Detailed defect location
Shows where in the depth and across the section a defect lies.
Foundation Testing
Cross-Hole Analyzer (CHA/CSL)
Cross-hole sonic logging that examines pile and shaft concrete quality between access tubes.
Overview
Access tubes are cast into the pile; a transmitter and receiver are lowered into different tubes and ultrasonic pulse travel time and energy are logged with depth. Defects appear as delays or energy loss, giving a detailed check of concrete integrity across the section.
Cross-hole sonic logging sends ultrasonic pulses between tubes cast into a pile or shaft. Pulse arrival time and energy are recorded at every depth. Slower or weaker signals reveal poor concrete, voids or soft inclusions across the section.
- Ultrasonic logging between access tubes
- Depth-wise record of concrete quality
- Detailed view of defects across the section
- Common for large-diameter bored piles and shafts
Key Benefits
Good for large piles
Reaches the core of large-diameter shafts that surface tests cannot.
Full-depth record
Continuous profiles down the whole pile.
Objective quality evidence
Quantified concrete quality for acceptance.
Where It Is Used
- Large-diameter bored piles
- Diaphragm walls and barrettes
- Bridge pier shafts
- Critical foundations needing full verification
How We Work
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1
Install access tubes
Fix water-filled tubes to the cage before concreting.
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2
Lower the probes
Place transmitter and receiver in a pair of tubes.
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3
Log up the pile
Record signals at regular depth intervals for each tube pair.
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4
Assess results
Review arrival time and energy profiles for anomalies and report.
What You Receive
- Depth profiles for each tube pair
- Defect zones with depth
- Concrete quality assessment
- Test report
Frequently Asked Questions
Do tubes have to be installed in advance?
Yes. They must be attached to the reinforcement cage before the pile is concreted.
How many tubes are needed?
Usually one tube per about 300 mm of pile diameter, arranged around the cage. The project specification governs.
Have an infrastructure testing or monitoring requirement?
Tell us about your project — our engineering team will follow up on scope, instrumentation and approach.