Raising a steel column primarily involves using a crane to lift and position the structural element safely into its designated place on a foundation or supporting structure.
To effectively and safely raise a steel column, several critical factors must be considered, especially relating to planning and execution with lifting equipment like cranes. Based on standard practices and referencing the provided information:
Key Steps for Raising a Steel Column
Raising a steel column is a precise operation requiring careful planning and execution.
- Determine the Column's Weight: It is absolutely essential that the mass (weight) of any steel must be known for lifting into place. This information is fundamental for selecting the appropriate crane with sufficient lifting capacity and reach.
- Plan the Lift: This involves assessing the site conditions, determining the crane's position, calculating the lifting radius, and identifying potential obstructions.
- Select the Crane(s): Based on the column's weight, dimensions, and the required lifting height and radius, select a suitable crane. Sometimes, as referenced, when ordering cranes to raise columns, a second crane may be required to "float" in the base. This "floating" process might be needed to accurately align and hold the column base during initial connection (e.g., bolting to anchor bolts).
- Prepare the Column: Ensure the column is ready for lifting. This includes attaching lifting lugs or preparing points for slings. Check that base plates, splice plates, or other connections are ready.
- Sling the Column: Proper rigging is vital. To ensure that columns hang vertically during the lift, they should be slung as near to the top as possible. Slinging near the top helps balance the column and prevents it from swinging or tilting excessively. Use appropriate slings, shackles, and spreader bars if necessary.
- Lift and Position: The crane operator, guided by signalers, carefully lifts the column. The column is then maneuvered over its intended location. If a second crane is used, it assists in controlling the base while the main crane manages the majority of the load and the vertical positioning.
- Secure the Column: Once the column is in position, it must be temporarily secured immediately. This typically involves installing temporary bracing or making initial connections (like bolting to anchor bolts) before releasing the crane load.
- Final Alignment and Connection: After temporary securing, the column is checked for verticality (plumb) and alignment before final connections are made (e.g., tightening bolts, welding).
Essential Considerations
- Safety First: Always prioritize safety. Ensure a clear lift path, manage personnel exclusion zones, and follow all site-specific safety protocols.
- Site Conditions: Assess ground bearing pressure for the crane, overhead obstructions (power lines!), and wind conditions.
- Crew Coordination: Clear communication between the crane operator, signalers, and erection crew is paramount.
Raising steel columns is a standard procedure in construction, relying heavily on accurate planning, correct equipment selection, and skilled personnel to ensure structural integrity and site safety.
| Step | Description | Key Requirement / Note |
|---|---|---|
| Weight Determination | Knowing the exact weight of the column. | Must know the mass (weight) to select the right crane. |
| Crane Selection | Choosing a crane (or cranes) with adequate capacity and reach. | May need a second crane for the base ("float in"). |
| Rigging | Attaching slings and hardware correctly for lifting. | Sling as near to the top as possible for vertical hang. |
| Lifting & Positioning | Operating the crane to lift, swing, and lower the column into place. | Requires skilled operator and clear signals. |
| Securing | Temporarily bracing or connecting the column until it is stable. | Immediate action after positioning. |
Successfully raising a steel column ensures the vertical load-bearing elements of a structure are correctly installed, setting the stage for subsequent construction phases.
