general questions
general questions
(OP)
1) For the old-time hydraulic calc's: was it 1 foot neglected on each side of the pier to account for debris buildup, was it 18 inches??
2) What is the reason for greasing the top of an elastomeric bearing and installing a smooth plate above it: It's not a sliding bearing it's supposed to deform what would be the point of the calc's and the movement rating?
Many thanks.
2) What is the reason for greasing the top of an elastomeric bearing and installing a smooth plate above it: It's not a sliding bearing it's supposed to deform what would be the point of the calc's and the movement rating?
Many thanks.





RE: general questions
As for greased bearings I've never seen a greased elastomer bearing...but I bet I haven't seen a lot thing either...Been around since dirt though!
Regards,

Qshake
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RE: general questions
RE: general questions
I'm not talking about free board. I'm thinking of the old Railroad bridges, the kind with the concrete pier walls, the channel was analyzed assuming the the pier width plus 18" on each side of the pier and after a big storm the piers are vertical so there is indeed a big pile of debris in front of the piers taking up about an extra 18" on each side. I'm thinking around the 1900s this was a standard: I can not find it published. But, there are only a few pre WW2 books I own.
The greased bearing is used to relieve the shrinkage of the concrete, mainly in post tensioned. But of course all off this does not provide comfort: has anyone had experience where this worked over a long period of time. I haven't yet thought of anything wrong with it. I think I've read somewhere that galvanizing does not react well with concrete, but other than some vague recollection this doesn't help--suppose it could always be some other type of metal. If it works so well why isn't it used as a standard for all elastomeric bearings? Has anyone had elastomeric bearing walk away? Walk away because of loss of top fixity?
RE: general questions