Evaluation of Cyclic Model Tests on Anchor Piles in Clay

Abstract

The response of anchor piles in clay subjected to cyclic loading was investigated in a series of tests on small size model piles, 40 cm long and 1.9 cm in diameter, jacked into a reconstituted and normally consolidated clay. Evaluation of the test results focusses upon the degradation of cyclic pile stiffness, the accumulation of permanent displacements, the degradation of cyclic pullout capacity, as well as the short time effects of cyclic loading on the post-cyclic static pile response. The cyclic response of the model piles was correlated to that of the surrounding soil elements, observed in a series of undrained cyclic triaxial tests. In addition, the influence of the small scale of the model piles on the experimental results was assessed through comparison to similar data from large scale model and field tests reported in the literature. Cyclic load and displacement magnitudes, number of cycles and cyclic preshearing were identified as the main factors which control the pile response. The small size of the pile influences the experimental results at low cyclic loading intensities when radial drainage leads to partially drained conditions during cyclic loading.