DYNAMIC GREEN’S FUNCTION FOR GIBSON SOIL SUBJECTED TO INTERNAL EXCITATION

The problems of Gibson subgrade subjected to interior harmonic excitation were investigated by Hankel integral-transform method. Integral contour was structured, and singular points on the contour were disposed specially to meet the radiation condition of wave. Dynamic Green’s function of Gibson subgrade subjected to interior harmonic excitation was thus obtained. By means of numerical quadrature, vertical surface displacement was evaluated and the influences of degree of non-homogeneity、excitation depth and excitation frequency in the subgrade were investigated. It was shown that: (1) depth and excitation frequency of load have large influence on the magnitude and the wave characteristic of vertical surface displacement; (2) degree of soil’s non-homogeneity has large influence on vertical surface displacement when subjected to low-frequency interior excitation.