Classification of formal structures of steel grid structures

Classification of formal structures of steel grid structures

2. Classification of steel grid structures, plate grid structures are divided into three categories:

1. Composed of a planar truss system, there are four forms of grid structures: two-way orthogonal orthogonal grid structure, two-way orthogonal diagonal grid structure, two-way diagonal diagonal grid structure, and three-dimensional grid structure;

2. It is composed of quadrangular pyramidal elements, and has five forms: positive Square pyramid grid, positive Square pyramid grid, oblique Square pyramid grid, chessboard Square pyramid grid and star Square pyramid grid;

3. Consisting of triangular cone units, there are three forms of triangular cone grid, evacuated triangular cone grid, and honeycomb triangular cone grid.

The shell type grid structure is mainly divided into cylindrical shell type grid, spherical shell type grid, and hyperbolic parabolic shell type grid according to the shell surface form.

The grid structure is divided into steel grid, reinforced concrete grid, and composite grid composed of steel and reinforced concrete according to the materials used, with steel grid being the most commonly used.

Installation method of steel grid structure

Since the emergence of steel grid structure, it has been popular for its efficient load-bearing performance, novel and beautiful form, and fast and convenient construction. In sports stadiums, exhibition centers, cultural facilities, transportation hubs, and even industrial factories that require large spans and spaces, spatial structures can be seen everywhere. It can be used as the roof of gymnasium, theater, exhibition hall, waiting hall, stadium stand canopy, Hangar, two-way large column steel grid structure and workshop. Application in industrial buildings such as dry coal sheds, storage sheds, stacking plants, uniform material warehouses, auxiliary material warehouses, and clinker warehouses.

The installation methods of steel grid structures are divided into two categories: one is the overall lifting method, the overall lifting method, and the overall lifting method assembled on the ground; Another type is the method of bulk assembly, strip and block assembly, and high-altitude sliding assembly for high-altitude positioning.

Force analysis of grid structure

The grid structure is divided into single-layer grid, double-layer grid, and three-layer grid according to the number of layers; According to Gaussian curvature, it can be divided into grids with zero Gaussian curvature, grids with positive Gaussian curvature and grids with negative Gaussian curvature; Divided into cylindrical grid, spherical grid, double-sided parabolic grid, and complex curved grid according to the surface shape.

In terms of stress on the grid structure: when the members are in tension, the force transmission route is tension - steel pipe - cone head or sealing plate - bolt - steel ball; At this point, the sleeve is not under force. When the rod is under pressure, its force transmission route is pressure plate steel plate cone head or sealing plate sleeve steel ball. At this point, the bolt is not under force, and the pressure is transmitted by the contact surface between the parts. The sealing plate and cone head of the grid mainly serve to connect steel pipes and bolts, bearing the tension and pressure transmitted by the members. When the pipe diameter of the rod is greater than or equal to 76mm, it is advisable to use a conical head connection; When the diameter of the rod is less than 76mm, a sealing plate can be used for connection.

According to the analysis of some grid structures by the general method of vibration mode Chemical decomposition, the seismic internal force and displacement of the grid structures are not significant under the vertical seismic action in areas with seismic fortification intensity of 6 or 7 degrees, so the vertical seismic checking calculation may not be carried out. In areas with seismic fortification intensity of 8 or 9 degrees, grid structures should undergo vertical seismic and horizontal verification calculations.