Abstract：The longitudinal dynamic impedance at the head of the static drill rooted nodular pile is investigated based on the three-dimensional axisymmetric model in which only the vertical displacement of the surrounding soil is considered regarding the complexity of the pile body structure and the pile-soil contact conditions. Firstly，the soil reaction acting on the pile tip is simulated with the fictitious soil pile model，and the pile-soil system is divided into a number of segments according to the stratification of the surrounding soil and the distribution of the nodes of the pile. Meanwhile，the surrounding soil is discretized into several annular vertical zones to consider its radial inhomogeneity. Then，the analytical solution for the dynamic response at the pile head in the frequency domain is derived by means of Laplace transform and the impedance function transfer method. The degenerated solution is compared with other solution to verify its reliability. Finally，the influence of pile-soil parameters of the nodes of pile，the surrounding cement-treated soil and the pile tip soil on the dynamic impedance at pile head is investigated within the low frequency domain concerned in the design of dynamic foundation.
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2017, Vol. 36 
