Fluidization Phenomena in Soils During Vibro-Compaction and Vibro-Pile-Driving and -Pulling

摘要

Investigations dealing with response of soils to sinusoidal force excitation were conducted to determine: under what conditions fluidization can be obtained, particularly the correlation between the required magnitude, direction and frequency of the vibratory surface loads; and the character of the liquefied soil volume with respect to dimensions and sustainability. Fluidization, representing the change of soils from a solid into a quasi-fluid state by means of vibratory forces, is discussed. The hydrodynamic state is of particular importance for vibratory compaction and vibratory-pile driving and pulling. Experiments 'in situ' and in the laboratory are described. The response of soils to static and dynamic loads was analyzed to determine the prerequisites for liquefaction. Results indicate that under certain conditions a thin discrete zone in the immediate vicinity of the exciting source exists which shows characteristics similar to those of a viscoelastic fluid. (Author)