Tilt-Up Connections 2

[PJHudson]

I am working on a Tilt-Up warehouse in central California and I would like some feedback about a detail for supporting purlins at a panel joint. I have seen photos of similar details but I am not sure they are appropriate for my project. The proposed detail involves placing an embed with 4 Nelson Studs on each side of the joint beyween two panels and welding a heavy angle across to support the purlin. My concern is that it is a rigid connection at the edge of a panel, and thermal stresses, foundation settlement and seismic loads might cause the connection to crack or fail. The warehouse will be in a relatively low seismic region of California.

Does anyone have experience with similar details and have you heard of any problems with a detail such as this? Can you refer me to someone who might be familiar with this kind of design?

Thank you for any help you can offer.

 

[msquared48]

If this is at the level of the chord tie which is a rigid element, it may not be an issue.

However, it does point out the perennial problem of detail flexibility in these connections where a rigid tension tie is needed at the diaphragm level to resist the chord force. FYI, there is a connection to satisfy this problem, but it probably is not incorporated into your building if it is very old.

Mike McCann
McCann Engineering

 

[hokie66]

I have seen the corners crack on tilt up panels because of the type connection you describe. The reasons this can happen are as you listed, with the addition of restrained drying shrinkage of the panels. If bolts or studs in adjacent panels are joined rigidly by a steel member, I always require that they be at least 24" from the edge.

 

[PJHudson]

Thank you Mr.McCann and hokie66 for the input.

This is a new structure, in plan check. We are planning to move the embeed plates further from the edge, but I have heard of other details such as slotted connection on one side. I am also interestd in more specific suggestions as well.

Thanks for you consideration.

 

[hokie66]

If the angle is discontinuous, a slotted connection on one side would work, as long as the discontinuity is on the same side as the slotted connection. As you indicated the angle is to support purlins, you should be able to break the angle at the correct positions. But an embedded plate with Nelson studs on each side of the purlin does seem very heavy for just a purlin support. Perhaps you can elaborate on your roof bracing scheme.