design of precast chess table

[esj]

I am working with a precast concrete manufacturer who has installed some chess tables and chairs in a park. Some of the table tops have broken loose from the pedestals that support them. I need to engineer a conncetion between the pedestal and table top. Does anyone know of a standard that give any design loading criteria for this or similar conditions - picnic tables maybe?

 

[jike]

No standard that I am aware of. I would think that you need to design for some unbalanced loading such as someone standing on top of one side of the table.

 

[esj]

Exactly - I'm thinking a 300 lb load, like we design stair tread for, but I wanted to see anyone knew of any standards that were specific to tables.

 

[rnorth]

step 1. remove the slab if possible
2. survey top of posts and shim to exactly level w/ plastic or steel
3. place a bed of non shrink grout (very little water in the mix)
4. set the slab
5. attach clip angles w/ 1/2" hilti anchors.

 

[jike]

You might even want to include an impact factor. I could envision a vandal jumping up and down on the edge to break the connection.

 

[rb1957]

if a vandal hurt himself, doesn't he deserve it ?

if a vandal hurt himself, would he sue ?

but you should be able to think of a number (300 lbs sounds good to me) and double it (and you'll be twice as safe)

 

[apsix]

"if a vandal hurt himself, doesn't he deserve it ?"
Possibly, up to a point. But what if the person is not a vandal as such, just someone in high spirits jumping on the edge of a robust looking platform.
I think there is some duty to ensure that the strength of connection is not too far removed from the rest of the structure.
I vote for the 600lb load.

 

[jike]

It is not to difficult to imagine an attorney claiming the connection was inadequate`and this contributed to the injury of the vandal or person in high spirits.

 

[pba]

What would be really good is to engineer a connection which allowed for a plastic failure rather than a sudden elastic (catastrophic) type of failure. How to do this, I'm not sure.

Rebar in concrete does tend to have the right type of performance but resin anchors tend to result in shear failures so there is some clever working out to be done to firm up the concept - Good luck...

 

[jec67]

I worked on a table design a few years back. I talked with an engineer at Steelcase (commercial furniture manufacturer) who gave me some design criterion that they follow in their designs. I do not recall the criterion off hand, but you may want tl call them and talk to someone in engineering.