Steel Structure Inspection

The steel structure has been an important type of structure in today’s construction projects. Because of its lightweight, high strength, and strong deformation capacity, the steel structure has become an ideal structure for many large-scale engineering projects. The use of steel structures in various projects, not only greatly improves the construction efficiency of the project, but also reduces the construction cost. However, because of the characteristics of steel, there are many unavoidable problems, which are accompanied by the wide application of technologies and methods for testing and fixing of steel structures. Although the steel structure material is widely used in construction projects, it also has certain defects, the need for its safety appraisal to ensure the safety of people’s lives and property.

1 Detection of a section thickness of steel structures

The section thickness of steel structure is often affected by the processing accuracy and section corrosion. In particular, corrosion will make the section thinner and the loading force decrease, which will have a great influence on the safety of the whole steel structure. Therefore, it is a very important task to determine the thickness of the steel structure section. At present, the thickness of the section is usually determined by a thickness gauge. The ultrasonic pulse reflection method is used. Ultrasonic waves propagate from one homogeneous medium to another homogeneous medium, reflection occurs, and ultrasonic waves from the probe reach the interfaces, and are reflected to be received by the receiving probe. The thickness of the measured part is calculated using the measured time between the emitted pulse and the received pulse.

2 Determination of coating thickness of steel structure

In steel structure appraisal, good or bad coating will directly affect the solidity of the steel structure. Generally, the thickness of the coating is measured by a magnetic thickness gauge. Magnetic thickness gauge, to adjust the instrument beforehand so that it can work properly. First of all, to determine the measurement range. Then start measuring, measuring first to remove the coating surface dust and oil, to prevent affecting the accuracy, and then use the probe to contact the measured coating. According to the actual situation, first determine the presence or absence of coating, due to the long-term impact of the natural environment, the coating will be broken or even disappear. Because the presence or absence of residual coating is an important boundary of the degree of structural corrosion.

3 Determination of steel structure deflection

Steel structure is generally larger span, measuring the deflection is more difficult, must use a lot of force to tighten the wire, but also requires a certain strength of the wire, to do a good job with the completion of the records and anti-arch or deflection value. Because only to determine these two values to determine the roof frame under the action of the load stress deflection value, at present, China’s steel structure deflection determination has begun to change a large number of level meter, total station: level meter characteristics of high-quality telescope optical system, solid and stable structure of the instrument, high-precision micrometer device, highly sensitive tube level, high-performance compensation device. The total station is characterized as an automated, digital, and three-dimensional coordinate measuring system with automatic distance measurement, angle measurement, calculation and data processing, automatic recording, and transmission functions.

4 Quality Inspection and Assessment of Steel Structures

Steel structures are manufactured with the following defects: deviations in dimensions, non-linearities of members, low-quality structural welding, and riveting. Poor quality of primers and coatings, etc. Due to the existence of these defects and the influence of these defects on each other, the structure as a whole and locally will be subjected to different degrees of damage.