Base shear through anchors, Anchor bolt hole size & Eurocodes 1

[GD_P]

Hello,

We have fixed column baseplates with anchor (M20) hole dimensions (dia = 22mm) same as for normal bolts holes assuming anchor rods will be cast in place with templates. But the floor is ready without anchor cast in place and hence the civil person will make subsequent anchoring (drilling & placing the anchors in floor). Our scope of work s limited to design & fab of steel str & base plates.
Is the current anchor rod hole allowance (normal holes) sufficient for subsequent anchoring?
I am using the Eurocodes, where I dont find any guidelines for allowance.
SCI P358 does specify 6 mm allowance over the anchor size, but P398 does not specify any value?
I think it shouldn't be related to type of base plate : fixed type or pin type?

The anchors are required for transferring the shear. As base plates are already fabricated, making holes oversized will have below limitation:
1) Bolt edge distance is 30mm, so I can only go upto hole of 25mm dia. to comply min edge dist criteria of 1.2d0
2) Sizing of the washer, max hole dia upto which the normal washer with 3 mm thk can be used. If it is not sufficient how to decide its thk & dimensions?
3) Is it necessary to fulfill min edge dist criteria for welded washers which are used for transferring shear?

AISC allowances are too big to accommodate in current baseplates.

Please share your opinion.
Thanks in advance.


GD_P

 

[klaus.]

Try Hilti or similar fasteners

 

[drbrainsol]

The Eurocode is unfortunately lacking when it comes to the design of holding down assemblies, particularly for post installed anchors. What you should be looking at is the European Technical Approval Guideline ETAG 001 - Metal Anchors for Use in Concrete. Hilti Profis (free design software from Hilti) is based on the ETAG. One of the most useful pieces of software there is for this sort of problem.

Bolt hole clearances are actually very tight for applications meant to support shear loads through the anchors. This is to ensure all the anchors are engaged equally. Hilti have specific products to deal with this problem.

 

[GD_P]

Thank you Klaus & drbrainsol.

Is it really free of charge, since in the guidance notes for installation it talks about the license key?
Kindly correct me if I'm wrong.

GD_P

 

[Tommy385]

You can also use Fischer anchors, they have also ETA and the program is free.