Abstract: With the Wilson- numerical direct integration scheme, a 3D finite element model of the pile-soil system is established for impulse responses at the top of a concrete pipe pile. Some representative features of the calculated wave signals together with their correlation to the measurement points at the top of pile are investigated. It is shown that the three-dimensional effect of wave propagation along the pipe pile head has great influences on the local defect identification. The results are instructive for better evaluation of pile shaft defects as well as for the reasonable arrangement of transducers with the reflected wave testing.

Key words: reinforced concrete pipe pile, local shaft defects, 3D FEM, reflected wave, arrangement of transducers