Influence factor study on relative horizontal displacement of underground rock powerhouse under earthquake

The influence of depth attenuation, in-suit stress field, damping ratio, elastic modulus, peak acceleration, and frequency spectrum of input earthquake on the relative horizontal displacement of some underground rock powerhouse is analyzed by FLAC^3D. It is shown that the in-suit stress field and elastic modulus are of small influence on the relative horizontal displacement. The maximum relative horizontal displacement will decrease steadily with damping ratio, and increase linearly with peak acceleration. The frequency spectrum is of great influence on the displacement. If the dominant frequency of input earthquake approaches the natural frequency of underground caverns, the maximum relative horizontal displacement will increase markedly. The study results could be used as a primary guidance to the anti-earthquake design for underground caverns.