Crosshole Sonic Logging

Olson's Best Selling Nondestructive Testing System to Test Newly Placed Shaft Foundations

The Crosshole Sonic Logging system is the most accurate and reliable technique for assessing the integrity of deep foundation elements constructed on-site from concrete or grout. The system is designed for Quality Assurance (QA) testing of newly placed critical drilled shaft foundations and auger cast piles, but can also be applied to slurry walls, mat foundations, and mass concrete pours. Using water-filled access tubes, CSL testing provides assurance that the foundation concrete is sound with no defects such as soil intrusions, necking, sand lenses, voids, etc.

Where defects exist, the extent, nature, depth, and approximate lateral location of the defects can be determined with the Crosshole Sonic Logging method and further refined with Tomographic Imaging Software, which is sold by Olson Instruments. (Note: Optional Tomo software is available for the CSL, UPV, and CS/DS add-on test methods)

A variation of the CSL method, called Single-Hole Sonic Logging (SSL) can also be used on smaller diameter drilled mini-piles and auger cast piles. The Single-Hole Sonic Logging method is used in cases where only a single access tube can be placed in a deep foundation, and tests the concrete quality in the region around the single access tube.

Data Platform Required, Sold Separately

Freedom Data PC
Materials Tested:
  • Drilled Shafts (Bored Piles)
  • Diaphragm Walls
  • Slurry Walls
  • Mat Foundations& Seal Footings
  • Mass Concrete Pours
  • Pressure Injected Footings
  • Auger Cast Concrete Piles
  • Water Saturated Media
  • Cemented Radioactive Wastes
Test For:
  • Cracks
  • Soil/Water Intrusions
  • Uncured or Weak Concrete
  • Voids
  • Necking
  • Sand Lenses
Meets ASTM:
  • ASTM D6760-08
Meets ACI:
  • ACI 228.2R

Key Features & Specifications

System design allows for fast and accurate field measurements, plastic Test Block to check system operation beforehand Typical testing rate: 3-4 minutes per test tube pair (depending on experience of user and shaft length)
Tests up to 20 ft (6.5m) through concrete, sensitive enough to detect small defects Meets ASTM and RILEM standards
Maximum pull rate: ~3 feet/second (1.0 m/s) in “Normal” position, ~ 0.75 ft/s (0.3 m/s) in “High” position Depth Resolution: ~2.2 inches (5.6 cm) in “Normal”, 0.55 inches (1.4 cm) in “High”
Hydrophones (42 KHz) are interchangeable as both source and receiver Hydrophone Transducer Type: Piezoelectric with Center Frequency of 42 kHz
Real-time waveform and log results display while testing, alternate CSL log display formats available at a key stroke Advanced user-tunable automatic first signal arrival picking algorithm
Software allows for Automatic Log and optional Report Generation in Microsoft Word (tailored to customer’s requirements) Single hole and Crosshole Capable
Smart logging algorithm that graphically shows already logged tube pairs as well as the next tube pair to be logged Optional Tomographic Imaging Software available

Hands-on training is available for all of our NDE test methods at our Wheat Ridge, Colorado (USA) location, which is a suburb located approximately 15 minutes northwest of downtown Denver. Training may be available at your location by one of our agents/engineers upon special arrangement.


Save money! Contact Olson when adding on to an existing system, or purchasing multiple systems as some of the components are common to other test methods.

For complete details about any of our products, call our toll free number at 1-888-423-1214 or email Olson Instruments: