The Characteristics Of Silt Liquefaction Induced By A Vibrator With Super High Frequency And Its Applications

Liquefaction is very common in the earthquakes. The foundations of constructions lost efficacy,a large number of buildings were damaged due to liguefaction. However,liquefaction is friendly used in engineering practice. For examples,the basic principle of vibration grouting technique is adopted to treat soft land. Roller Compacted Concrete (RCC) is formed by"vibration and then rolled".This study focused on fully saturated silt. Under different conditions, the cone resistances of fully saturated silt were measured by a static penetrometer.In order to comparing the resistances pre and post vibrations,the influences of vibration time,frequencies,and distance away from the vibration source on the liquefaction characteristics were discussed; furthermore,the viscosity of the liquefied silt was measured using a viscometer,and the viscosity results for different cases were compared to find the silt's rheological features. It was found in this study that: 1) Under different vibration time,the longer the vibration time is,the more the liquefaction effect would generally have,neverthness,there is a critical liquefaction time,which means if the vibration time is longer than the critical liquefaction time, the liquefaction effect would no longer increase; 2) Under the different vibration distance,the farther vibration distance is,the less the silt liquefaction would become,but as the vibration distance becomes farther, the vibration effect would get weak. 3) The higher vibration frequency is, the better the liquefaction would be. When the vibration frequency is close to silt inherent frequency,the liquefaction behaves the most. 4) After high frequency vibrations was applied , the silt apparent viscosity was significantly decreased,a shear thinning phenomenon exists. The liquefied silty still belongs to a kind of non-newtonian fluid,i.e.,the power-law fluid.