Stress paths measured around a cyclically loaded pile in a calibration chamber

Poulos (1989) presented laboratory model tests to demonstrate that cyclic shaft friction degradation depends on cyclic displacement amplitude, the number of cycles, the soil type, and the pile type. Chin & Poulos (1996) reported further displacement-controlled cyclic tests on model piles jacked into dry calcareous sand. The most significant shaft degradation was observed when the cyclic displacement amplitude led to the static shaft capacity being fully mobilized.