FPrimeC was retained by customer to perform non-destructive evaluation and testing on existing transmission line foundations in Fort MacKay, Alberta. The main objective was to identify the unknown length of existing pile foundations, as well as verifying the integrity of these foundations.
Multi-Technology Approach for Testing Foundations
A multi-technology approach was used for the inspection and condition assessment of piles and deep foundations. A combination of rebound hammer, ground penetrating radar, ultrasonic pulse velocity testing, and low strain pile integrity testing was used to identify potential defects in the pile elements. Furthermore, pile integrity test results were studies to estimate the unknown length (depth) of existing foundations and piles.
Low strain impact integrity test or as commonly known pile integrity test was utilized to evaluate the unknown length (depth) and quality of existing piles. Test results were conclusive for most of piles, however, larger piles require further testing for accurate results. Pile integrity was also used to evaluate the consistency of foundation elements. The test provided a cost-effective and time-saving solution for assessing the piles with access from the pile head.
Ground Penetrating Radar (GPR) was used to identify the reinforcement pattern near to the pile head. grid scanning was performed to accurately map the longitudinal and transverse reinforcement in the pile head. GPR was also effective in locating the embedded anchors in the foundation element deep 400 mm inside the shaft element.
Ultrasonic Pulse Velocity (UPV) was used to evaluate the quality of concrete near to the pile head. It is used to evaluate the average UPV in the concrete, which can be correlated with general quality of concrete mix.