Dear Engineers,
Is it possible to create +Fy restraint support in STAAD?
When I use
FIXED BUT FX FZ MX MY MZ
It restraint in both +Fy and -Fy
My condition is simple rest support. Only +Fy restraint and -Fy is free
Is it possible to create such a support in STAAD?
You can appropriately use the Tension / Compression only springs in the FY direction as shown in the attached input file as an example.
FYSpring.std
Answer Verified By: vivekshine
Yes, It is possible to create +Fy restrain Support in Staad.Pro.
You can assign this kind of support (+Fy restrain Support) as a Compression Only Spring.
I have attached a sample where I have assigned a Compression Only Spring at node 1. So the support at that node will remain only when the reaction is +ve and will deactivated for (–ve) negative reactions.
Hope this helps you.
Spring Compression Example.std
RAJAT
Thanks a lot Mr.Amitava & Mr.Rajat It works. On What basis you assigning the spring constant value KFY? How did you arrived that value?
-Vivek
The stiffness of that spring depends on the soil strata. If it is hard rock, the spring constant will be a high value. Soft soils like clay will have a smaller constant. That spring constant is usually obtained by multiplying the area of the footing by the subgrade modulus of soil.
Spring Rigidity = (area of footing) x (sub-grade modulus of soil)