Installation Key Points and Precautions for Sonic Logging Pipes
(1) Pre-installation Preparation
Before installing sonic logging pipes, strict quality inspection of the pipes is required, including:
Visual inspection (checking for cracks, holes, deformation, and other defects);
Dimensional measurement (ensuring the pipe diameter, wall thickness, etc., meet design requirements);
Sound transmission performance testing.

At the same time, the position and fixing method of sonic logging pipes in the reinforcement cage should be accurately determined in accordance with the engineering design drawings. Generally, sonic logging pipes can be directly fixed to the inner side of the reinforcement cage using welding or binding methods. However, it is necessary to ensure that the pipes remain basically parallel to each other. If the inspection results require evaluating the concrete strength at each measuring point, the non-parallelism should be strictly controlled below 1‰. In addition, the reinforcement cage should be prevented from twisting when being lowered into the pile hole to avoid affecting the installation quality of the sonic logging pipes.
(2) Detailed Installation Process
Sectional Installation and Connection: Sonic logging pipes are usually installed in sections along with the reinforcement cage, and the connection quality of the joints between sections is crucial. Common joint solutions include reverse-thread sleeve interfaces, sleeve welding, and corrugated pipe sockets. Regardless of the joint method adopted, it must be ensured that no grout leaks under high hydrostatic pressure, and the inner wall of the interface should remain smooth without protrusions such as welding slag or burrs, which could hinder the free movement of the probe.
For example:
When using reverse-thread sleeve interfaces, the machining accuracy and fitting tightness of the threads should be ensured;
When using sleeve welding, the welding quality must be guaranteed to avoid insufficient welding or missing welding;
When using corrugated pipe sockets, the two ends of the socket pipe should be wrapped and sealed with tape to prevent mud infiltration.
Bottom and Top Treatment: The bottom of the sonic logging pipe should be strictly sealed, which can be achieved by welding a sealing plate or using special sealing accessories to prevent grout from entering during concrete pouring. After installation, the top of the pipe should be blocked with a wooden plug to prevent foreign objects from falling in during concrete pouring, which could cause pipeline blockage. Meanwhile, during the construction process, attention should be paid to protecting the sonic logging pipes to avoid damage caused by external forces such as collision or extrusion.
(3) Installation Quality Control
After the installation is completed, a comprehensive inspection of the installation quality of the sonic logging pipes is required:
First, check whether the sonic logging pipes are firmly fixed and free from loosening;
Second, check the sealing performance of the sonic logging pipes through water injection tests to ensure no grout leakage;
Finally, use professional inspection equipment to test the verticality of the sonic logging pipes to ensure they are vertically installed without inclination.
If problems are found during the inspection, timely rectification should be carried out to ensure that the installation quality of the sonic logging pipes meets the engineering requirements.