To investigate the effect of construction disturbance on vertical vibration characteristics of pipe pile

a simplified mechanical model of vertical vibration for pipe pile embedded in radially inhomogeneous soil was proposed by employing the viscous damping model and considering pipe pile as uniform cross-section and elasticity based on the plane stain model of annular complex stiffness transfer. Firstly

based on Laplace and complex stiffness transfer method

the composite stiffness of pile-soil interface was derived. Secondly

the frequency domain analytical solution of pile head dynamic impedance was obtained by using the compatibility condition. Finally

effects of the slenderness ratio of pile

the inner and outer diameters of pile

the elastic modulus of pile

the viscous coefficient of soil

and the construction disturbance intensity and range on the complex impedance at the pile head were analyzed. The results showed that the amplitude and resonance frequency of complex impedance at the pile head decreased with the increase of slenderness ratio of pile; the inner soil attenuated vertical vibration of pipe pile to a certain extent; the more the softening (hardening) intensity of the surrounding soil was

the lower (higher) the amplitude of complex impedance became; the amplitude of complex impedance at the pile head increased (decreased) with the enlargement of softening (hardening) range due to construction disturbance. It is suggested that the radial inhomogeneity should be considered in the analysis of vertical vibration for pipe pile when the construction disturbance is distinct.