Fixings calculations (support and restraint anchors)

Hey guys,

I'm currently on my a placement for Civil Engineering and have had to deal with the calculations for this company. The only problem is that most of the time I get stuck and do not know who to ask because there are no structural engineers there and if I want to email someone to confirm a calculation I have to either be interested in using their product or be placing an order. HELP!

So fixings are these metallic pieces that are usually used to hold stone cladding. I have to calculate/ prove that a 12dia. support anchor (type of fixing) can hold a maximum load of 412N.

Anyone?

Original post by Jaguar_94

Hey guys,

I'm currently on my a placement for Civil Engineering and have had to deal with the calculations for this company. The only problem is that most of the time I get stuck and do not know who to ask because there are no structural engineers there and if I want to email someone to confirm a calculation I have to either be interested in using their product or be placing an order. HELP!

So fixings are these metallic pieces that are usually used to hold stone cladding. I have to calculate/ prove that a 12dia. support anchor (type of fixing) can hold a maximum load of 412N.

Anyone?

Has this to be done to a design code? Or is a first principles calculation sufficient?

Reply 2

Jaguar_94

OP

Original post by Smack

Has this to be done to a design code? Or is a first principles calculation sufficient?

Thank you for your response and apologies for taking so long to respond back (got caught up with work). I've attempted using first principles but again not too sure if I am correct. However I believe my boss wants me to attempt it using the codes- he gave me a sheet of previous calculations for me to look at but it's a little bit difficult to understand as I'm not familiar with it, maybe I can send it to you?

Original post by Jaguar_94

Thank you for your response and apologies for taking so long to respond back (got caught up with work). I've attempted using first principles but again not too sure if I am correct. However I believe my boss wants me to attempt it using the codes- he gave me a sheet of previous calculations for me to look at but it's a little bit difficult to understand as I'm not familiar with it, maybe I can send it to you?

If you could post what you have done so far that would be helpful, and would also allow others to help as well. Whilst I would not actively object to you posting the sheet of previous calculations, you'd have to find out whether it is okay for you to be sharing such information.

What codes are you expected to use to perform this calculation? I'm not sure how much help I could be, but if you post what you've done so far I'll see what I can do.

Original post by Jaguar_94

Yes that's what I am worried about...nonetheless I will try and write out their calculation myself without giving too much away and post that instead but I think some of the things they have done are visible in their website so it shouldn't be too much of a problem.

The code is an adapted design method by "The steel Construction Institute" 1995 (SCI-P-157) (you can download it for free from their website if you're a student).

I've attached what I have done so far and if you're unsure/confused of what I've done I'll be more than happy to explain it. Thanks for your help!

I'll have a look later to see what I can do.

I would like to advise though that rather than type your calculation up in Word, it might be better to use Excel (or MathCAD if you have access to it).

Reply 5

Jaguar_94

OP

Original post by Smack

I'll have a look later to see what I can do.

I would like to advise though that rather than type your calculation up in Word, it might be better to use Excel (or MathCAD if you have access to it).

Thanks

Yes, actually I will have to type it out on excel later on for my manager to use as a guide for future projects. After I've figured out how to do it I will complete it (I've started but yet to finish).

By the way, I'm concerned that what I've done doesn't prove that a 12dia. anchor is able to support that weight, which is the problem with first principles because you don't have anything to base it to, whereas codes give you limits..but i'll let you to have a look :smile:

Original post by Jaguar_94

By the way, I'm concerned that what I've done doesn't prove that a 12dia. anchor is able to support that weight, which is the problem with first principles because you don't have anything to base it to, whereas codes give you limits..but i'll let you to have a look :smile:

Yes, usually the code will give you an allowable limit based on the geometry and material properties of the component (at least the ones I've used do). Nonetheless, from a purely first principles approach you could also consider using something like the Von Mises or Tresca criteria.

Also, what material is the support made of, or what are its properties? (Mainly yield stress, ultimate stress and Young's Modulus that I am interested in.)

Original post by Jaguar_94

Hi there, apologies once again for the late reply. Von Mises and Tresca criteria are new to me, but if you think it'll work then we could give it a go.

I don't know all it's properties however I do know that we will be using a Stainless steel of grade 316. I googled this type of steel and I found a document that seems somewhat reliable(I've attached it below). I've also written out an example of a previous project we did but I couldn't tell you the type of fixing that was used. However in that example it stated that they used injection resin FIS-V, we will be using injection resin FIS V 410 which will give me a tensile capacity of around 1.7kN per anchor per Block.

I've also attached the support system calculations done by one of our clients, I think my manager wants me to produce something like that. But the most important thing is to prove that the 12dia. anchor passes all the checks.