Etabs area spring
Etabs area spring
(OP)
Hello mates,
Please i want to perform a soil structure interaction in etabs 2013. I have assigned area spring of 60000KN/M2/M, in the 3 direction, is my definition correct. I was confused if the modulus of subgrade needs to be negative.
I also want to know how to place a restraints in the x and y direction of the raft.
Thank you.
Please i want to perform a soil structure interaction in etabs 2013. I have assigned area spring of 60000KN/M2/M, in the 3 direction, is my definition correct. I was confused if the modulus of subgrade needs to be negative.
I also want to know how to place a restraints in the x and y direction of the raft.
Thank you.





RE: Etabs area spring
RE: Etabs area spring
Indeed it is important when considering uplift on base slab to ensure that the "soil" is not going into tension. So why is it, that when I model my basement structure (held in place with tension piles) and tick the non linear "compression only" box for an area spring I seem to get the soil giving tension reactions?
Any ideas?
Regards,
J5
RE: Etabs area spring
RE: Etabs area spring
@avecillasjavier, please what value should be used for the restraint in the X and Y direction. What I did was to select the nodes of the raft and assign only UX AND UY. What about that?
Regards.
RE: Etabs area spring
One thing to watch for is if you have an uplift case (fluid pressure uplift) you may want to watch your load patterns/cases. What was happening in my building is in the Hydrostatic case i had no moments because it wanted to lift up the building and there was no resistance since it only looked at that load case.