To employ the present method, the radius function of the quasi-ellipse cross section of the caisson foundation is first expanded into a Fourier series. As an example, Eq. (38) gives the
formula of the radius function in the case of α = 0o. Fig. 16 shows
the comparison of the actual shape of the curve of the cylinder
surface and the approximate fitting curves by the Fourier series with the truncated order of 2 and 14, respectively. From the figure, the expanded Fourier series can be effectively used to represent