?

Thank you.

 

[darkjmf1]

In the "Joint Reaction Forces" form (Display -> Show Forces/Stresses -> Joints) there is a check-box at the bottom labeled "Show Soil Pressure".
Hope that's what you are looking for.

 

[benairo]

Hi,

Thank you for your answer.
I don't have that option. Only appears "show results as arrows"
Please see the picture below:

Thank you

 

[darkjmf1]

I am with version 17 of SAP. I guess you are with an older version, which did not have this feature yet.

In "old times", we used to obtain soil bearing pressures just multiplying vertical displacements by ballast coefficient. Easy to do with Excel, starting from exported displacements.

If you want to have a graphical view, just plot the vertical displacements; they are directly proportional (by the mentioned ballast coefficient) to the bearing pressure.
To do so: Display -> Show Defomed Shape. In the "Deformed shape" window, check "Draw displacement contours on area objects" and select "Uz" component.
Although I do not know for sure if this feature was enabled in your version...

 

[benairo]

I'm with version 15. Maybe for that I don't have this feature.

I want a graphical view of the soil stress above the foundation in SAP2000. If I understood that is not possible with this version. Only plot of displacements and efforts on the slab?

Want do you mean by ballast coefficient?

Thank you for your time.

 

[darkjmf1]

With ballast coefficient I meant modulus of subgrade reaction (Ks), typically expressed in KN/m3 units.
Please refer to

http://www.eng-tips.com/viewthread.cfm?qid=27153

Soil pressure (KN/m2) = Vertical displacement (m) x Modulus of subgrade reaction (KN/m3)

 

[benairo]

Thank you