Sonic Logging Tubes (Acoustic Tubes) 

 Purpose: Sonic logging tubes are preinstalled steel or PVC pipes embedded vertically in concrete deep foundations (e.g., bored piles, diaphragm walls, or barrettes) to facilitate CrossHole Sonic Logging (CSL) or Ultrasonic Tomography Testing. This nondestructive testing method assesses concrete integrity, detects defects (e.g., voids, soil inclusions, necking), and verifies foundation quality.

Key Features & Specifications:
 1. Material:
 Galvanized steel (common) or highstrength PVC.
 Corrosionresistant, watertight, and pressurerated.
 2. Installation:
 Tubes are fixed to reinforcement cages before concrete pouring.
 Arranged in parallel pairs/triads (typical spacing: 1–1.5m).
 Must extend full pile depth with sealed bottom ends.
 3. Testing Process:
 Sensors (transmitter/receiver) traverse tubes filled with water.
 Ultrasonic waves measure wave velocity/attenuation between tubes.
 Anomalies indicate potential defects in concrete.
 4. Standards Compliance:
 ASTM D6760 / AASHTO T 338 (Int'l)
 GB/T 314382015 / JGJ 1062014 (China)
 5. Diameter: Typically 50–60mm (internal).

Applications:
 Critical for highrise buildings, bridges, offshore platforms, and seismic zones.
 Ensures structural safety and compliance with engineering design.

Advantages:
 Highprecision defect imaging.
 No structural damage during testing.
 Costeffective quality assurance for deep foundations.

Key Terminology:
 CrossHole Sonic Logging (CSL): 跨孔声波透射法
 Pile Integrity Testing (PIT): 基桩完整性检测
 Concrete Defect Imaging: 混凝土缺陷成像
 NonDestructive Testing (NDT): 无损检测

This introduction covers technical essentials while aligning with global engineering standards. For specifications, include material grade, wall thickness, joint type (threaded/sleeved), and pressuretest requirements.