beam connection to precast wall

huangyhg

beam connection to precast wall
for a steel beam/precast wall connection, the fabricator is calling out a double angle with slotted holes in the angle. is this a common thing, or should the slotted holes be in the beam?
thanks
jim

i've never seen slotted holes provided in the beam web, but i've only been around for 2 years.
the slotted holes are common, and they should be in the angles.  this is allow more flexibility/tolerance in the placement of the wall and beam.  
how does this effect the lateral support of the panel from the beam?
i had a similar situation once where they wanted to use slotted holes, i actually made them weld the washers on so that the snug tight bolts still took axial load into the beam.
if there is no direct transfer of load between the two then this is not an issue.
we are just the precast wall designer, and thru the structural drawings are indicated to supply the beam to wall connection. i argued that anything outside the plain of our panel is the eor's design, etc. but, since we are supplying, we are going to use material, techniques that are the least expensive for us. all the loads are just gravity as called out on the drawings.

slots should be in angles. fabricator can work with small angles easier than with a big beam.
i usually will put in slotted holes for erection and  field adjustment and then field weld them once in final position.
the panel is stabilized by the edge angle that should be bolted to the wall or welded to an embed plate in the wall.  otherwise the wall has to span horizontally between beams which can be a great deal further than the bolt spacing.  
as the supplier of the precast wall panels, you should be wary of the prying forces which this type connection can apply to the wall as the beam deflects and the end rotates.  there are better connections for steel beam to precast wall.
if at all possible i dont like the idea of slotting holes anywhere.
hokie66 suggested a very smart connection of a beam to a tilt up panel in a previous post.  there are no slots in this connection and its very neat.