Tank Lateral Restaints
Tank Lateral Restaints
(OP)
Hello,
I was wondering if I could an opinion on this subject.
We are installing a plastic flat bottom tank in a building in a high seismic zone (BC Canada, west coast) and the question of required anchorage/restraint has come up. The tanks are such that both the overturning (empty and full) and sliding (empty and full) can be resisted by the self weight of the tanks alone.
There is a clause in the BC building code 2012 (4.1.8.18 8)) that stipulates that seismic forces cannot be resisted using friction loads and furthermore the structural commentaries specifically references the possibility of tanks "walking" under a seismic event.
My question is - would it be acceptable to provide lateral restraints at the bottom of the tank (i.e. angles bearing against the side of the tank) to prevent any lateral movement associated with sliding instead of anchors connected to the tank and foundation? I'm curious because the code is a little vague since it alludes to not using friction to resist sliding, yet it talks about walking which implies vertical movement. However the vertical movement is resisted by the self weight of the tanks which appears to be permissible by the code. Thoughts?
Thanks!
I was wondering if I could an opinion on this subject.
We are installing a plastic flat bottom tank in a building in a high seismic zone (BC Canada, west coast) and the question of required anchorage/restraint has come up. The tanks are such that both the overturning (empty and full) and sliding (empty and full) can be resisted by the self weight of the tanks alone.
There is a clause in the BC building code 2012 (4.1.8.18 8)) that stipulates that seismic forces cannot be resisted using friction loads and furthermore the structural commentaries specifically references the possibility of tanks "walking" under a seismic event.
My question is - would it be acceptable to provide lateral restraints at the bottom of the tank (i.e. angles bearing against the side of the tank) to prevent any lateral movement associated with sliding instead of anchors connected to the tank and foundation? I'm curious because the code is a little vague since it alludes to not using friction to resist sliding, yet it talks about walking which implies vertical movement. However the vertical movement is resisted by the self weight of the tanks which appears to be permissible by the code. Thoughts?
Thanks!






RE: Tank Lateral Restaints
RE: Tank Lateral Restaints
RE: Tank Lateral Restaints
RE: Tank Lateral Restaints
I think you need straps over the tanks to hold them down. Then, roll form some angles to the O.D. of the tank and 2-3' long and bolt the angles to the floor. You have to provide enough angles (lengths and angular location, in plan) so you are not applying the lateral loads to the bottom of the tank in such a concentrated way as to rupture/hurt the tank. And, maybe a rubber bearing pad btwn. the tank and the angles.
RE: Tank Lateral Restaints
Thanks!
RE: Tank Lateral Restaints
reason for not allowing frictional resistance against sesimic loads.
RE: Tank Lateral Restaints