The impact of defects type and location on the integrity test results of RC piles in sand

Abstract

Abstract This research investigates the impact of pile defects on the prediction accuracy of pile toe during the low-strain integrity testing (LSIT). It assesses the conditions of concrete piles, especially piles with defects that are often difficult to identify through traditional investigation. The developed 3D FEM model in ABAQUS 2024 is validated using field data from projects in Egypt. The methodology includes this developing model and a parametric study of 90 cases, including intact and defective piles. The considered parameters are defect type, defect location, pile slenderness ratio and relative density of sand. The proposed model studied the effect of these parameters on the detection of the pile toe. It also investigates their effects on the reflectogram magnitude at the pile toe and at the defect location. This research describes the waveform response to the studied parameters and presents the effects of defects on LSIT results for piles. The FEM results showed that wave behavior depends on pile geometry, soil stiffness, defect location, and defect type. Defect type and location along the pile affect the pile toe detection in terms of the arrival time. An approximate linear relationship (R 2 = 0.9983) is observed between the normalized defect response and the defect location along the pile. This indicates a nearly 53% reduction, as the defect is located near the pile toe. The proposed equation provides a practical method for estimating defect severity and its size as a function of relative defect magnitude and defect location in the pile.