New opening in Tilt Panel
New opening in Tilt Panel
(OP)
I have a project where we are cutting some new small openings in existing tilt panels (Seismic design category D). The plan reviewer has requested "reinforcement, or metals equivalent to 2-#5 all around concrete wall opening".
Does anyone know why this might be needed? I don't need it for strength. Unfortunately, the reviewer is out of the office- and we are trying to resubmit as fast as possible
Thanks
Does anyone know why this might be needed? I don't need it for strength. Unfortunately, the reviewer is out of the office- and we are trying to resubmit as fast as possible
Thanks






RE: New opening in Tilt Panel
I bet that is where he is coming from.
RE: New opening in Tilt Panel
May require fire protection.
RE: New opening in Tilt Panel
I think the logic for the steel channel is that it acts as a tension tie.
The panel is probably designed on a per foot basis for wind loads. Once you cut the opening, you will have to account for this loss of reinforcing and what will pick up this load.
It's no trick to get the answers when you have all the data. The trick is to get the answers when you only have half the data and half that is wrong and you don't know which half - LORD KELVIN
RE: New opening in Tilt Panel
What has anyone done the meet this minimum jamb steel requirement? Channels or steel plate is one way, but is it really acting as intended? I don't see how you can get good enough anchorage to make this function as rebar would.
To discuss theory- What is the purpose of these bars in the first place. I believe that this is probably intended for crack control at the high stress points created by openings, primarily generated during curing. If that is the sole function of this rebar- then it is basically useless and not necessary when cutting openings in existing panels. Comments?
RE: New opening in Tilt Panel
As a deep beam, check it for the next horizontal beam up, chances are, its going to work. For the out of plane wind load, you can check each leg left over in the panel, if the opening is not at the center (or location of max momemt) and you can show there is enough vertical steel remaining, chances are your going to be ok. What size opening and what width of panel do you have? For crack control you can cut circular holes at the corners, and then grout in the door, window, etc. hopefully the flashing covers the cuts. If it cracks, then the grout should crack, and not the panel.
RE: New opening in Tilt Panel
If the Architect complains, blame it on the reviewer.
Mike McCann
MMC Engineering
http://mmcengineering.tripod.com
RE: New opening in Tilt Panel
My understanding of a strongback is when you have a narrow jamb on one side of the opening which gets strengthened. If the panel was designed originally with no opening, there probably is no existing strongback?
It's no trick to get the answers when you have all the data. The trick is to get the answers when you only have half the data and half that is wrong and you don't know which half - LORD KELVIN