Dynamic response of vertical vibration of pipe piles in soils with radial inhomogeneousity and viscous damping considering vertical wave effect

Based on the three-dimensional axisymmetric model for the surrounding soils with viscous damping, a simplified mechanical model of vertical vibration for the dynamic interaction of pipe piles embedded in radially inhomogeneous viscoelastic soils is proposed accounting for the vertical wave effect of surrounding soils. The complex stiffness at the interfaces between soils and pipe piles is derived by using the Laplace transform and complex stiffness transfer method. And the analytical solutions for dynamic impedance at the pile head are obtained by using the pile-soil compatibility of piles and radially inhomogeneous surrounding soils. Furthermore, the obtained analytical solution for dynamic impedance at the pile head is also reduced to verify its validity by the comparison with the existing solutions. Finally, an extensive parametric analysis is also conducted to investigate the effects of the pile length, inner diameter, construction disturbance intensity and range on the dynamic impedance at the pile head, and it can provide reference for engineering practice.