Sonic Logging Pipe

Sonic logging pipe, also known as sonic logging pipe for cast-in-place concrete piles, are pipe systems pre-embedded within the pile body during concrete pile construction. They are specialized channels for ultrasonic transmission testing of pile foundation quality.

The core working principle is as follows: Before the concrete is poured, the sonic logging pipe are installed vertically parallel to the reinforcing cage. During testing, ultrasonic transmitting and receiving probes are placed in different sonic logging pipe. By analyzing changes in parameters such as sound time, frequency, and amplitude attenuation during sound wave propagation in the concrete, the location, extent, and severity of pile defects are determined.

Sonic logging pipe are typically composed of several pipe sections connected by joints. Both the lower and upper ends are sealed with caps, and the pipe are filled with clean water as the ultrasonic coupling medium. The application of sonic logging pipe is unaffected by pile diameter, pile length, or geological conditions. The equipment is portable and can be used in various complex terrain conditions, including mountainous areas.

Material: 

The materials of sonic logging pipe are mainly divided into the following categories based on the usage environment and cost requirements:

Q235B is the most commonly used material for sonic logging pipe. For humid environments, 304 stainless steel is recommended for rust prevention; for ordinary environments, Q235B carbon steel can be used to reduce costs.

Connection Methods: There are four main connection methods for sonic logging pipes, each suitable for different scenarios.

Features of Sonic Logging Pipe

Sonic logging pipe is a pipe that can measure pile foundation engineering through sound. It is usually composed of steel pipes and pile heads, and has good durability, earthquake resistance and impact resistance. The characteristics of the sonic logging pipe are mainly manifested in the following aspects:
1. The sonic logging pipe has a long service life. Due to its special structural design, the acoustic tube can withstand various weather conditions and environmental factors, so the acoustic tube is generally used for life.
2. High sound wave conductivity. Due to the unique material manufacturing process and high-strength steel plates used in the sonic logging pipe, they can effectively transmit energy to the formation.
3. Good impedance matching. There are generally more than three layers of different types of pipeline layers inside the sonic logging pipe, so that the acoustic tube can be impedance-matched with the surrounding soil or buildings.
4. Reusable. Sonic logging pipe can be recycled and reused to reduce environmental pollution.

Applications of Sonic Logging Pipe
For acoustic measurements, sonic logging pipe can be used to monitor various sound sources and record their duration and intensity. Sonic logging pipe can also be used to detect various sounds, including the frequency and intensity of the sound. In addition, sonic logging pipe can also be used to detect the bearing of a specific sound source for precise localization. In terms of special industrial needs, the sonic logging pipe can also be used to detect the sound in some special industrial applications, such as aircraft engine noise, train engine noise, etc.
1: For acoustic measurements
The use of sonic logging pipe for acoustic measurements refers to the measurement of sound, usually using acoustic instruments. The main purpose of acoustic measurements is to determine various characteristics of audio signals such as frequency, amplitude and phase. These properties can be used to measure the quality of sound, assess the impact of sound, or study the propagation of sound in specific situations.
2: Used as a testing instrument
Sonic logging pipe can be used as testing instruments and are usually installed in acoustic laboratories or industrial locations.
3: Special industrial needs
Sonic logging pipe can be used for special industrial needs, such as acoustic measurement in high-sound environments. Sonic logging pipe can also be used as detection instruments that can help detect high sound levels.

Sonic logging pipe are instruments used to measure sound intensity and can be used to measure various types of sound. It has high accuracy and can help people conduct various acoustic studies.

Sonic Logging Pipe have obvious advantages in the measurement of soil density and soil layer conditions, but they need to pay special attention to details and strictly abide by the standard specifications when using them. The following are the national standards of some countries:

Chinese standard:
GB/T 31438-2015 "Steel thin-walled sonic-testing tubes for concrete bored piles".

American standard:
MIL-STD-1691 This standard was issued by the US Department of Defense to ensure the accuracy and reliability of underwater acoustic equipment for military applications. It contains a series of tests and procedures designed to ensure the performance of underwater acoustic equipment in accordance with the requirements of military and marine surveys.

Japanese standard:
JIS C 6560-1:2004: This standard is part of the Japanese Industrial Standards (JIS), which specifies the definition and naming methods of underwater acoustic sensors (including sonic logging pipe).
JIS C 6560-2:2006: This standard specifies the measurement method for underwater acoustic sensors (including sonic logging pipe).
JIS C 6560-3:2008: This standard specifies the performance and general requirements that should be specified in the data sheet for underwater acoustic sensors (including sonic logging pipe).
JIS C 6560-4:2010: This standard specifies the calibration method of underwater acoustic sensors (including sonic logging pipe).

This standard specifies the product type, size and quality, technical requirements, test methods, inspection rules, packaging, marking, transportation and storage of steel thin-wall acoustic pipes for concrete pouring piles.  

The acoustic tube implements the national GB/T 31438-2015 standard to meet the national environmental protection requirements

Common Wall Thicknesses
Sonic logging pipes come in a variety of wall thicknesses, ranging from thin to thick:
0.9, 1.2, 1.4, 1.5, 1.7, 2.0, 2.2, 2.5, 3.0, 3.25, 3.5 mm

Common specifications used in engineering projects include:
Φ50×1.2mm, Φ50×2.5mm
Φ53×2.0mm
Φ54×1.5mm, Φ54×3mm
Φ57×1.5mm, Φ57×3mm

Length
The typical length of a single section of sonic logging pipe is 6m, 9m, or 12m. The allowable length deviation is generally ±25mm～±50mm.

Outer diameter: 50mm 51mm 53mm 57mm etc.
Thickness: 0.8-3.75mm
Length: 3-12m

Dimensions, wall thickness error range: outer diameter ±1.0%, wall thickness ±5%.