The only thing that DOT would approve was to set the form in place and hold on to the form while a second line lowered the pre-tied cage into the form. At that point, the form is lifted a few feet to allow the cage to be tied to the dowels of the previous pour. This probably is more dangerous...
We recently had an accident where the 2nd lift of pre-tied rebar on a 12ftx4.5ft bridge column collapsed when a guy cable broke (do not yet know what broke the cable). The pretied column simply bent over (staying tied to the first pour projecting steel) like a limp weiner and stayed completely...
