振動時における飽和砂の重量変動について

Abstract

This paper concerns the weight fluctuation of saturated sand caused by dynamic porewater pressure which is generated by the horizontal acceleration exerted on the ground-structure system. Authors pointed out theoretically the existence of the weight fluctuationof grain particle on the basis of the theory of buoyance for hydrostatic water pressureand the prediction was verified by the experiments which have been performed by usea glass ball and lump of grain particles.It is pointed out from these investigation that the weight fluctuation of saturatedsand is proportional to the vertical gradient of dynamic pore water pressure and to thevolume of grain particle. Therefore the weight fluctuation is most remarkable at thesurface of saturated sand layer and the magnitude of the fluctuation is to be comparedwith the buoyant force. Moreover, the effects on the liquefaction of saturated sandduring earthquake have been discussed.