Why unbalanced bevel groove weld? 1

[mike80]

I am reviewing revised shop drawings for a bridge and the fabricator has changed a weld detail. I am curious as to why he has changed the detail.

The original plans called for a complete penetration groove weld between the stiffener and the flange. The first submission on the shop drawings showed a 5/8 bevel weld with a 11/32 fillet weld on each side. The revised detail calls for a 15/16 bevel weld on one side and a 7/16 bevel on the other, both covered by a 11/32 fillet weld.

Since both are complete penetration welds, both are acceptable per the contract drawings. I am wondering what are the advantages of the unbalanced weld? I know I could call the fabricator, but I wanted to get a more broad spread of opinions.

Thanks for any input.


Mike

 

[metengr]

It might be that the weld detail was changed due to project schedule/cost (less time and cost required to complete a single-vee versus double-vee weld joint) or availability of welders.


Full penetration welds can be obtained if it is single-vee (back gouge and weld) or a double-vee configuration, as you stated. The only benefit or advantage I have seen with a double-vee weld joint is less distortion because the weld shrinkage is somewhat balanced.

 

[weldtek]

Sometimes it makes sense to put a deeper groove on one side. It could be for shrinkage / distortion control, or perhaps there's easier access from one of the sides, so it makes sense to do the backgouging and the majority of the welding from the side with the easier access.