Shear Capacity of Anchor/ Expansion Bolts

[Suthees]

Hi,

1) In Base plate Design, Shear capacity needs to be reduced by 20%(because of bolt bending) as per ACI 318-02 if grout pad is used

And AISC SDG 1 p.29 specifies Based on shear friction theory, no bending of the anchor rod within the grout need be considered.

Please clarify

2) Is there any change in the shear capacity of bolts if the base plate embedded in concrete/ concrete screed .

Thanks
MKS

 

[JedClampett]

First of all, you need to get a newer edition of ACI. A lot of revisions have been made since the 02 one.
In looking at the ACI 318-14, it appears that for anchors embedded as you describe, you just don't have to reduce them by the grout pad factor. However, if you have embedded anchors welded to a plate, you get a different formula, 17.5.2.3 as an option, which is 14% higher than the non welded one.

 

[wannabeSE]

Jed,
The steel strength in shear is reduced for a grout pad per 17.5.1.3.

Suthees,
You should look at the Design Guide's 2nd printing of the 2nd edition. But, There doesn't look like there ismuch cange to the passage you quote.