Hole edge distance 6

[GD_P]

Hello,

I have a situation where the fastener drill/hole center has to be located on rolled beam (IPE140) such that the edge distance (dist between hole center to edge of beam) is only equal to hole diameter.
It is not a structural connection, but it is for mounting of equipment lug or base plate.
But as per the Eurocode EN 1993-1-8, min edge distance shall be 1.2 times hole dia.
I am worried how i can prove it?
This edge distance is used in calculation of the bearing resistance of the fastener, so just using actual above value in that eq will solve my problem?
Or
Am i suppose to weld a piece of plate on the adjacent edge in order to achieve it? (This will be messy, since there are many holes of such kind?
Or
Am i suppose to use the too heavy section than required.

The purpose of this bolts is merely to hold the equipment in position hence they are of non preloaded type.

It will be great, if someone could guide me?


GD_P

 

[WinelandV]

I can't speak to the Eurocode, but the AISC-360 allows for smaller edge distances than what is shown in table J3.4. Footnote [a] of table J3.4 states:

If necessary, lesser edge distances are permitted provided the appropriate provisions from Sections J3.10 and J4 are satisfied, but edge distances less than one bolt diameter are not permitted without approval from the engineer of record.

J3.10 deals with bearing strength at bolt holes. J4 covers strength of elements in tension, strength of elements in shear, block shear strength, and strength of elements in compression.

Thus, my understanding is that if needed, you can show that a smaller edge distance is permitable by checking the above failure states.

 

[BridgeSmith]

To a certain extent they are separate, but properly engineering a solution takes time and expertise, for which the engineer should be compensated. Approving something that does not meet the code requirements, without taking the time to understand why the code requirements exist, is risking a lot for very little reward.

 

[Lily_Linton]

My senior engineer from our Houston office told me once that minimum values stated on codes are only for guidance. If you can provide a technical analysis that your design meets the required capacity then it should be ok. But we are doing it once in a blue moon if we don't have any choice.
You gotta check for your UC though. If its around 0.90 then you have to think twice

 

[Agent666]

I find it interesting that AISC allow the minimums to be further reduced. Every other code (Eurocode/NZ/AU, etc) I've ever read, the word 'minimum' when associated with edge distances = absolute minimum, not acceptable to reduce further, world will end if you attempt to use less, etc. I find it interesting that if the EOR wants to or doesn't understand/appreciate what they are doing that they can go less than 1 bolt diameter. Minimums are there to protect against this type of engineer taking things into their own hands

In NZ, once seismic loading is involved (i.e. most structures), you need 2 times bolt diameter minimum edge distance in the direction of the load and 1.5 times the bolt diameter in any other direction. These larger distances are there to ensure plate tearout will not govern in connections under extreme inelastic demand (i.e. to suppress any brittle failure modes).

 

[ukbridge]

If I remember the old BS5400 values were 1.4d0 and 1.6d0 - in fact we generally allow for a slightly bigger edge distance to give the folks out on site a bit of an easier time.

@Dik I always strive (or at least try to be) a proponent of proper pencil and paper first-principles engineering, rather than the COP police. With that in mind things like bolts and connections are generally the last place I would start to look. If you want to benefit from the simple equations for something like bolts, you should respect all the limitations that are set out and not cherry-pick. I also agree with HotRod's point about lots of risk for little reward.

 

[GD_P]

Thank you all for your valuable comments.



GD_P