First, check the base of the LED display column.
There are two main types of substrates and layouts:
1. One is the balanced gravity type, that is, the upper load is mainly balanced by the mass foundation gravity, which is generally a concrete base. This base form is suitable for use when the soil is soft and there is an open construction site.
2. The other is the pile foundation type, which is mainly based on reamed piles. This type of foundation method can be selected when the construction site is limited. When determining the base of the advertising screen, the initial drawings and construction materials must be checked first, and then the base must be excavated when the conditions permit, to find out whether the base method, burial depth, scale and other conditions are consistent with the drawings, and The strength of the LED screen base concrete is sampled and tested. In other on-site surveys, when choosing a balanced gravity-based advertising screen, special attention must be paid to whether the foundation soil is uplifted or loose around the root of the steel column, and the foundation is shaken under the action of wind load. If the surface collapses, it means that the anti-overturning of the base can no longer meet the requirements. There is a danger of collapse under the action of strong wind at any time, and it must be reinforced immediately. Under normal circumstances, this kind of situation is rarely seen with the use of deep pile base advertising screens.
Second, check the material of the column.
1. Check the quality of the connection between the steel column and the foundation.
The advertising screen steel pipe column and the foundation are generally bolted or welded. For bolted connections, check for missing bolts during inspection, and the bolts must not be deformed, slipped or loosened; if there are design drawings, the specifications and models of the bolts must meet the design requirements; the bolts should be rust-proofed. If the corrosion is serious, it must be replaced immediately. The bolts should be fastened firmly and reliably; for high-strength bolts, the number of exposed threads should be 2 to 3 threads, and 10% of the bolt threads should be exposed to 1 or 4 threads; bolts are embedded The depth must meet the requirements of the specification.
2. Inspection of the steel column.
First, the skew of the advertising screen steel column must be measured. The skew of the steel column must not be greater than 1000/H. It must be measured in two directions; the second is the inspection of the steel quality of the advertising screen steel column. The appearance quality inspection of the steel can be divided. For uniformity, are there items such as interlayers, cracks, non-metallic doping, and significant segregation. When there is any doubt about the quality of the steel, samples can be taken from the components to inspect the mechanical properties of the steel and analyze the chemical composition, but the safety of the structural components should be ensured. Finally, check the steel pipe column for corrosion and the quality of the steel structure protective coating. The quality of protective coatings for steel structures shall be tested in accordance with the current relevant national product standards on the quality of coatings.
Third, the inspection of the upper steel frame member system.
At present, there are two forms of connection between the steel column and the upper steel frame member system:
1. One is T-shaped, and its main frame is formed by a T-shaped fixed connection between a steel column and a horizontal main beam on the upper part, and the advertising screen is connected to the T-shaped rigid frame structure through various pendants and diagonal braces.
2. The other is the space truss type. Its main frame is welded by an independent steel column and several parallel horizontal main beams on the upper part. The main beams are connected by horizontal and diagonal supports to form a space truss system. The advertising screen is directly installed on the main frame.
Because the columns of outdoor LED display screens are top-heavy, there will be more or less potential safety hazards after a period of use. The main structure of the LED advertising screen must be inspected and maintained regularly to ensure safety.
