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RE: Verification test

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Hi Jim

Thanks for the response.  Yes, it's a reasonable value of that suction that 
 I'd like to assume for different types of lift process.  It seems the value 
 is not a single one.  At this end, I have asked the supplier here if he had 
 used a load cell.  He reply was, "yes" and that very little extra load above 
 the panel weight was registered so I'm assuming it's a function of the lift 
 technique and the bond breaker used.  I have seen a few processes where the 
 fabricator has actually gone around the slab while a small lift load applied 
 and crowbarred the slab off the floor.  And I have seen an instance where 
the slab was broken during an edge lift. That suggested that while the bond 
 may have release at the edge there was still "grip" along the panel.  That 
 was a few years ago when they just used form oil so that probably a good 
sample to quote.

I've done this before with an assumed value based on the surface tension of 
 the oil/release agent given by the supplier but in this case I am aligning 
 an off-shore anchor lift system with the requirements here so I'd like a 
more definitive (range of) value - if there is one.

Thanks

Thor

-----Original Message-----
From: seaint-seaosc(--nospam--at)mail-list.com [mailto:seaint-seaosc(--nospam--at)mail-list.com] On 
Behalf Of Jim Getaz Sent: September-03-15 6:51 AM
To: seaint-seaosc(--nospam--at)mail-list.com
Subject: RE: [SEAINT-SEAOSC] Verification test

	Thor,
		As a plant-cast precaster, tilt-up is a dirty word, but we think that "bed 
 suction" is about the same as the weight of the panel. So a crane will exert 
 20,000# momentarily to free a 10,000# panel from the casting table. Therefore, 
 the crane operator tries to lift one edge first so he's only exerting 10,000# 
 to lift half of a 10,000# panel. Lots of texture on the form is assumed to 
 increase suction. Is that what you're after? Jim Getaz

-----Original Message-----
From: seaint-seaosc(--nospam--at)mail-list.com [mailto:seaint-seaosc(--nospam--at)mail-list.com] On 
Behalf Of Thor Tandy Sent: Wednesday, September 02, 2015 7:04 PM To: 
seaint-seaosc(--nospam--at)mail-list.com Subject: RE: [SEAINT-SEAOSC] Verification test

OK, here's one.  What's a good (design) value for face loads on a tilt up 
panel at liftoff from the bed/slab?

Thor A. Tandy P.Eng, C.Eng, Struct.Eng, MIStructE, FEC Victoria, BC Canada
Email: vicpeng(--nospam--at)telus.net
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