- What wind velocity should panels be braced for?
Most panels are designed for a 70mph wind in accordance with the TCA's GUIDELINE for TEMPORARY WIND BRACING of TILT-UP CONCRETE PANELS DURING CONSTRUCTION
- What safety factor is necessary for brace design?
Most designers use a minimum safety factor of 1-½.
- How many braces are needed per panel?
A minimum of two are needed for aligning the panel, but large panels require more. Check with the design charts provided with the erection design for type and quantity of braces.
- When should the braces be attached to the panel?
When they are still on the casting bed if at all possible. It speeds and simplifies the erection when the braces are raised with the panels.
- When and how should braces be removed from panels?
The panel should be removed after the roof connections and/or diaphragm are completed. Braces should be disconnected from the floor first, and then carefully disconnected at the top and lowered to the ground. If they are dropped or allowed to slide down the wall, they may be damaged.
- Is knee bracing and cross lacing of braces a good idea?
It complicates and prolongs the lifting because it must be in place before the crane is released. While it is expensive to do, it is sometimes necessary on tall panels in windy areas.
- Is cable bracing adequate for panels?
If correctly placed and connected, it can be effective. It is more difficult to adjust or plumb panels with cables than with braces, but exceptionally tall panels may require it.
- Are there any precautions necessary when bracing to the floor?
Be certain that the floor is of adequate thickness and strength. The inserts should not be near edges or joints, and must be placed in large enough slab sections to withstand uplift forces.
- What do I brace to if the floor isn't available?
Have a deadman designed for job site conditions, including the soil type and grade elevations.
- Can drill-in expansion type anchors be used?
Some types can be permitted they are installed per the manufacturer's guidelines. The majority requires some skill and certainty of setting that is not always obtained. Even when properly set, the working load with a 4-to-1 safety factor on ¾ inch expansion anchors is much lower than the design load of most Tilt-Up braces.
- How do I brace and shore lintel panels?
The panel bracing and shoring should be designed by a professional engineer, and the shores should be braced against lateral movement separately from the panel. All members should have firm bearing on adequate foundations, and the connections should be fixed before releasing the panel from the crane.
Building with Tilt-Up | Frequent Questions