Got an odd one here (at work)

I need to anchor a few wee structures into the ceiling of what is basicaly a granite cave

these things will weight 1/2 ton or so and will need to take a fee other loads aswell (so its got to be proper HD stuff) all with just 4 anchor each if posible

I've asked Hilti and they don't have anything
RAWL have a few mechanical ones rated for stone on there website (I've never used them before) but thats all I've found so far

what ever we do I need proper calcs that the customer will accept - anyone here know of a system ?

[Edited on 26/10/2010 by mcerd1]

Who did you speak to at Hilti? I know for sure that RE-500 works very well in granite and they DO have test data to confirm this. It may not be in the standard technical guide but they do have it. I worked for Hilti for 6 years. If you spoke to a sales guy then they will always walk away from anything that isn't concrete or brick/block construction. May be worth ringing head office and asking for the technical dept. If you tried that and they have said they cant help, then they are being abit silly as they have something that will do it.

Another point or question, these things that need suspending, somewhere along the line there must have been a technical drawing and or engineering proposal for these? What was specified? Having only 4 anchors means you will have to over specify each load bearing by 25% or have each anchor being loaded to only max of 75% of its designed amount. Obviously of any one fails to make sure the others are then not over stressed.
You have a difficult task ahead. I used to design fixing and calculate loads for Hilti and it was a mine field even with all the data. Good luck....

[Edited on 26/10/10 by AndyW]

Can the ceiling support half a ton? Strains my brain just thinking how you would work that out. How far would you have to drill upwards and fix before you could be sure the weight would not just detach a great slab of granite at it's next fault line above the cave. How sure are you there is reserve strength in the ceiling for this load? How can you determine faults and cracks above the ceiling out of sight?
Seems to me the mechanical fixing device is the least of your worries.

Are you looking for a product you can install or a supplied / fixed item?

I'd ask Selby Engineering & Lifting for something like this?

http://www.liftingsafety.co.uk/product/sala-concrete-wedge-anchor-3387.html

Mike

quote:

---

Originally posted by AndyW
I know for sure that RE-500 works very well in granite and they DO have test data to confirm this.

---

quote:

---

Originally posted by Guinness
I'd ask Selby Engineering & Lifting for something like this?
http://www.liftingsafety.co.uk/product/sala-concrete-wedge-anchor-3387.html />

thanks Mike, but its more this sort of thing I'm after:



[Edited on 26/10/2010 by mcerd1]

---

adithorp - 26/10/10 at 11:22 AM

"....if it is a problem the 'roof' is 700m thick so we should have a bit to play with..."

Simple then; Just drill through and put a plate on the top.

RAWL bolts will do the job but the variable is the stone.

---

Guinness - 26/10/10 at 11:28 AM

quote:

---

Originally posted by adithorp
Simple then; Just drill through and put a plate on the top.

---

I happen to know where there is a rig that has just finished a similar job. Do you want me to get a quote for shipping it over from Chile?

---

richardlee237 - 26/10/10 at 11:44 AM

You need to fit some type of expanding anchor (Rawlbolt).

Ensure that you have the test data for the anchor itself, then get a lifting company in to do a load test on each anchor after installing, they will issue a load test certificate.

You know it is safe and you have a cert to prove it to HSE, client etc

---

AndyW - 26/10/10 at 11:55 AM

quote:

---

Originally posted by mcerd1

quote:

---

Originally posted by AndyW
I know for sure that RE-500 works very well in granite and they DO have test data to confirm this.

---

thats as you say, but the only resin they say you can use upside down is the capsules (which they don't have test data for in stone )


You can use RE-500 Upside down FACT, they have a special sealing discs which need to be used. They also have installation data to confirm this in the tech guide.

as for the strength of the roof I don't think it'll be a problem its very deep in a fairly soild mountain and its up to the customer to check this (in this case anyway)
if it is a problem the 'roof' is 700m thick so we should have a bit to play with...

the 1/2 ton was just a guestimate - there is about 450kg of dead weight and I now know about 12kNm of moment at the roof (split between whatever anchors I end up with)



[Edited on 26/10/2010 by mcerd1]

---

[Edited on 26/10/10 by AndyW]

[Edited on 26/10/10 by AndyW]

[Edited on 26/10/10 by AndyW]

---

mcerd1 - 26/10/10 at 12:10 PM

quote:

---

Originally posted by AndyW
You can use RE-500 Upside down FACT, they have a special sealing discs which need to be used. They also have installation data to confirm this in the tech guide.

---

it was someone in there tech dep. that said you couldn't use it upside down, but as it turns out our customer want to use the mechanical ones if they can

---

tegwin - 26/10/10 at 04:48 PM

Can I be really nosey and enquire what exactly you are trying to hang? I am just very curious....

---

mcerd1 - 26/10/10 at 05:20 PM

quote:

---

Originally posted by tegwin
Can I be really nosey and enquire what exactly you are trying to hang? I am just very curious....

---

its just some boring HV eletrical stuff...

---