Numerical And Experimental Analyses On Dynamics Of Saturated Ground At High Frequencies

As the effective method of densifying sandy soils, vibroflotation has been used widely around the world. But some difficult problems were gradually discovered. When vibroflotation was used to deal with deep deposits of sand or complex geology, the effect of improvement was not as good as people's expection in advance. And the slow velocity of drilling, the unsatisfactory improvement and the phenomena of difficult drilling were also discovered. It is difficult to deal with these problems only by depending on electric vibrator. So imported vibrator of high-frequency has been used in the foundation treatment of some large construction. Because of high frequency, strong vibration ability, strong penetration ability, large output power and so on, imported vibrator of high-frequency can deal with these problems that electric vibrator can not deal with. It also can penetrate without water of pressure, and is suitable for different condition.However, there is little work on the research of dynamic behavior of soil under high frequencies. It is not advantaged for the development and wide use of this mechanism. The paper mainly focuses on the research of saturated sand foundation at high frequencies through finite-difference computer codes FLAC. The relationship between vibration frequency and time of vibration, pore water pressure and the acceleration of soil will be study. The effect of vibration frequency on the liquefaction of sand foundation will be researched.Piling with high-frequency vibration has been developed and widely used abroad in recent 10 years. It is significative to study the mechanism of piling with high-frequency vibration for the development and use of vibrator of high-frequency. The monitoring research of the piling on saturated foundation at high frequencies is done to analyze the effect of frequency on the acceleration, the velocity, the displacement of the pile and the soil. It is doable for our countries to develop vibrator of high-frequency through the result of research.The research work in this paper was supported by the Natural Science Foundation of China with the grant number 50779034.