Types and Specifications of Sonic Logging Pipes
(1) Diverse Types
Crimp-type Sonic Logging Pipes: This type of sonic logging pipe has a unique connection method. A dedicated hydraulic tool is used to squeeze the connection part of the pipe body, causing the pipe material to shrink and deform, thereby achieving a reliable connection. Its advantages include fast connection speed and good sealing performance, which can effectively prevent grout leakage and other issues, making it widely used in practical engineering.
Screw-type Sonic Logging Pipes: They adopt a spiral connection method, utilizing the tight fit of threads to connect pipe bodies. This type of sonic logging pipe offers high connection strength, performing well in engineering projects with strict requirements for connection stability. Additionally, its installation process is relatively simple and easy to operate.
Sleeve-type Sonic Logging Pipes: Two sonic logging pipes are connected using a sleeve. The interface between the sleeve and the pipe body is usually sealed by welding or sealant to ensure connection tightness and firmness. Sleeve-type sonic logging pipes have advantages in large-diameter pile foundation projects, as they can withstand large construction stresses.
Socket-type Pile Sonic Logging Pipes: They rely on the fit between sockets and spigots for connection. During installation, the spigot end is inserted into the socket end and then fixed using specific methods. This connection method facilitates construction operations to a certain extent while ensuring connection reliability.
Flange-type Sonic Logging Pipes: They are connected using flange plates and bolts, featuring firm connection and excellent sealing performance. They are suitable for special engineering scenarios with extremely high requirements for the connection strength and sealing performance of sonic logging pipes.

(2) Precise Specification Setting
The diameter of sonic logging pipes is usually determined based on actual engineering needs and the requirements of inspection equipment. Generally, a diameter approximately 10mm larger than that of the radial transducer is sufficient to meet inspection needs, with common specifications ranging from 50mm to 60mm in inner diameter.
In terms of pipe wall thickness, although it has little impact on the sound transmission rate, comprehensive consideration of steel consumption savings and construction strength requirements shows that thinner pipe walls are more economical under the premise of withstanding the lateral pressure of freshly poured concrete.
In terms of length, sonic logging pipes typically have a standard length of 6 meters. They can be flexibly adjusted by adding intermediate pipes and joint pipes according to the depth requirements of the pile foundation. For example, in the construction of bored cast-in-place piles for deep bridges, wharves, and high-rise buildings, the number and layout of embedded sonic logging pipes must be determined based on the pile diameter:
For piles with a diameter not exceeding 0.8m, two pipes are arranged along the diameter;
For piles with a diameter greater than 0.8m but not exceeding 1.6m, three pipes are arranged in an equilateral triangle;
For piles with a diameter greater than 1.6m, four pipes are arranged in a square.