Steel Plate vs. Elastomeric Bearing

[KimWT]

I need a bearing pad to support the transfer beam which takes excessive loads from
exterior load-bearing walls of several floors in the precast concrete parking structure.
If I want to use a steel plate instead of elastomeric bearing pad, what factors should I consider?
(This will be located at 0.5" joint between transfer beam bearing plate and column corbel bearing plate.)
I am concerned about future corrosion problem.
Also, do you think it is really bad idea using a galvanized steel plate?

I am looking forward to your comments.

Thanks!

 

[KootK]

If I want to use a steel plate instead of elastomeric bearing pad, what factors should I consider?

You may want to give some consideration to the fact that a steel plate won't accommodate supported member rotation like an elastomeric bearing assembly will. You'll get high localized bearing stresses and potential for spalling at the front of your corbel.

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

 

[PittEng88]

Excellent points Kootk. You definitely want to consider beam end rotation and translation when designing a parking structure, and a elastomeric bearing pad will allow you to accommodate those movements a lot better than with a steel bearing plate. I would also like to add that elastomeric bearing pads provide great damping for your structure and will help reduce vibrations due to live loads and impact loading. Also, from an economical standpoint elastomeric bearing pads will more than likely be cheaper because they have pretty much no maintenance costs associated with them.

 

[EngineeringEric]

I have inspected numerous 'sliding' connections which are piles of rust. I don't think they move much anymore. Just another point to consider

 

[bridgebuster]

How excessive is excessive? Personally, elastomeric bearings are the better way to go. If rotations are a concern sliding plates could be a problem.

However, a steel bearing with a curved sole plate will also take care of the rotations - see attached drawing. I used these recently on a bridge project that involved widening an existing structure. Since the existing steel bearings will remain I used a steel bearing - copied from a 1970's DOT standard - rather than mix and match elastomeric with steel. These are taking about 60k.

If you want to use steel on steel (or more like steel on PTFE) Google Lubrite or Fluorgold. They'll have what you're looking for