Tilt-up External Free-standing Firewall Connection
Tilt-up External Free-standing Firewall Connection
(OP)
I'm looking at using precast concrete panels, approx 8m high x 3 m wide, cantilevered from the base.
Are there any recommended clever methods of achieving a fixed base? At this stage I would consider both; footings cast before and cast after the erection of the panels.
Thanks.
Are there any recommended clever methods of achieving a fixed base? At this stage I would consider both; footings cast before and cast after the erection of the panels.
Thanks.






RE: Tilt-up External Free-standing Firewall Connection
You can also set the panels on a regular footing and tie the panels to floor slabs. Need to make a positive attachment to the floor slab. This method restrains the slab, meaning more likelihood of undesirable shrinkage cracking.
Having said this, if these are external bearing walls, cantilevered walls should not be used. Walls should be designed to fall inwards when the steel collapses. A wall which is cantilevered will curl in an intense fire, making it lean out. The steel will be tensioned, and the connections can fail instantaneously, causing the wall to fail and fall out.
RE: Tilt-up External Free-standing Firewall Connection
They are freestanding firewalls between transformers in a sub-station, so no issues re connection to steel framing.
RE: Tilt-up External Free-standing Firewall Connection
When in doubt, just take the next small step.
RE: Tilt-up External Free-standing Firewall Connection
RE: Tilt-up External Free-standing Firewall Connection
what do you mean when you say a positive attachment?
RE: Tilt-up External Free-standing Firewall Connection
RE: Tilt-up External Free-standing Firewall Connection
I mean providing a tie between the wall and the slab. Something like spats showed, but it can be done with ferrules and screwed in bars or in other ways. Don't just depend on the slab each side to restrain the wall, as the slab will shrink away from the wall.
RE: Tilt-up External Free-standing Firewall Connection
Those number4 dowels would be a pain, better to have a cast in threaded insert (ferrule) that wont get in the way during lifting.
I do love the footing detail though (when its necessary) I have used similar myself.
RE: Tilt-up External Free-standing Firewall Connection
I would never consider using the slab for the stability of the wall anyways. What about when it's under construction? You can't remove the braces until the slab is in. What if they decide to cut out the slab in the future, not knowing it's integral to the stability of the wall? Besides, you would have to bury the footing deeper to get a decent moment arm between the slab and the footing. All-in-all, not a good idea, in my opinion.
cds72 - I assume your talking about the slab dowels. Not a problem at all. I've been using them for 20 years and haven't gotten any complaints. They're easily tied to the reinforcing mat, and are not in the way at all during lifting.
RE: Tilt-up External Free-standing Firewall Connection
RE: Tilt-up External Free-standing Firewall Connection
I agree with the issue regarding the cutting of the slab - it does happen. But if there is a roof at the top restraining it then it will be stable under normal conditions.
RE: Tilt-up External Free-standing Firewall Connection
cds72: since we were talking about cantilevered walls, there is no roof to brace at the top.
RE: Tilt-up External Free-standing Firewall Connection