Advantages and disadvantages of both steel structure and grid structure

Steel structure is mainly composed of steel beams, steel columns, steel trusses and other components made of steel and steel plates. Welds, bolts or bolt nails are usually used to connect the components or parts. Because of its light weight and construction, it is widely used in large factories, venues, super high-rise buildings and other fields.

1. Light weight of steel structure

Although the bulk density of steel structure is serious, its single weight is much higher than other building materials, so when the distortion and conditions are the same, the steel structure is lighter than other structures, easy to transport and install, and can be extended to a larger span.

2. Good plasticity and strength of steel With good plasticity, grid engineering generally will not be suddenly destroyed due to accidental overload or local overload. The safety and reliability of the structure are fully guaranteed.
3. Steel is closer to homogeneous and isotropic bodies. The internal structure of steel is relatively uniform, very close to homogeneous and isotropic bodies, and is almost completely elastic within a certain stress range. It is more in line with the actual stress conditions, so the calculation results of steel structures are more in line with the actual stress conditions.
4. Steel structure manufacturing alternative, easy to adopt industrial production, short construction and installation period.

A large number of steel structures are manufactured in specialized metal structure manufacturing plants; high precision. The manufactured components are transported to the site for assembly, bolted, and light in structure, so the construction is convenient and the construction period is short. Finally, the built steel structure can also be disassembled, reinforced or modified.

5. The steel structure has good sealing. The steel structure has better air tightness and water tightness.
6. The steel structure has good heat resistance, but poor fire resistance

Steel is heat-resistant but not high-temperature resistant. With the increase of temperature, the strength decreases. When there is radiant heat around and the temperature is above 150 degrees, shielding measures should be taken. If a fire occurs, when the temperature of the structure reaches more than 500 degrees, it may all collapse suddenly. In order to improve the fire resistance level of the steel structure, it is usually wrapped with concrete or bricks.

7. Steel is easy to rust, and protective measures should be taken. Steel is easy to rust in a short environment, especially in an environment with corrosive media. It must be painted or galvanized, and it should be regularly maintained during use.

The grid structure is usually divided into four categories: the grid structure composed of plane truss system, tetrahedron, triangular pyramid and hexagonal pyramid.

The main steam turbine house roof system of the thermal power plant usually adopts the upright tetrahedron grid. The bottom edge of the tetrahedron that constitutes this grid is parallel or perpendicular to the boundary, and the pyramid is fully spread on the entire grid plane. The upper (lower) chord oscillator of the frame is the tip of the forward (inverted) pyramid, and can also be regarded as the corner point of the bottom edge of the inverted (forward) pyramid, so that the plane projection of the upper and lower chord rods in the same direction just forms a vertical parallel line, which is half the grid spacing. The upper and lower chord grids formed are usually square. When the lengths of the chord rods in the two directions are not equal, a rectangular grid can also be formed.

Advantages and characteristics of the grid structure:

1. Spatial work, simple force transmission path, suitable for large span and large column grid roof structure.
2. Light weight of the structure and good economic indicators. Compared with the flat steel roof truss with the same span, when the span is less than 30m, the steel consumption can be saved by 5~10%; when the span is greater than 30m, it can save 10~20%.
3. Large spatial rigidity, small structural deadweight, and good seismic performance.
4. Proper construction and installation. There are few types of grid rods and sequences, and the size is not large. Transportation, storage, loading and unloading, and assembly are all relatively convenient.
5. The grid has a flexible plane layout and a flat roof system, which is conducive to the installation of suspended ceilings, pipelines and equipment.