EXPERIMENTAL VERIFICATION OF ROTATIONAL COMPONENTS OF EARTHQUAKE MOTIONS DERIVED FROM SURFACE WAVES

At present, the rotational components of earthquake motions are mainly obtained from the translational components based on the theory of elastic wave propagation. However, this method has not been confirmed by strong motion observations. Surface wave experiment was used to verify the theoretical method. The results show that the method to calculate the rotational components is rational and effective. The experiment was conducted using ground hammering. The ground was assumed to be elastic semi-infinite space. The surface waves (Rayleigh wave and Love wave) were derived at the ground surface using measuring equipments at different locations. The rotational components could then be obtained approximately using deferential method. Comparing between the experimental results and the theoretical ones using the time histories and Fourier spectra, it is concluded that the acceleration time histories in the two approaches were consistent in the full range of earthquake motion, and the amplitudes, the number of peak and the shapes of the spectra are also close to each other for the Fourier spectra.