Understanding the Role of Packing Plates in Steel Structures

Introduction to Packing Plates

A packing plate in a steel structure is a flat piece of material, typically made of steel, used to fill gaps or spaces between structural elements. These plates play a crucial role in maintaining the stability, safety, and integrity of a steel structure, serving several important functions.

Purpose and Functions of Packing Plates

The primary purposes and functions of packing plates include:

Load Distribution: They help distribute loads evenly across connections or joints, reducing stress concentrations that could lead to structural failure. Alignment: Packing plates assist in aligning components during assembly or installation, ensuring that structural members are positioned correctly. Adjustment: These plates allow for adjustments in height or elevation of steel members, helping to achieve the desired level or slope in a structure. Connection Enhancement: They can enhance the connection between two structural elements such as beams and columns by providing a larger surface area for welding or bolting.

Application and Usage

Packing plates are commonly used in conjunction with other structural elements like beams, columns, and brackets in various construction applications. If two unequal thickness plates are connected in a butt joint, a packing plate ensures that the gap is filled appropriately, which is particularly useful when the thickness difference exceeds 6mm.

Practical Use Cases

Column Alignment and Foundation Leveling:

After the erection of steel columns, they need to be aligned vertically and to maintain the elevation level. Once the alignment is completed, packing plates are placed between the column’s base plate and the foundation top to keep the column rigid. Grouting is then done to ensure a secure fit.

Non-Welded Connections:

Packing plates are not recommended for welded connections or critical moment connections such as slip-critical joints. For these applications, high-strength bolts are used to firmly join the mating surfaces. Packing plates are only effective in non-welded, bolted connections.

Protection Against Moisture and Insects:

The primary purpose of packing plates, also known as filler plates, is to fill gaps between main structural components such as in double cover butt joints. If filler plates are not used, water and insects may enter the gap, leading to potential plate deterioration over time. Therefore, filler plates are made of the same material as the main plates to ensure they can function up to the design life.

Conclusion

Packing plates are essential components in steel structures, serving crucial roles in load distribution, alignment, adjustment, and connection enhancement. Understanding their functions and appropriate usage can help ensure the safety and longevity of any steel structure project.