Abstract: Dynamic response characteristics including pore water pressure, axial strain of marine soft soil under impact loading are studied through triaxial test. Bound water content of saturated soft clay is obtained by thermal gravimetric analysis and theoretical calculation method before and after triaxial experiments. Research shows that water content ranged from 15.6% to 23.5%, bound water content ranged from 17.6% to 29.4%, volume coefficient is 2.1%-9.5% before and after under impact loading. Drainage consolidation of saturated soft clay is obvious, variation of bound water content is large before and after under impact loading. The law of dynamic discharge water of marine soft soil is different from law of static discharge water. The results reveal that main factors are initial water content, bound water content, void ratio, state of soil and loading mode. Finally, the law of dynamic discharge water of marine soft soil and its inspiration is summarized. The study results can provide reference for engineering design of soft soil foundation treatment.

Key words: marine soft clay, impact loading ;bound water, triaxial test, thermal gravimetric analysis