During the construction of building structures, old buildings, high-risk buildings or buildings with hidden quality defects, the safety and reliability of their structures need to be inspected and identified in accordance with national regulations. The so-called building structure inspection and appraisal is to inspect the whole and part of the building structure. The inspection shall be carried out in strict accordance with the relevant standards and specifications, and the inspection results shall be verified with the design drawings and specifications. If the verification result is unqualified, a qualified design unit shall be required to issue a reinforcement plan, and the on-site construction reinforcement shall be done according to the requirements of the reinforcement plan. In this regard, it is particularly important to discuss relevant structural building inspection and reinforcement construction technology methods to guide how to more effectively and economically adopt adaptive building structure inspection methods and reinforcement technologies.

1 Building structure inspection technology

In the process of building structure detection, it is necessary to analyze and adopt suitable detection technology according to the specific situation of each detection structure type. In the specific work, it is necessary to test according to the material mechanical properties of the building, the structural measures of the building structure, and the geometric measures of the building structure. With the massive increase in the scale of construction in my country, various defects are prone to occur during the construction process, coupled with the concealment of quality defects themselves, so it is very important to strengthen the quality management work, and it is also necessary to do a good job in quality inspection. In order to better strengthen the construction quality, it is of great significance to do a good job in quality inspection technology

1.1 Core drilling technology

Large-diameter bored piles generally have higher design loads, and it is more difficult to use static test piles, and the overall benefits are poor. Therefore, it is necessary to use a geological drilling rig to obtain core samples in the length direction on the structure and walls, and use the observation and testing of the core samples to judge the construction quality. This method can only reflect the quality of a small part of the concrete within the drilling range, and at the same time, the equipment cost is high, the application of the detection technology is cumbersome, and the overall benefit is poor. It cannot be applied to large-area inspection tasks, but can only be applied to sampling inspection, generally 3% to 5% of the total volume and non-destructive testing requirements.

1.2 Vibration detection technology

Vibration monitoring technology is also called dynamic measurement technology. It is mainly to apply an exciting force on one side of the structure in various ways to promote a vibration between the structure and the structure system. At the same time, a stress wave can be formed in the structure, and the quality analysis can be realized by the fluctuation and the parameter change of the fluctuation, and the overall bearing capacity can be judged. This method is more commonly used such as percussion, hammering, steady-state excitation mechanical impedance, transient excitation mechanical impedance, and hydroelectric effects.

1.3 Ultrasonic pulse inspection

The application of this method in structural quality inspection is mainly in the detection of defects. Before the structural concrete is poured, multiple inspection channels are embedded in parallel in the length direction, and used as the main channel for ultrasonic testing and receiving transducers. During the inspection process, the probe moves in the middle of the two pipes, gradually according to different depths. The parameters of the ultrasonic pulse passing through the concrete on the cross section were tested, and the concrete quality of different sections was analyzed according to the principle of defects in the ultrasonic inspection process.

1.4 Ray technology

This technical method mainly uses the attenuation, absorption and scattering of radioactive isotope radiation in concrete to achieve quality detection. When the rays pass through the concrete, the strength of the rays will change differently due to the different quality of the concrete and the influence of the defects. With the help of the degree of change, the structure quality can be judged.

2 Reinforcement construction technology

2.1 Concrete reinforcement method

At present, there are many types of technologies that can be used for defect treatment, such as in-situ composite pile, pile connection, bored high-pressure grouting and other technologies. For the in-situ composite pile technology, if the problem of broken piles has been discovered during the construction process, then the in-situ composite pile construction technology can be used to deal with it. Thorough cleaning of defective broken piles and pouring new grout into the original position of broken piles can effectively deal with the problem, and there are also high quality benefits in terms of defect repair. However, because of the long construction period, high cost and difficulty of operation, the promotion effect is not very satisfactory.

Secondly, for the pile connection method, the pile connection method is mainly to perform acoustic measurement processing on the pile concrete. While judging the location and extent of the broken pile, if the detection result shows the position of the broken pile on the surface, the pile connection method can be used for processing. At the same time of cleaning, it is necessary to remove the defective parts of the pile body, clean up the mud caused by the broken pile and the incomplete concrete in the pile body. At the same time, the pile surface shall be cleaned up, and the defective pile body shall be bound to the template and steel bars. , To promote the effective connection of the connecting pile and the cast-in-place pile. The last is the drilling and high-pressure grouting technology. The drilling and high-pressure grouting technology is mainly for projects where the length of the pile is insufficient, the bottom of the pile is too much sediment, or the concrete has segregation and honeycomb phenomenon. For the defects of insufficient pile length and bottom sediment, it is necessary to clean up the working surface in time, adopt pile drilling to ensure the balance of the pile body at the same time, and continuously adjust while drilling to avoid tilting due to drilling operations The resulting construction problems. After cleaning the borehole, clean up the sediment in time during the drilling process, carefully measure and calculate the amount of concrete used for pouring, and select concrete with a higher number than the original one. Pay attention to the wall of the borehole during high-pressure pouring. Sealing treatment to prevent excessive mud outflow. For the segregation and honeycomb phenomenon of the pile concrete, it is necessary to carry out a water pressure test on the pile before the configuration and high pressure pouring, and take targeted treatment measures according to the test results. If there are defects, you can use pile connection or drilling After high-pressure grouting.

2.2 Steel structure reinforcement method

Compared with concrete structure, the reinforcement method of steel structure is much simpler and faster, which is mainly processed by welding. The principle is to use the principles of reducing the load and changing the calculation graph, strengthening the cross-sectional area of the original structural member, the connection strength, and avoiding crack propagation. According to the scope of damage, it can be divided into two types: comprehensive reinforcement and partial reinforcement. Changing the calculation area of the structure is the most important reinforcement. It is mainly based on the idea of changing the load distribution direction, the way of force transmission and the boundary conditions, and the way to improve the additional rods to achieve the improvement of the stiffness of the damaged structure and members. During operation, the effect of reinforcement treatment can be achieved by means of lifting support rods, tie rods, and changing the internal force of the structure and the interface of the components.

There is also a reinforcement method using outer steel for construction. This construction method is mainly to add a layer of steel structure on the outside, which can improve the strength of the overall structure, but the cost is relatively high, and it can only be applied to some core structures.

3 Conclusion

The use of scientific and accurate detection technology for the construction of buildings, old buildings, high-risk buildings, or buildings with hidden quality defects is the key to ensuring their safety, reliability and practicability. Reinforcement construction technology is an effective way to improve the structural stability of buildings with quality defects and hidden safety hazards and reduce the risk of component damage. However, with the continuous changes of building problems, reinforcement construction technology also needs continuous innovation and continuous improvement of the overall level of reinforcement and repair, so as to promote the high safety of buildings and promote the sustainable development of social economy.