Low Strain Dynamic Test (PIT)
Test reference Standard: ASTM D5882 – Standard Test method for Low Strain Impact Integrity Test
of Deep Foundations
Test reference Standard: ASTM D5882 – Standard Test method for Low Strain Impact Integrity Test
of Deep Foundations
Cross-hole Sonic Logging
Test reference Standard: ASTM D6760 – Standard Test Method for Integrity Testing of Concrete Deep Foundations by Ultra Sonic Crosshole Testing
ABOUT THE TEST
Crosshole Sonic Logging (CSL) is a reliable integrity testing method for deep foundations. This technique involves transmitting and receiving ultrasonic signals between parallel access tubes embedded in a deep foundation element. CSL assesses concrete integrity and homogeneity within the shaft area, identifying potential anomalies and their severity. With no depth restrictions, CSL testing is relatively quick and typically conducted 3-7 days after concrete placement, providing valuable insights into foundation quality.
Sonic logging is also mandated by the Building and Construction Authority (BCA) for pile test schedules of buildings with 10 storeys or more. As part of Non-Destructive Integrity Testing, High strain dynamic test or sonic logging must be conducted on at least 2 piles or 2% of the total number of working piles, whichever is greater.
Table 1 - Joint BCA/IES/ACES/GEOSS circular 2016 - Requirements on ground investigation, load test and quality control test for foundations of building of 10storeys or more
EQUIPMENT AND TECHNOLOGY
The Cross Hole Analyzer (CHAMP-Q) by PDI assesses the quality and uniformity of concrete in drilled shafts, slurry walls, bored and cast-in-situ piles through Crosshole Sonic Logging (CSL) testing. CHAMP-Q enhances efficiency while meeting ASTM D6760 and other standards. During testing, transceivers transmit high-frequency signals through the concrete, with receivers capturing data as the probes are moved along the shaft, allowing full-length analysis by depth and quadrant. Its portable, rugged main unit features a sunlight-readable LCD touchscreen, real-time analysis tools, replaceable battery, and USB ports for quick data transfer. Paired with CHA-W software, users can review six profiles simultaneously, detect defects, evaluate signal strength, and generate customized reports including sonic maps, wave-speed plots, and first arrival time graphs for comprehensive concrete evaluation.