【摘要】 利用DDS-70微机控制电磁式振动三轴仪,在均等固结条件下,对黄河口饱和粉土进行了不同预剪应力和预剪振次的循环三轴试验,探讨了循环预剪作用对饱和粉土的抗液化强度和孔隙水压力发展规律的影响.试验结果表明:低水平的循环预剪应力不会使饱和粉土在循环预剪阶段破坏;随着循环预剪应力和循环预剪振次的增加,饱和粉土的抗液化强度得到提高,但当循环预剪振次达到某一值时,抗液化强度趋于稳定.对振动孔隙水压力比-振次比进行归一化后发现:无循环预剪作用时饱和粉土孔压发展模式为双曲线,有循环预剪作用时为反正弦曲线,反正弦曲线拟合参数较小,约为0.2～0.4.更多还原

【Abstract】 Under the conditions of different cyclic preshearing stress and cyclic preshearing vibration times,cyclic triaxial tests on saturated silt of Yellow River estuary were conducted by DDS-70 microcomputer control electromagnetic vibration triaxial apparatus to study the liquefaction resistance and dynamic pore water pressure of saturated silt.The results show that the saturated silt is not failed under low cyclic preshearing stress in cyclic preshearing stage.The liquefaction resistance of saturated silt is increased with the increase of cyclic preshearing stress and cyclic preshearing vibration times.The liquefaction resistance reaches a stable value after a certain vibration times.Normalized relationship between vibration cycles and pore water pressure can be fitted by hyperbola and arcsine functions.The mode of pore water pressure is hyperbola without cyclic preshearing,while with it,the mode is arcsine with small fitting parameter of 0.2 to 0.4.更多还原