Much destruction would be caused by vibration in various natural disasters. The dynamic characteristic of sand

especially liquefaction characteristic

has been studied for a long time

while in comparison the history of the study of dynamic characteristic of silty soil is relatively short. Liquefaction is known to be caused by earthquake shaking

with the state of soil changing from solid to liquid. Silty soil is one of the engineering soils in nature of special interest

with distinct characteristics from those of sand. Silty soil has three kinds of properties

i.e.

sand content

silt content and clay content

each of which has different dynamic characteristics including liquefaction characteristic. The influence is summarized of the three kinds of properties on dynamic modulus and dynamic damping. The functions of modulus and damping are also proposed. The tests have demonstrated that the dynamic characteristic of silty soil follows the general rule of non-linearity and hysteresis in soil. Liquefaction is a special issue related to the soil strength. The main methods for predicting the possibility of silt liquefaction are empirical method?SPT method?Seed method?FEM

and etc. The laboratory study is aiming at the determination of the dynamic characteristics through dynamic tests. The liquefaction characteristics of silty soils have been studied under various kinds of conditions. The influence of the clay content in silty soil is specially studied. The results of laboratory tests show that great differences exist between silty and sandy soil in response to pore water pressure. Finally

the mechanism of silt liquefaction is analyzed and the future studies about silt dynamic character are also suggested.