Analytical solution of dynamic response of cast-in-situ concrete thin-wall pipe piles under transient concentrated load with low strain

The plane-section assumption was not congruous in low strain dynamic tests on pipe piles,so the propagation of stress wave couldn’t be expressed by 1D wave equation.The difference of dynamic response of large diameter thin-wall pipe pile along the radial direction was neglectable,and the dynamic response was assumed to be the same along the radial direction,as a result,only variables z,θ and t were contained in the wave equation.The analytical solution of the wave equation was obtained by separation of variables and the method of variation of the parameters.A case history was analyzed to discuss the dynamic response at the top of pile and the influence of plane-section assumption on effective depth,and the results were also compared with the results of 1D wave theory and 3D FEM.