Investigation of the Dynamic Behaviors of Frozen Saline Silt with the Use of a Spherical Stamp

摘要

The objective of this work was to study the dynamic interactions between a spherical indenter and frozen soil. Indentation via a spherical stamp was used for various dynamic applications with equal kinetic energy. This research is an attempt to add to the theoretical background for pile driving in permafrost. The focus is on the supposition that pile driving performed by a heavier hammer falling with a low velocity is more efficient than that done by a light hammer falling from a greater height at an equal kinetic energy. Monitoring of the force acting on the stamp during dynamic loading was performed for the first time with the use of a thin, flexible sensor placed between the stamp and the frozen soil sample. A plastic ball with a diameter of 25 mm was used as the spherical stamp, and the dynamic load on the stamp was provided by a falling dead weight. Artificial samples of frozen saline silt with a height of 35 mm and a diameter of 70 mm were used in the tests. The results show that the deformation behavior of frozen saline silt was significantly dependent on the impulse at a constant kinetic energy, and greater deformation was observed with increasing temperature in the range of the freezing point. An analytical solution that was previously used for ice was found to be suitable for the description of the investigated dynamic processes.