CONSTRAINTS FOR SKID SUPPORTS IN STAAD PRO
CONSTRAINTS FOR SKID SUPPORTS IN STAAD PRO
(OP)
We outsourced the structural design of skid . It has 6 supports with base plate which will be attached to foundation with anchor bolts. He has considered the joint as pinned at support. I do not understand why he has considered pinned. According to me , it should be fixed as rotational moment is not possible.






RE: CONSTRAINTS FOR SKID SUPPORTS IN STAAD PRO
I found the last acceptance in written of the pinned assumption whilst reading some modern british recommendations for 1 story industrial buildings, where the assumption was acceptable if baseplates had just up to 4 bolts.
A proper answer to your question requires the examination of the problem, with the proposed set of loadings and structural responses linking loadings with reactions.
RE: CONSTRAINTS FOR SKID SUPPORTS IN STAAD PRO
RE: CONSTRAINTS FOR SKID SUPPORTS IN STAAD PRO
Respect the risk of undersizing the foundation with the pinned scheme, at least in buildings it must not be a very significant problem, since you have a notional scheme able to sustain all the loads above and pass such loads to the foundation; your columns, baseplates, and foundations will be of necessity sized to sustain such loads at the limited deformations required at both service level and limit load level, and experiencie proves the scheme has been used successfully in many occasions without problems -a result on which the generous sizing of concrete footings and conservative estimate of the working bearing loads at the foundations may have been having a say.
You may be right in that a more deeper identification of the solicitations may be necessary, particularly in cases where middle to high cycle dynamical actions are present, and then improper considerations of some actions actually present, typically tensile action on the bolts from moments, may cause unforeseen failure. This has happened lots of times with road signal structuras and of course foundations of machines.
RE: CONSTRAINTS FOR SKID SUPPORTS IN STAAD PRO
It's common practice to assume it as pinned.
There is no such thing as "true pin". The assumption is always, is it near pin or near fix.