Cross-Hole Sonic Logging Test
Cross-hole sonic logging (CSL) is one of several methods
which are employed to assess the integrity of cast-in-situ piles. CSL is an indirect integrity evaluation method which needs interpretation. The testing is
carried out following the guidelines outlined in ASTM-D6760 using the Pile
Dynamics Inc. Cross Hole Analyzer device.
During the construction, closed ended
PVC or steel tubes are installed around the inner perimeter of the steel
reinforcement cage. The transceivers are then simultaneously lowered into a
pair of access tubes. The first probe transmits a high-frequency signal that
travels through the concrete and is detected by the second probe acting as a
receiver. As the sensors move up and down along the foundation's length, the
device records and displays the energy of the received signal and the time it
takes for the signal to travel from emission to arrival as a function of depth.