doi:10.3850/GI152

ABSTRACT

A new form of driven cast-in-place concrete large-diameter pipe pile (referred as PCC pile) developed independently by Geohohai has been patented in China. It has been widely applied in reinforcing soft soil for its larger side frictional resistance and less concrete used compared to common piles. Considering the viscous damping of the soil and soil-pile vertical coupled vibration, the differential equations and boundary conditions about vertical vibration of PCC piles in axisymmetric homogeneous viscoelastic soil are established. The analytical solution in frequency domain is deduced by Laplace transformation method. The responses in time domain are obtained by Fourier inverse transformation. A case study is given, and the results of analytical solution can well match the FEM results. Moreover, the influencing factors about the damping coefficient of the soil, the damping coefficient of the substratum have been studied. By analyzing the effect of viscous damping coefficient on velocity admittance and complex dynamic stiffness, the regularity of variations of vertical vibration characteristic with different parameters is obtained. The results indicate that the parameters of the outer soil have more distinctive effect on dynamic responses than that of the inner soil.

Keywords: PCC pile; soft soil; dynamic response; analytical solution; dynamic stiffness.

© 2010 by Geotechnical Society of Singapore (GeoSS)