Sonic Echo/Impulse Response (SE/IR)
ACER’s Foundation Mapping and Pile Integrity Testing scope of work includes Non Destructive Testing (NDT) using ground penetrating radar (GPR), Sonic Echo/Impulse Response (SE/IR) testing, and rebar location equipment to determine the dimensions of the existing tower foundations, and arrangement and sizes of steel reinforcement to assist with the design of appropriate structural upgrades that may be required to improve the foundation. In order to determine the depth and integrity of the support foundation, Acer conducts Non-Destructive Testing (NDT) utilizing an Olson Instruments NDE 360 System for Sonic Echo/Impulse Response (SE/IR) testing. Ground Penetrating Radar (GPR) and a Rebar Locator is used to determine rebar location depth and diameter, when accessible.
The Sonic Echo (SE) test method is a low strain integrity test conducted from the top of the shaft as shown in the image below. The test involves hitting the foundation top with the hammer to generate energy that travels to the bottom of the foundation. The wave reflects off irregularities (cracks, necks, bulbs, soil intrusions, voids, etc.) and/or the bottom of the foundation and travels back along the foundation to the top. The receiver measures the vibration response of the foundation to each impact. The signal analyzer processes and displays the hammer and receiver outputs. Foundation length and integrity of concrete are evaluated by identifying and analyzing the arrival times, direction, and amplitude of reflections measured by the receivers in time. The Impulse Response (IR) test method is also an echo test and uses the same test equipment as the SE method. The test procedures are similar to the SE test procedures, but the data processing is different. The IR method involves frequency domain data processing. In this method the vibration responses of the foundation are measured by the receivers are processed to determine foundation length and integrity.
Additional Geophysics & Non-Destructive Testing Services Provided by ACER:
Ground Penetrating Radar
Tower Foundation Mapping