2.66:1 Safety Factor for Lifting Anchors on Precast Insulated Wall Panels

[530_3D]

Every precast lifting anchor catalog has the option of using 2.66:1 safety factor in lieu of the typical 4:1 for precast. OSHA lists 4:1 for precast, other than tilt-up.
Does anybody have insight on when its acceptable to use 2.66:1 for plant-built precast insulated wall panel lifting anchors that are only used one time

 

[JStephen]

Not my field, but I was curious and googled:

From this link, printed page number 46:

https://surebuilt-usa.com/docs/Precast-Concrete-Accessories.pdf

Notes:
1 The 4:1 safety factor is used with precast work and normally requires no increases except for cable magnification. Additional increases due to unusual live loads or cable magnification may be required for some applications.
2. The 2.66:1 safety factor, is a 2:1 safety factor, which is commonly used when back shipping (I think should be "stripping"?), increased 33% to compensate for initial bond and impact. Additional increases due to unusual live loads or cable magnification may be required for some applications.

From this link:

https://www.emisupplies.com/precast.html

The 2.66:1 safety factor is a 2:1 safety factor, which is commonly used when back stripping, increased 33% to compensate for initial bond and impact. Additional increases due to unusual live loads or cable magnification may be required for some applications.

 

[Brad805]

Precast suppliers are more skilled at handling panels than tilt-up contractors in my opinion. Tilts are lifted once by various persons. Precast is moved after demould, loaded onto a truck, and finally erected on site. Dropping panels is bad for business, so they take it serious. The company I work with allows two different people to move the panels, and have developed loads they are comfortable with over 20 years of practice.