Key points for the design of large-span grid structures

    Long-span grid structures, with their high rigidity, strong stability, and ease of construction, have become a core choice for modern large-scale buildings. As a leading spatial structure service provider in the industry, LF-BJMB consistently adheres to the design philosophy of “Safety, Efficiency, Innovation.” From joint details to overall layouts, we provide scientifically reliable, customized solutions for every project. Today, let’s explore the key design considerations for long-span grid structures.
    (1) Inter-column Bracing:
    Inter-column bracing is crucial for the overall stability of the grid shell. For typical single-layer double-slope roofs, two diagonal braces are usually installed. Each brace consists of two end anchor plates, which should connect to the main beams. For multi-layer or high-rise roof panels, the number of braces can be increased appropriately, but care must be taken to avoid concentrated forces. When brace lengths exceed 4m, horizontal tie rods should be installed at intermediate points. When using multiple two-way tension rods, double or multiple rows are recommended.

(2) Roof Purlins:

To ensure sufficient strength and prevent brittle fracture, stiffening ribs are typically added to purlins. These ribs can be made of structural steel, steel plates, or angle steel. Spacing between ribs should not be excessive and must not exceed 2m. Additionally, base trays should be installed under heavily stressed purlins as needed.  

(3) Cantilevered Eaves:

Cantilevered eaves are innovative high-altitude decorative components primarily used in commercial centers, hotels, and similar buildings. To meet diverse aesthetic requirements, perforations can be made in metal panels and filled with fiberglass. Varying metal panel thicknesses can also achieve different forms while enhancing wind resistance.  

(4) Supports:

For supports, besides conventional two-way prestressed concrete short-leg shear walls, one-way prestressed concrete short-leg shear walls can be utilized. These walls can withstand both vertical and lateral pressure.  

(5) Deformation:

In long-span spatial grids, significant relative displacement between units necessitates considering deflection caused by temperature variations. Typically, the grid is divided into zones with specific widths. Expansion gaps must also be reserved within the grid to accommodate temperature changes. Additionally, localized shrinkage deformation due to material contraction should be considered.