A novel approach is presented to describe the dynamic interaction system of a large-diameter floating pipe pile and surrounding soils, taking the three-dimensional wave effects into account. The corresponding analytical solutions for longitudinal complex impedance are obtained and subsequently validated via comparisons with existing solutions. Comparative analyses are also performed to illustrate the difference between the present and previous solutions, concerning the wave propagation effect in the radial direction on the longitudinal dynamic vibration of pile shaft. Furthermore, the effects of Poisson's ratio and visco-elastic support beneath the pile toe, on the longitudinal dynamic vibration of pile shaft, are investigated. It is indicated that the presented approach and corresponding solutions provide a more wideranging application for longitudinal vibration analysis of a largediameter floating pipe pile, which can also be reduced to analyze the longitudinal vibration problems of large-diameter floating solid pile and fixed-end pipe pile.

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This article proposes a new analytical model for the low-strain integrity detection of a pipe pile embedded in a viscoelastic soil layer with radial inhomogeneity by extending Novak's plane-strain model and transfer method of complex stiffness to consider viscous-type damping. The analytical solutions for the complex impedance, the velocity admittance and the reflected wave signal of velocity at the pile head are also derived. Extensive parametric analyses are further conducted to investigate the effects of the disturbance degree and the disturbance range of surrounding soil due to construction operation on the velocity admittance and the reflected wave signal of velocity at the pile head. It is demonstrated that the proposed model and the obtained solutions can provide extensive scope of application, compared with the relevant existing solutions.

Based on the theory of wave propagation in three-dimensional (3D) continuum, a new analytical approach for the longitudinal vibration characteristics of a floating pile in layered soils with radial heterogeneity is developed by employing a viscous-type damping model. Firstly, an analytical solution for the longitudinal complex impedance at the pile head is deduced by employing the Laplace transform and complex stiffness technique with the compatibility conditions of the pile and radially inhomogeneous surrounding soil. Secondly, a semi-analytical solution in the time domain is further acquired by using the inverse Fourier transform method. Furthermore, the corresponding analytical solutions are validated through contrasts with previous solutions. Finally, parametric analyses are underway to investigate the effect of radial heterogeneity of surrounding soils on longitudinal vibration characteristics of floating piles. It is indicated that the proposed approach and corresponding solutions can provide a more wide-ranging application than the simple harmonic vibration for longitudinal vibration analysis of a floating pile in soils.