Weld Symbol For Rebar to WF Column 1

[metrosteel10520]

Thank you all for taking the time to read this.

I have a question about welding rebar to the flanges of a wide flange column. The design called out a flare beveled groove weld, see attached. We used this weld where it applies, where the rebar is parallel to the flange. However, where the rebar is perpendicular to the flange this weld is not possible. We used a ½”filet weld-all around at this location. The Project Engineer was looking for a Full Penetration Weld to be applied here. Does the ½” Fillet Weld bring the rebar to full strength and thus satisfy this requirement?

Thanks in advance.

 

[slickdeals]

See the PCI design handbook for weld strength requirements for rebar. It has been discussed here many times before as well.

 

[slickdeals]

Curious as to what is trying to be achieved here with these details. Braced frame shear transfer back to a grade beam?

 

[MrHershey]

A-A indicates the pad footing is for a moment frame. First thought was maybe not enough passive resistance to resist shears at base, but seems like a somewhat inefficient way of resolving that issue when you could just tie footings together instead...

Also says grade beam is 'embedded in mat slab', so maybe there's liquefaction issues and the grade beam is acting as a chord and the reinforcement is intended to transfer the chord force at the ends into the moment frame column to then transfer into the pad footing? Would question how the pad footing is working with liquefaction though.

I too am curious as to what welding the reinforcement to the moment frame column is attempting to accomplish here.

 

[BAretired]

Looks like an attempt to develop fixity at the bottom of the column.

BA

 

[ztengguy]

Sort of like a hair pin reinforcing?

 

[BAretired]

For the interior columns, holes could be shop drilled through the flanges at rebar locations. In the field, bars of length 10' + D(col) could be inserted through the holes without welding to either flange. If the engineer is willing to replace 3-#6 with 2-#7 or 2-#8, no welding would be required.

If you must weld bars to the column flanges, an all around fillet weld is acceptable but is difficult to do with bars in close proximity to each other. I prefer a simple V-groove facing up so that all welding is down-hand.

BA

 

[BAretired]

For end columns, I may be misreading your plan section, but if the inside bars are bent at 90 degrees, the detail is unacceptable as shown as neither leg is adequately anchored.

BA

 

[dik]

I'd typically call those up as fillet welds unless the rebar was prepared with a bevel...

Some of your details are difficult to construct, and I assume the rebar are dowels only to be lapspliced with other rebar.

Dik

 

[JAE]

BAretired - I just saw that too and then read your post. Bad detail turning bars 90 degrees along an inside face at a re-entrant corner.

If I saw that weld symbol on the rebar, I would think the engineer was intending for the rebar to be cut at the ends (like a curved chisel cut) to form the flared bevel weld - a full pen weld on the rebar.

 

[hokie66]

Agree with BA and JAE about the bar that goes around the reentrant corner...the one that is not welded to the column. Unacceptable.

As for the welds, where the bar butts the steel, a full penetration bevel is appropriate, and a fillet weld is not as good. Where it lies alongside the flange, it would be a fillet weld, just a shaped one.

 

[hokie66]

And a word of advice...don't double post. It is frowned on. I have redflagged your post in the welding forum.

 

[slickdeals]

@metro,
See attached.